No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Blood pressure and cognitive function: A prospective analysis among adolescents in Seychelles
Abstract
Objective:
An inverse relationship between blood pressure (BP) and cognitive function has been found in adults, but limited data are available in adolescents and young adults. We examined the prospective relation between BP and cognitive function in adolescence.
Methods:
We examined the association between BP measured at the ages of 12-15 years in school surveys and cognitive endpoints measured in the Seychelles Child Development Study at ages 17 (n = 407) and 19 (n = 429) years, respectively. We evaluated multiple domains of cognition based on subtests of the Cambridge Neurological Test Automated Battery (CANTAB), the Woodcock Johnson Test of Scholastic Achievement (WJTA), the Finger Tapping test (FT) and the Kaufman Brief Intelligence Test (K-BIT). We used age, sex and height-specific z-scores of SBP, DBP and mean arterial pressure (MAP).
Results:
Six out of the 21 cognitive endpoints tested were associated with BP. However, none of these associations were found to hold for both males and females or for different subtests within the same neurodevelopmental domain or for both SBP and DBP. Most of these associations disappeared when analyses were adjusted for selected potential confounding factors such as socio-economic status, birth weight, gestational age, BMI, alcohol consumption, blood glucose, and total n-3 and n-6 polyunsaturated fats.
Conclusions:
Our findings do not support a consistent association between BP and subsequent performance on tests assessing various cognitive domains in adolescents.
... Two of the studies did not report details of the procedure used for blood pressure measurement, 18,23 two studies provided comprehensive details 19,21,22 and another study leveraged data collected in school surveys. 20 All studies used some level of neuropsychological battery for cognitive testing. ...
... Lyngdoh et al. 20 Further adjustment for baseline blood pressure level did not appreciably change the association between areas under the curve effects and cognition. Finally, after adjustment for incident cardiovascular events, the associations between blood pressure areas under the curve and cognitive function remained statistically significant, but effect sizes were reduced. ...
... Miller et al. 18 Lande et al. 19 Lyngdoh et al. 20 Reis et al. 21 and Yaffe et al. 22 Rovio et al. 23 Did they ask a clearly focused issue? ...
Introduction
High blood pressure in midlife is an established risk factor for cognitive decline and dementia but less is known about the impact of raised blood pressure on cognition in childhood and early adulthood.
Method
We systematically reviewed and quantified the existing evidence base relating to blood pressure in early life and subsequent cognitive performance. Medline, Embase, PsycINFOo, Scopus, and Web of Science were searched from inception to July 2020. We included longitudinal cohort and case–control studies involving participants aged 0–40 years with a baseline and at least one follow-up blood pressure assessment alongside at least one measure of cognition, occurring at the same time as, or subsequent to blood pressure measures. Risk of bias was assessed independently by two reviewers. PROSPERO registration CRD42020214655.
Results
Of a total of 5638 records identified, three cohort and two case–control studies were included with ages ranging from 3 to early 30s. Repeated blood pressure measurements averaged over 25 years or cumulative blood pressure in the 25–30 years prior to assessment of cognitive function were associated with poorer cognitive performance in the two largest cohort studies. The smallest cohort study reported no evidence of an association and the results from the two case–control studies were contradictory. All studies were at risk of bias.
Conclusion
Overall, the evidence in this area is lacking and study quality is mixed. Our review highlights an urgent need for studies evaluating the potential for a relationship between raised blood pressure and poorer cognition in early life given the potential for possible risk reduction if such a relationship exists.
... Effects of hypertension on cognitive function in adults are known but studies conducted in children are scarce [48]. Emerging studies suggest that long before a hypertensive child or adolescent develops any clinically evident neurologic symptoms or signs, there can be subclinical changes affecting different domains of neurocognitive function, including executive functioning, attention, and memory (Table 1) [49][50][51][52]. ...
... A higher prevalence of learning disability has been reported in children with sustained hypertension, even when children with attention deficit hyperactivity disorder are excluded from the analysis [55]. Although the association of hypertension with cognitive performance is inconsistently reported, awareness and recognition of cognitive deficits in school-aged children and adolescents is imperative as the possibility of repeated injury to the brain increases over time (Table 1) [52]. Under-recognized neurocognitive deficits in hypertensive children and adolescents may evolve to cognitive decline during adulthood [48,52,56]. ...
... Although the association of hypertension with cognitive performance is inconsistently reported, awareness and recognition of cognitive deficits in school-aged children and adolescents is imperative as the possibility of repeated injury to the brain increases over time (Table 1) [52]. Under-recognized neurocognitive deficits in hypertensive children and adolescents may evolve to cognitive decline during adulthood [48,52,56]. In a study of 75 children with newly diagnosed untreated sustained hypertension, decreased performance is reported in neurocognitive measures of attention, learning, memory, and fine motor dexterity compared to a normotensive group [50]. ...
Purpose of Review
Pediatric hypertension is increasing in incidence with concomitant increases in childhood obesity. Target organ damage from primary or secondary pediatric hypertension is a growing concern, as the pathogenesis of vascular disease, typically observed later in life, may begin at a young age. While hypertensive complications are described extensively in adults, much less is known about end organ damage from elevated blood pressure in children and adolescents.
Recent Findings
This review highlights the recent advances describing the target organ damage in the macro- and microvasculature resulting from hypertension. Persistently elevated blood pressure in childhood is associated with vascular changes affecting the heart, brain, kidneys, and retina. Emerging research shows that elevated blood pressure in children has effect on neurocognitive function in specific domains such as executive functioning, attention, and memory. Microalbuminuria is an early marker of kidney disease and a sign of glomerular injury and endothelial dysfunction that increases the risk of kidney damage and is associated with future kidney and cardiovascular events. Screening with ambulatory blood pressure monitoring to improve blood pressure control and echocardiogram may aid in early prevention of end organ damage.
Summary
In this review, we summarize and critically evaluate recent findings, describe ongoing studies, and address future research questions. Implications for diagnosis, prognosis, and need for better control of hypertension are also discussed.
... Literature, over the past decade, suggests that the hyper/hypotension, obesity, underweight, and hyperlipidemia are associated with cognitive decline in patients; however, the mechanism(s) by which abnormal blood pressure, body weight, and dyslipidemia affect human cognition remains unexplored. Studies on the relationship between cardiometabolic risk factors and cognitive function in normal population could provide researchers with evidence to establish relative mechanisms [17]. Previous exploratory studies with sampling from general population appear to be mainly based on evidence from adult, yet rarely in young persons. ...
... As mentioned by Lyngdoh et al. [17], data from randomized controlled trials could provide convincing evidence to explore the mechanisms of the impact of cardiometabolic risk factors on cognitive function. Studies on the relationship between cardiometabolic risk factors and cognitive function in adolescent are rare. ...
... With respect to the blood pressure, previous exploratory studies with sampling from general population revealed inconsistent results in investigating the association between blood pressure and cognitive performance. The finding of this study parallels recent evidence, in large adolescent populations, that there is no consistent association between BP and cognitive performance [17,42]. It is important to note that Lande et al. [42] reported children with elevated systolic BP (SBP ≧ 90th percentile, = 288) had lower average scores compared with normotensive children (SBP < 90th percentile, = 4789) for digit span, block design, and mathematics in a nationally representative sample of 5077 children aged 6-16 years in the US (NHANES III). ...
This exploratory study examines the relationship between cardiometabolic risk factors (blood pressure, waist circumference, BMI, and total cholesterol) and cognitive/academic performance. In this study, 1297 Taiwanese tenth-grade volunteers are recruited. Scores from the Basic Competency Test, an annual national competitive entrance examination, are used to evaluate academic performance. Cognitive abilities are accessed via the Multiple Aptitude Test Battery. The results indicate that systolic blood pressure is significantly, negatively associated with academic performance, both in male and female subjects. BMI and waist circumference are associated with verbal reasoning performance with an inverse U-shaped pattern, suggesting that both low and high BMI/waist circumference may be associated with lower verbal reasoning performance.
... Among 23 777 adolescents with sex-specific data, the pooled SBP was 112 mm Hg (95% CI 109 to 115) and the pooled DBP was 67 mm Hg (65 to 68) in male participants versus a pooled SBP of 111 mm Hg (109 to 113) and a pooled DBP of 68 mm Hg (67 to 69) in female participants. The mean difference in SBP levels between male adolescents and female adolescents was 1·13 mm Hg (95% CI -0·56 to 2·82; p<0·0001) and the mean difference in DBP levels between male adolescents and female adolescents was -1·21 mm Hg (-1·71 to -0·71; p<0·0001; appendix pp [21][22] ...
... Overall, the natural history of hypertension and subsequent end-organ damage across the lifespan in 20 Goon et al (2013) 21 Lyngdoh et al (2013) 22 Ujunwa et al (2013) 23 Mushengezi and Chillo (2014) 24 Nkeh-Chungag et al (2015) 25 Oyeyemi et al (2015) 26 Awotidebe et al (2016) 27 Kagura et al (2016) 28 Etyang et al (2018) 32 Monyeki et al (2017) 30 Ezeudu et al (2018) 33 Muhihi et al (2018) 34 Muyumba et al (2018) 35 Omisore et al (2018) 36 Abiodun et al (2019) 38 Azupogo et al (2020) 42 Katamba et al (2020) 43 Masocha et al (2020) 44 Mokgwathi and Mwita (2020) 45 Raphadu et al (2020) 46 Sungwa et al (2020) 47 du Plessis et al (2021) 48 Shokunbi and Ukangwa (2021) ...
Background:
More people from sub-Saharan Africa aged between 20 years and 60 years are affected by end-organ damage due to underlying hypertension than people in high-income countries. However, there is a paucity of data on the pattern of elevated blood pressure among adolescents aged 10-19 years in sub-Saharan Africa. We aimed to provide pooled estimates of high blood pressure prevalence and mean levels in adolescents aged 10-19 years across sub-Saharan Africa.
Methods:
In this systematic review and meta-analysis, we searched PubMed, Google Scholar, African Index Medicus, and Embase to identify studies published from Jan 1, 2010, to Dec 31, 2021. To be included, primary studies had to be observational studies of adolescents aged 10-19 years residing in sub-Saharan African countries reporting the pooled prevalence of elevated blood pressure or with enough data to compute these estimates. We excluded studies on non-systemic hypertension, in African people not living in sub-Saharan Africa, with participant selection based on the presence of hypertension, and with adult cohorts in which we could not disaggregate data for adolescents. We independently extracted relevant data from individual studies using a standard data extraction form. We used a random-effects model to estimate the pooled prevalence of elevated blood pressure and mean systolic blood pressure (SBP) and diastolic blood pressure (DBP) levels overall and on a sex-specific basis. This study is registered with PROSPERO (CRD42022297948).
Findings:
We identified 2559 studies, and assessed 81 full-text studies for eligibility, of which 36 studies comprising 37 926 participants aged 10-19 years from ten (20%) of 49 sub-Saharan African countries were eligible. A pooled sample of 29 696 adolescents informed meta-analyses of elevated blood pressure and 27 155 adolescents informed meta-analyses of mean blood pressure. Sex data were available from 26 818 adolescents (14 369 [53·6%] were female and 12 449 [46·4%] were male) for the prevalence of elevated blood pressure and 23 777 adolescents (12 864 [54·1%] were female and 10 913 [45·9%] were male) for mean blood pressure. Study quality was high, with no low-quality studies. The reported prevalence of elevated blood pressure ranged from 4 (0·2%) of 1727 to 1755 (25·1%) of 6980 (pooled prevalence 9·9%, 95% CI 7·3-12·5; I?=99·2%, pheterogeneity<0·0001). Mean SBP was 111 mm Hg (95% CI 108-114) and mean DBP was 68 mm Hg (66-70). 13·4% (95% CI 12·9-13·9; pheterogeneity<0·0001) of male participants had elevated blood pressure compared with 11·9% (11·3-12·4; pheterogeneity<0·0001) of female participants (odds ratio 1·04, 95% CI 0·81-1·34; pheterogeneity<0·0001).
Interpretation:
To our knowledge, this systematic review and meta-analysis is the first systematic synthesis of blood pressure data specifically derived from adolescents in sub-Saharan Africa. Although many low-income countries were not represented in our study, our findings suggest that approximately one in ten adolescents have elevated blood pressure across sub-Saharan Africa. Accordingly, there is an urgent need to improve preventive heart-health programmes in the region.
Funding:
None.
... However, for at least one of these risk factors, sustained high BP, the relationship to cognitive functioning is complex. Reviews on this relationship have yielded mixed conclusions (Novak & Hajjar, 2010;Qiu et al., 2005;Reitz & Luchsinger, 2007), in keeping with the rather inconclusive findings in the primary studies (e.g., Harrington et al., 2000;Lande et al., 2003;Lyngdoh et al., 2013;Tzourio et al., 1999). Here, we address the heterogeneity in these results. ...
... This differs from the bulk of the existing literature that focused on either children but mostly on the elderly. Studies in children are limited by the relatively few children showing hypertension, which is then often complicated in those children by comorbid disorders and congenital disease (Cha et al., 2012;Lande et al., 2003;Lyngdoh et al., 2013). Studies in the elderly are complicated by comorbidity of high BP with other atherosclerotic risk factors like cholesterol, diabetes, body mass index (BMI), immune parameters, and medical or psychiatric disorders, which can all assert an influence on cognitive functioning (Spauwen et al., 2015;van Vliet et al., 2010;Waldstein, 2003;Walther et al., 2010). ...
The large body of literature on the association between blood pressure (BP) and cognitive functioning has yielded mixed results, possibly due to the presence of non-linear effects across age, or because BP affects specific brain areas differently, impacting more on some cognitive skills than on others. If a robust association was detected among BP and specific cognitive tasks, the causal nature of reported associations between BP and cognition could be investigated in twin data, which allow a test of alternative explanations, including genetic pleiotropy. The present study first examines the association between BP and cognition in a sample of 1,140 participants with an age range between 10 and 86 years. Linear and quadratic effects of systolic BP (SBP) and diastolic BP (DBP) on cognitive functioning were examined for 17 tests across five functions. Associations were corrected for effects of sex and linear and quadratic effects of age. Second, to test a causal model, data from 123 monozygotic (MZ) twin pairs were analyzed to test whether cognitive functioning of the twins with the higher BP was different from that of the co-twins with lower BP. Associations between BP and cognitive functioning were absent for the majority of the cognitive tests, with the exception of a lower speed of emotion identification and verbal reasoning in subjects with high diastolic BP. In the MZ twin pair analyses, no effects of BP on cognition were found. We conclude that in the population at large, BP level is not associated with cognitive functioning in a clinically meaningful way.
... Most of the studies that have analyzed how CVD risk may influence later academic performance in adolescents have investigated this link focusing only on individual CVD risk factors. These studies showed both significant (Álvarez-Bueno et al., 2020;García-Hermoso et al., 2021;Larsen et al., 2014) and nonsignificant (Lyngdoh et al., 2013) results depending on the individual CVD risk factor analyzed, without considering other risk factors that tend to accumulate or occur altogether. In this context, this is the first study that examines the longitudinal association between a composite score of CVD risk for youth and academic performance, which hampers direct comparisons with other studies. ...
Introduction
The limited prior research examining the association between academic performance and cardiovascular disease (CVD) risk factors in youth did not explore the reciprocal association between these constructs, and analyzed CVD risk factors individually. Thus, the aim of the present study was to explore the bidirectional longitudinal association between clustered CVD risk score and academic performance in adolescents over a 24‐month interval.
Methods
A total of 237 adolescents (45.6% girls), aged 13.9 ± 0.3 years old at baseline, from DADOS (Deporte, ADOlescencia y Salud) study were included in this study. A clustered CVD risk score was created by calculating the mean age‐ and gender‐standardized z ‐scores of waist circumference, systolic blood pressure, total cholesterol to high‐density lipoprotein cholesterol ratio, triglycerides, homeostatic model assessment of insulin resistance, and cardiorespiratory fitness (inversed). Academic performance was assessed through the final academic grades and the test of educational abilities.
Results
Our results showed that the clustered CVD risk score at baseline was not associated with academic performance 24 months later (all p > .05). Nevertheless, except for physical education, academic grades at baseline were inversely associated with clustered CVD risk score at follow‐up in adolescents (β ranged from −0.140 to −0.102; all p < .05). No associations were found between academic abilities at baseline and clustered CVD risk score at follow‐up (all p > .05).
Conclusion
Academic grades could help predict CVD risk 24 months later during adolescence. Education professionals should foster adolescents' academic performance not only to improve academic results but also to maximize future cardiovascular health benefits.
... The search yielded 1,316 individual results from the two databases, of which 13 met the eligibility criteria (Figure 1). Additionally, six articles provided data on the relationship between BP and cognitive domains in the pediatric population but made no distinction of AH groups (24)(25)(26)(27)(28)(29). ...
Arterial hypertension (AH) among adults is known to be associated with worse cognitive outcomes. Similarly, children and adolescents with AH could be expected to underperform during neuropsychological evaluations when compared with healthy peers. Our aims were to review the existing literature on cognitive functioning among children and adolescents with primary AH and to identify what additional evidence may be needed to substantiate the impact of hypertension on poor cognitive outcomes in this population. We conducted a systematic review of articles in PubMed and Web of Science published before 17 January 2022, reporting on cognitive testing among children and adolescents with primary AH. From 1,316 records, 13 were included in the review—7 used battery-testing while other employed indirect measures of cognitive functions. Most of the studies reported worse results among individuals with AH. Results of two prospective trials suggested that cognitive functioning may improve after starting antihypertensive treatment. Ambulatory blood pressure monitoring was shown to be more strongly related to cognitive testing results than office measures of blood pressure. Significant confounders, namely obesity and sleep apnea, were identified throughout the studies. Our review indicates that evidence relating AH with poor cognitive functioning among youth is usually based on indirect measures of executive functions (e.g., questionnaires) rather than objective neuropsychological tests. Future prospective trials set to test different cognitive domains in children and adolescents undergoing treatment for AH are endorsed and should consider using standardized neuropsychological batteries as well as adjust the assessing results for obesity and sleep disorders.
... BP is a complex condition, and various factors, including heredity, physiology, environmental reaction, lifestyle, etc., influence it [6,7]. Although these quantitative traits have been extensively studied, various studies have reported phenotypic associations among all three traits; therefore, a common SNP-based study of the association becomes essential [8][9][10][11][12][13][14][15]. To our knowledge, no common SNPs or polymorphisms have been categorized concerning these three quantitative variables, namely BMI, IQ and BP. ...
Background
Single nucleotide polymorphism (SNP) variants are abundant, persistent and widely distributed across the genome and are frequently linked to the development of genetic diseases. Identifying SNPs that underpin complex diseases can aid scientists in the discovery of disease-related genes by allowing for early detection, effective medication and eventually disease prevention.
Main body
Various SNP or polymorphism-based studies were used to categorize different SNPs potentially related to three quantitative traits: body mass index (BMI), intelligence quotient (IQ) and blood pressure, and then uncovered common SNPs for these three traits. We employed SNPedia, RefSNP Report, GWAS Catalog, Gene Cards (Data Bases), PubMed and Google Scholar search engines to find relevant material on SNPs associated with three quantitative traits. As a result, we detected three common SNPs for all three quantitative traits in global populations: SNP rs6265 of the BDNF gene on chromosome 11p14.1, SNP rs131070325 of the SL39A8 gene on chromosome 4p24 and SNP rs4680 of the COMT gene on chromosome 22q11.21.
Conclusion
In our review, we focused on the prevalent SNPs and gene expression activities that influence these three quantitative traits. These SNPs have been used to detect and map complex, common illnesses in communities for homogeneity testing and pharmacogenetic studies. High blood pressure, diabetes and heart disease, as well as BMI, schizophrenia and IQ, can all be predicted using common SNPs. Finally, the results of our work can be used to find common SNPs and genes that regulate these three quantitative features across the genome.
... For example, a large longitudinal study of children in the Seychelles found only scattered correlations between BP assessed at ages 12-15 and subsequent cognition at ages 17 and 19; correlations which did not survive corrections of number of comparisons and body mass index. 20 In contrast, a large study of Finnish children found a longitudinal relationship between BP as a youth (ages 3-18) and cognitive skill tested 31 years later in midlife. 21 Interestingly, among hypertensive children, the cerebrovascular reactivity to hypoxia has been related to the cognitive function-suggesting a brain-blood flow basis for the correlations. ...
The brain's relationship to essential hypertension is primarily understood to be that of an end-organ, damaged late in life by stroke or dementia. Emerging evidence, however, shows that heightened blood pressure (BP) early in life and prior to traditionally defined hypertension, relates to altered brain structure, cerebrovascular function, and cognitive processing. Deficits in cognitive function, cerebral blood flow (CBF) responsivity, volumes of brain areas, and white matter integrity all relate to increased but pre-hypertensive levels of BP. Such relationships may be observed as early as childhood. In this review, we consider the basis of these relationships by examining the emergence of putative causative factors for hypertension that would impact or involve brain function/structure, e.g., sympathetic nervous system activation and related endocrine and inflammatory activation. Currently, however, available evidence is not sufficient to fully explain the specific pattern of brain deficits related to heightened BP. Despite this uncertainty, the evidence reviewed suggests the value that early intervention may have, not only for reducing BP, but also for maintaining brain function.
... Generally, learning and as concentration during learning. It has also been used in measuring individual concentration in different aspects [14]. ...
Learning style is deemed crucial for different types of age groups. It is essential, especially for individual learning achievement. Learning is a part of cognitive processes affecting the human central nervous system, which can be monitored by using the physiological signals. In this study, physiological signals thus are proposed as key attributes for the classification of learning styles to avoid biased data from completing the questionnaire and promote the real-time response in the classroom environment. More specifically, heart rate and blood pressure signals are chosen for this study. Following the VARK model, the physiological signals of learners are classified with the decision tree into four different types, including visual, aural, read and write, and kinesthetic learners. There are 40 primary school children and 30 university students involved in the whole study. The results show that the proposed factors obtain 85% and 90% classification accuracy for children and university students, respectively. Both heart rate and blood pressure are thus reasonably impacted as the classification attributes.
... Mild hypertension in children in young adults causes decreased performance in neuropsychologic test compared to control [6]. Children with chronic hypertension are at higher risk to have learning disturbances and executive function deficits, where cognitive impairments hits the prevalence number of 2.4% [1,7]. ...
Background: The prevalence of hypertension is increasing in childhood and usually asymptomatic but still has target organ damage manifestations. This condition may cause negative impacts on their cognitive function. Early detection and appropriate management on hypertension may lessen cognitive impairment associated with hypertension.
... Cardiovascular risk factors negatively and significantly correlated with 2009 SIMCE outcomes only in school-age children of 2010 1HSG and in both 2009 SIMCE tests, with the exception of smoking, although these results did not contribute to explain the results. Other findings do not support the existence of consistent associations between blood pressure and subsequent performance in tests assessing various cognitive domains in adolescents [88]. ...
The aim of this study was to quantitate the relative impact of nutritional, intellectual, brain development, cardiovascular risk, socio-economic, demographic and educational variables on the results of the 2009 Quality Education Measurement System (SIMCE) tests of language and mathematics for scholastic achievement (SA) applying a multifactorial approach, in school-age children of the 2010 5th elementary school grade (5ESG) and of the 1st grade of high school (1HSG). The purposes were: i) to test the hypothesis that intellectual ability, the level of SA of the educational establishments in the 2009 SIMCE tests, sex, parental schooling levels, and head circumference-for-age Z-score are the most relevant parameters associated with 2009 SIMCE outcomes; ii) to determine the predictive ability of the 2009 SIMCE results in determining the 2013 SIMCE outcomes for the 2010 5ESG cohort (when they graduated from elementary school, 8th grade) and for determining the 2013 University Selection Test (PSU) outcomes for the 2010 1HSG group (for university admission, when they graduated from high school, 4th grade); iii) to determine the association between the 2009 SIMCE results with the 2017 PSU outcomes for the 2010 5ESG group (for university admission, when they graduated from high school, 4th grade). A representative, proportional and stratified sample of 33 schools of the Metropolitan Region of Chile was randomly chosen. In these schools, 1,353 school-age children of both sexes, of the 2010 5ESG (n = 682; mean age = 10.8 years, SD = 0.6) and of the 2010 1HSG (n = 671; mean age = 14.8 years, SD = 0.6) participated. In both grades and tests, the findings confirm the hypotheses formulated. 2009 SIMCE outcomes were positively and significantly associated with 2013 SIMCE and with 2017 PSU and, with 2013 PSU outcomes in school-age children from 2010 5ESG and 1HSG, respectively. These findings may be useful for educational and health planning in Chile and countries in a comparable stage of development.
... Indeed, a prospective study did not show associations between BP measured at the ages of 12 and 15 years with performance on tests assessing various cognitive domains 5 years later. 19 Still, it remains that a recent Mendelian randomization analysis using data from 6 independent genome-wide association studies consortia and the UK Biobank sample (n=112 151) provided no evidence for causal associations from physical health factors to later life cognitive ability; however, in the other direction, higher educational attainment (as a marker for cognitive ability in youth) predicted lower body mass index, SBP, type 2 diabetes mellitus, and coronary artery disease. Despite these phenotypic cognitive? ...
See Article by Lamballais et al.
... Wharton et al. (2006) also found a positive relationship between BP and the perfor-mance of visuospatial tasks (SBC 2010). In his turn, Lyngdoh et al. (2013) found an association between some cognitive functions and BP, though the associations were gender specific or, exclusively related to systolic BP (SBP) or to diastolic BP (DBP), thus precluding generalizations (Lundgren et. al., 2013). ...
The increase in global temperature in recent years (which is likely to continue) has the power to affect the temperatures of indoor workplaces. This increase may in turn, be reflected in human performance. The present article analyzes the relationship between air temperature, blood pressure and heart rate variation in students in a learning environment through Video Display Terminals (VDT), located in northeastern Brazil. The thermal conditions were analyzed during three consecutive days, according to ISO 7726: 1998; in the group of students who underwent changes in indoor air temperature, their blood pressure and heart rate were also measured. When the air temperature was of 20ºC, 24% of the subjects’ heart rate exceeded 100bpm, while for 30 °C this number reached 51%. The results revealed changes in diastolic blood pressure and heart rate when air temperature increases.
... Wharton et al. [32] found a positive relationship between BP and the performance of visuospatial tasks. Lyngdoh et al. [33] found an association between some cognitive functions and BP; however, the associations were gender specific or exclusively related to systolic BP (SBP) or diastolic BP (DBP), thus precluding their generalization. ...
Background:
The increase in air temperature has been associated with human deaths, some of which are related to cardiovascular dysfunctions, and with the reduction of physical and cognitive performance in humans.
Objective:
To analyze the relationship between blood pressure (BP) and heart rate (HR) and the cognitive performance of students who were submitted to temperature changes in classrooms.
Methods:
The university students answered a survey that was adapted from the Battery of Reasoning Tests over 3 consecutive days at different air temperatures while their thermal state and HR were measured. During those 3 days, BP and HR were evaluated before and after the cognitive test.
Results:
The average and final HR increased at high temperatures; the tests execution time was reduced at high temperatures; and the cognitive tests was related to Mean BP at the beginning of the test, the maximum HR during the test and the air temperature.
Conclusions:
The cognitive performance of undergraduate students in the field of engineering and technology will increase while performing activities in a learning environment with an air temperature of approximately 23.3°C (according to their thermal perception), if students have an initial MBP of 93.33 mmHg and a 60 bpm HRmax.
... A recent study in adolescents of the Seychelles Child Development study failed to find associations between BP measured at 12 to 15 years of age and cognitive function measured at both 17 and 19 years of age. 112 It may be that underlying physiological mechanisms linking hypertension and cognition may not be in play at such a young age. It is also possible that the tests used do not capture the variability in cognition that is associated with high BP at a young age. ...
Background:
Age-related dementia, most commonly caused by Alzheimer disease or cerebrovascular factors (vascular dementia), is a major public health threat. Chronic arterial hypertension is a well-established risk factor for both types of dementia, but the link between hypertension and its treatment and cognition remains poorly understood. In this scientific statement, a multidisciplinary team of experts examines the impact of hypertension on cognition to assess the state of the knowledge, to identify gaps, and to provide future directions.
Methods:
Authors with relevant expertise were selected to contribute to this statement in accordance with the American Heart Association conflict-of-interest management policy. Panel members were assigned topics relevant to their areas of expertise, reviewed the literature, and summarized the available data.
Results:
Hypertension disrupts the structure and function of cerebral blood vessels, leads to ischemic damage of white matter regions critical for cognitive function, and may promote Alzheimer pathology. There is strong evidence of a deleterious influence of midlife hypertension on late-life cognitive function, but the cognitive impact of late-life hypertension is less clear. Observational studies demonstrated a cumulative effect of hypertension on cerebrovascular damage, but evidence from clinical trials that antihypertensive treatment improves cognition is not conclusive.
Conclusions:
After carefully reviewing the literature, the group concluded that there were insufficient data to make evidence-based recommendations. However, judicious treatment of hypertension, taking into account goals of care and individual characteristics (eg, age and comorbidities), seems justified to safeguard vascular health and, as a consequence, brain health.
... Higher BP was independently associated with decreased IQ scores in children with mild-to-moderate CKD [510]. A prospective analysis among adolescents in Seychelles, however, did not support a consistent association between BP and subsequent performance on tests assessing various cognitive domains in adolescents [511]. Cerebral vascular reactivity, known to be associated with cognitive function, was shown to be blunted in hypertensive children and adolescents [512]. ...
Hypertension (HTN) is a significant global health issue. It is the major risk factor for atherosclerosis, leading to the development of cardiovascular disease (CVD). There is increasing evidence that HTN has its antecedents during childhood and that atherosclerosis is already present in adolescents. Thus, early detection and intervention are crucial. HTN is also a risk factor for the progression to end-stage renal disease, a topic extremely relevant to pediatric nephrologists. While younger children are more likely to have secondary HTN, the prevalence of primary HTN is increasing among school children and adolescents due to an epidemic of obesity. To identify children with HTN, clinicians need to measure blood pressure (BP) routinely and know normative values as well as the definition of HTN. Prevalence of HTN, factors influencing BP, and sequelae of childhood HTN are also reviewed in this chapter.
Introduction
Hypertension (HTN) among adolescents is common in high-income countries, and leads to increased premature cardiovascular diseases (CVD). In sub-Saharan Africa (SSA), the prevalence of HTN among adolescents, associated risk factors and CVD complications are not well-described. Such data is needed for planning public health programs to prevent premature CVD in SSA.
Methods
We systematically searched 5 databases (MEDLINE, Embase, Google Scholar, Web of Science, and African Index Medicus) from their establishment to December 2021. Key search terms were: adolescent, arterial hypertension, and names of the 48 countries in SSA. We used Covidence® to manage the search results. The review was registered in the Open Science Framework (OSF) https://osf.io/p5sbt/ .
Results
We identified 4,008 articles out of which we screened 3,088 abstracts, and reviewed 583 full-text articles. We finally included 92 articles that were published between 1968 to December 2021. The majority were cross-sectional studies (80%) and conducted in school settings (78%). The risk of bias was low for 59 studies (64.1%), moderate for 29 studies (31.5%), and high for 4 studies (4.3%). Overall, the prevalence of HTN varied widely from 0.18% to 34.0% with a median (IQR) of 5.5% (3.1%, 11.1%). It was relatively higher in studies using automated blood pressure (BP) devices, and in studies defining HTN using thresholds based on percentile BP distribution for one's height, age, and sex. In addition, the prevalence of HTN was significantly higher in studies from Southern Africa region of SSA and positively correlated with the year of publication. Across studies, traditional risk factors such as age, sex, body mass index, and physical inactivity, were commonly found to be associated with HTN. In contrast, non-traditional risk factors related to poverty and tropical diseases were rarely assessed. Only three studies investigated the CVD complications related to HTN in the study population.
Conclusion
The prevalence of HTN among adolescents in SSA is high indicating that this is a major health problem. Data on non-traditional risk factors and complications are scarce. Longitudinal studies are needed to clearly define the rates, causes, and complications of HTN.
Systematic Review Registration
https://osf.io/p5sbt/ , identifier (10.17605/OSF.IO/P5SBT).
Dementia is a global public health problem with increasing prevalence and incidence worldwide. The African continent is expected to bear the biggest brunt of the burden of dementia by 2050 because of the rapid demographic changes, including rapid population growth, an increase in life expectancy, and ageing. However, French-speaking Sub-Saharan African (FS-SSA) countries are underrepresented in research on dementia in Africa. While the reasons are diverse and complex, linguistic and cultural barriers to research, disproportionately affect these countries and may be significant factors. Any efforts, therefore, to redress the burden of dementia in Africa must consider the specific demographic, cultural, and linguistic characteristics of FS-SSA countries. This scoping review explores the current state of knowledge in dementia and cognitive impairment in Sub-Saharan Africa, highlighting research gaps and specific patterns unique to FS-SSA Africa. We identify pathways for research to bridge the knowledge gaps on dementia in FS-SSA as part of the global endeavor to tackle dementia worldwide.
Executive functions are part of the cognitive abilities that allow individuals to perform adequately multi-component tasks necessary in their daily life. This domain of intelligence underlies a wide range of cognitive processes that facilitate new ways of behaving and approaching unfamiliar circumstances. Certain conditions associated with executive dysfunction are highly prevalent in aging, such as high blood pressure (BP), diabetes mellitus and cardiovascular diseases. Previous research revealed substantial amount of data linking higher rates of BP with lower score on tests aimed at measuring attention and executive functions (Harciarek & Wojtowicz, 2017). Lower scores on tests of executive functioning have been found to be associated with hypertension in elderly patients (Bucur & Madden, 2010). Of particular interest, hypertension rates are alarming among Hispanics, yet studies examining executive functions and hypertension in Hispanics are scarce.
Long term, particularly uncontrolled hypertension causes cognitive impairment. The results of recent meta-analyzes on the effects of antihypertensive drug therapy on the inhibition of cognitive impairment are different. In some of them there was a small, but significant reduction in the risk of developing dementia, other did not confirm the beneficial effect of these drugs. In 2004, Fournier hypothesized that some antihypertensive drugs have properties inhibit the growth of cognitive impairment in patients with hypertension. These include calcium channel blockers, particularly sartans, that work by AT2 and AT4 receptors located in the brain tissue. Our study discusses the number of experimental researches in animals and in vitro studies, which indirectly confirm a significant positive influence sartans to reduce the risk of dementia in patients with hypertension. These drugs improve the cerebral blood flow, reduced in patients with impaired cognitive ability, have anti-inflammatory effect and reduce oxidative stress in brain tissue, and may also inhibit the deposition of beta-amyloid in the central nervous system. Clinical studies on this issue are still few. However, both epidemiological observations and relatively small observational studies indicate to the benefits of sartans in order to reduce the risk of dementia in patients with hypertension. This year was published meta- Analysis of Marpillat et al, which showed that in patients with uncomplicated hypertension only sartans (and up to 40%) reduce the risk of developing cognitive impairment. The current observations support the original hypothesis of Fournier and now sartans therapy gives hopes for a more effective prevention of dementia in patients with hypertension.
Evidence from the Seychelles Child Development Nutrition Study suggests that maternal nutritional status can modulate the relationship between prenatal methylmercury (MeHg) exposure and developmental outcomes in children. The aim of this study was to investigate whether maternal PUFA status was a confounding factor in any possible associations between prenatal MeHg exposure and developmental outcomes at 5 y of age in the Republic of Seychelles. Maternal status of (n-3) and (n-6) PUFA were measured in serum collected at 28 wk gestation and delivery. Prenatal MeHg exposure was determined in maternal hair collected at delivery. At 5 y of age, the children completed a comprehensive range of sensitive developmental assessments. Complete data from 225 mothers and their children were available for analysis. Multiple linear regression analyses revealed Preschool Language Scale scores of the children improved with increasing maternal serum DHA [22:6(n-3)] concentrations and decreased with increasing arachidonic acid [20:4(n-6)] concentrations, albeit verbal intelligence improved with increasing (n-6) PUFA concentrations in maternal serum. There were no adverse associations between MeHg exposure and developmental outcomes. These findings suggest that higher fish consumption, resulting in higher maternal (n-3) PUFA status, during pregnancy is associated with beneficial developmental effects rather than detrimental effects resulting from the higher concomitant exposures of the fetus to MeHg. The association of maternal (n-3) PUFA status with improved child language development may partially explain the authors' previous finding of improving language scores, as prenatal MeHg exposure increased in an earlier mother-child cohort in the Seychelles where maternal PUFA status was not measured.
Poorer socioeconomic conditions early in life have been linked with memory, attention and learning deficits in adulthood, as well as with specific areas of educational achievement. It remains unclear, however, whether these distal associations are mediated by more current socioeconomic factors. In this study, we sought to confirm the relation between early-life socioeconomic position (SEP) and adult cognitive function, and to examine potential mediation by contemporaneous SEP.
Data from 463 young adults from the Main Cohort of the Seychelles Child Development Study were analyzed using subtests of the Cambridge Neurological Test Automated Battery and the Woodcock Johnson Test of Scholastic Achievement in relation to maternal Hollingshead Social Status Index scores at study enrollment (infancy), follow-up at 107 months, and follow-up at 17 years.
Findings include evidence of a link between infant-period SEP and 17-year memory, which was not mediated by childhood and 17-year SEP. Verbal and mathematical achievement at 17 years was associated with SEP at all points in the life course.
SEP at different points during the young-adult life course may affect different cognitive domains later in life, which may provide targets for societal investment in ensuring adequate family resources throughout childhood and adolescence.
The relationship between blood pressure (BP) and cognitive outcomes in elderly adults has implications for global health care. Both hypertension and hypotension affect brain perfusion and worsen cognitive outcomes. The presence of hypertension and other vascular risk factors has been associated with decreased performance in executive function and attention tests. Cerebrovascular reserve has emerged as a potential biomarker for monitoring pressure-perfusion-cognition relationships. A decline in vascular reserve capacity can lead to impaired neurovascular coupling and decreased cognitive ability. Endothelial dysfunction, microvascular disease, and mascrovascular disease in midlife could also have an important role in the manifestations and severity of multiple medical conditions underlying cognitive decline late in life. However, questions remain about the role of antihypertensive therapies for long-term prevention of cognitive decline. In this Review, we address the underlying pathophysiology and the existing evidence supporting the role of vascular factors in late-life cognitive decline.
Essential hypertension is a chronic disorder having many potential physical and behavioral sequelae. This article evaluates the impact of hypertension on neuropsychological test performance. First, cross-sectional and longitudinal studies that examine the neuropsychological correlates of hypertension are reviewed. In general, hypertensives are found to perform more poorly than normotensives, particularly on tests of memory, attention, and abstract reasoning, and less consistently on tests of perception, constructional ability, mental flexibility, and psychomotor speed. Next, the influence of variables that may moderate relationships between hypertension and neuropsychological performance--such as age, education, and medication usage--are examined. Finally, potential mechanisms, both physiological and psychological, underlying associations between hypertension and neuropsychological performance are discussed.
To determine if NIDDM and blood pressure are risk factors for poor cognitive performance and if history and duration of NIDDM and blood pressure interact such that the risk of poor performance is greater for subjects with both NIDDM and hypertension.
We used a large prospective cohort sample with 187 NIDDM subjects and 1,624 nondiabetic subjects who were followed for 28-30 years. Cognitive function was assessed using eight tests of learning, memory, visual organization, verbal fluency attention, concept formation, and abstract reasoning. A composite score was also calculated. Odds ratios were used to estimate the relative risk of performing below the lower 25th percentile of z scores on these tests.
NIDDM and blood pressure interacted such that diagnosis and duration of NIDDM were associated with greater risk of poor performance on tests of visual memory and on the composite score for hypertensive subjects. Duration of NIDDM was associated with increased risk for poor performance on tests of verbal memory and concept formation. Insulin-treated NIDDM subjects were at higher risk for poor cognitive performance than those NIDDM subjects treated with oral agents or diet. Blood pressure level was associated independently with a measure of verbal fluency.
History and duration of NIDDM and high blood pressure are significant risk factors for poor cognitive performance. Hypertensive people with NIDDM are at greatest risk for poor performance on tests measuring visual organization and memory.
Cerebral white matter lesions are frequently observed on magnetic resonance imaging (MRI) scans in elderly people and are associated with stroke and dementia. Elevated blood pressure is presumed one of the main risk factors, although data are almost exclusively derived from cross-sectional studies. We assessed in 10 European cohorts the relation between concurrently and previously measured blood pressure levels, hypertension, its treatment, and severe cerebral white matter lesions. In total, 1805 nondemented subjects aged 65 to 75 years were sampled from ongoing community-based studies that were initiated 5 to 20 years before the MRI. White matter lesions in the periventricular and subcortical region were rated separately using semiquantitative measures. We performed logistic regression analyses adjusted for potential confounders in 1625 people with complete data. Concurrently and formerly assessed diastolic and systolic blood pressure levels were positively associated with severe white matter lesions. Both increases and decreases in diastolic blood pressure were associated with more severe periventricular white matter lesions. Increase in systolic blood pressure levels was associated with more severe periventricular and subcortical white matter lesions. People with poorly controlled hypertension had a higher risk of severe white matter lesions than those without hypertension, or those with controlled or untreated hypertension. Higher blood pressure was associated with an increased risk of severe white matter lesions. Successful treatment of hypertension may reduce this risk; however, a potential negative effect of decreasing diastolic blood pressure level on the occurrence of severe periventricular white matter lesions should be taken into account.
Objective.
—To assess the long-term relationship of midlife blood pressure levels to late-life cognitive function.Design.
—The 4678 surviving cohort members of the prospective Honolulu Heart Program (baseline, 1965-1968) were examined a fourth time in 1991 through 1993 and given a cognitive test.Participants.
—The subjects were 3735 Japanese-American men living in Hawaii in the community or in institutions, with an average age of 78 years at the fourth examination.Main Outcome Measures.
—Cognitive function, measured by the 100-point Cognitive Abilities Screening Instrument (CASI), was categorized into good (reference: a CASI score of 92 to 100), intermediate (<92 to 82), and poor (<82). Midlife systolic blood pressure (SBP) and diastolic blood pressure (DBP) values were measured in 1965,1968, and 1971. A respondent was classified into the following categories if two of three measurements fell into the following groups: for SBP, <110, 110 to 139, 140 to 159, and ≥160 mm Hg; and for DBP, <80, 80 to 89, 90 to 94, and ≥95 mm Hg.Results.
—When we controlled for age and education, the risk for intermediate and poor cognitive function increased progressively with increasing level of midlife SBP category (P for trend <.03 and <.001, respectively). For every 10—mm Hg increase in SBP there was an increase in risk for intermediate cognitive function of 7% (95% confidence interval [CI], 3% to 11%) and for poor cognitive function of 9% (95% CI, 3% to 16%). Adjustment for prevalent stroke, coronary heart disease, and subclinical atherosclerosis reduced the strength of the relationship between midlife SBP and poor cognitive function to 5% (95% CI, 0% to 12%). The level of cognitive function was not associated with midlife DBP.Conclusions.
—Midlife SBP is a significant predictor of reduced cognitive function in later life. Early control of SBP levels may reduce the risk for cognitive impairment in old age.(JAMA. 1995;274:1846-1851)
Our objective is to characterize the development of the literature on hypertension and cognitive functioning from a historical perspective. This goal was stimulated by the review on “Historical Trends and Milestones in Hypertension Research” in the October 2012 issue of Hypertension. Our specific aims are threefold: (1) to trace and describe the history of this area of research; (2) to identify milestones in knowledge and methods; and (3) to discuss briefly how this literature translates into patient care. The topic is of major relevance to research and practice because hypertension is a well-known risk factor for decline in cognitive performance within the normal range of cognitive functioning, mild cognitive impairment (MCI) and dementia. It is important to emphasize 3 features of the review: (1) it is not designed as a critical review of the literature, but rather to describe the historical influences on our current knowledge base (poor, mediocre and outstanding papers from the past have all shaped our present); (2) word-count limitations require that we omit statistical detail except to emphasize effect sizes in pivotal papers; and (3) each milestone topic is addressed by noting the earliest work then followed by examples of papers representing pivotal events. A number of comprehensive re- views of this literature are available, including a seminal paper summarizing the formative years of this research. Please see http://hyper.ahajournals.org for citations to additional reviews of the literature and papers published in Hypertension. We recognize the importance of the emerging literature on hypotension and cognitive function, but refer the readers to previous reviews which include this topic.
Introduction:
People worldwide depend upon daily fish consumption as a major source of protein and other nutrients. Fish are high in nutrients essential for normal brain development, but they also contain methylmercury (MeHg), a neurotoxicant. Our studies in a population consuming fish daily have indicated no consistent pattern of adverse associations between prenatal MeHg and children's development. For some endpoints we found performance improved with increasing prenatal exposure to MeHg. Follow up studies indicate this association is related to the beneficial nutrients present in fish.
Objectives:
To determine if the absence of adverse outcomes and the presence of beneficial associations between prenatal MeHg and developmental outcomes previously reported persists into adolescence.
Methods:
This study was conducted on the Main Cohort of the Seychelles Child Development Study (SCDS). We examined the association between prenatal MeHg exposure and subjects' performance at 17 years of age on 27 endpoints. The test battery included the Wisconsin Card Sorting Test (WCST), the California Verbal Learning Test (CVLT), the Woodcock-Johnson (W-J-II) Achievement Test, subtests of the Cambridge Neuropsychological Test Automated Battery (CANTAB), and measures of problematic behaviors. Analyses for all endpoints were adjusted for postnatal MeHg, sex, socioeconomic status, maternal IQ, and child's age at testing and the child's IQ was added for problematic behavioral endpoints.
Results:
Mean prenatal MeHg exposure was 6.9 ppm. There was no association between prenatal MeHg and 21 endpoints. Increasing prenatal MeHg was associated with better scores on four endpoints (higher W-J-II math calculation scores, reduced numbers of trials on the Intra-Extradimensional Shift Set of the CANTAB), fewer reports of substance use and incidents of and referrals for problematic behaviors in school. Increasing prenatal MeHg was adversely associated with one level of referrals to a school counselor.
Conclusions:
At age 17 years there was no consistent pattern of adverse associations present between prenatal MeHg exposure and detailed domain specific neurocognitive and behavioral testing. There continues to be evidence of improved performance on some endpoints as prenatal MeHg exposure increases in the range studied, a finding that appears to reflect the role of beneficial nutrients present in fish as demonstrated previously in younger subjects. These findings suggest that ocean fish consumption during pregnancy is important for the health and development of children and that the benefits are long lasting.
We assessed the association between birth weight, weight change, and current blood pressure (BP) across the entire age-span of childhood and adolescence in large school-based cohorts in the Seychelles, an island state in the African region.
Three cohorts were analyzed: 1004 children examined at age 5.5 and 9.1 years, 1886 children at 9.1 and 12.5, and 1575 children at 12.5 and 15.5, respectively. Birth and 1-year anthropometric data were gathered from medical files. The outcome was BP at age 5.5, 9.1, 12.5 or 15.5 years, respectively. Conditional linear regression analysis was used to estimate the relative contribution of changes in weight (expressed in z-score) during different age periods on BP. All analyses were adjusted for height.
At all ages, current BP was strongly associated with current weight. Birth weight was not significantly associated with current BP. Upon adjustment for current weight, the association between birth weight and current BP tended to become negative. Conditional linear regression analyses indicated that changes in weight during successive age periods since birth contributed substantially to current BP at all ages. The strength of the association between weight change and current BP increased throughout successive age periods.
Weight changes during any age period since birth have substantial impact on BP during childhood and adolescence, with BP being more responsive to recent than earlier weight changes.
To examine the relationship between baseline hypertension, blood pressure, and the development of cognitive decline in participants in the Women's Health Initiative Memory Study (WHIMS).
Prospective analyses.
Thirty-nine centers.
Seven thousand one hundred forty-nine women aged 65 and older.
The Modified Mini-Mental State Examination (3MS) was used to assess global cognitive functioning. Participants who scored below pre-established cutpoints were scheduled for more-extensive neurocognitive assessments. Results from these assessments were centrally adjudicated.
The mean age of this group of 7,149 participants at baseline was 71.0 +/- 3.8, and the mean 3MS score was 95.2 +/- 4.3. During a mean follow-up period of 4.5 years, women without hypertension tended to have slightly higher 3MS scores than women with hypertension (P=.001), but the difference was not seen after adjustment for covariates (P=.17). Women with hypertension also appeared to be at greater risk for probable dementia or mild cognitive impairment (MCI) (hazard ratio=1.35, 95% confidence interval=1.07-1.70, P=.01), although when potential cofounders were accounted for, this association was no longer significant (P=.06).
Hypertension and high blood pressure at baseline were not independently associated with MCI or probable dementia over time in older, cognitively intact, postmenopausal women enrolled in WHIMS after other potential confounders were taken into account. These analyses should not be viewed as discouraging appropriate medical treatment for hypertension.
In contrast to the large number of studies relating high blood pressure to morbidity and mortality in adulthood, relatively few studies evaluating outcomes of children with hypertension have been conducted. Results of recent studies evaluating hypertensive target-organ injury in childhood suggest that early abnormalities, including left ventricular hypertrophy, glomerular hyperfiltration, and retinopathy, occur more commonly than had formerly been believed, and in children with mild elevations of blood pressure. Ambulatory blood pressure monitoring may be an important tool for use in evaluating hypertensive target organ damage in children and adolescents.
Little is known about the role of microinfarcts in dementia and cognition. We examined microinfarcts and dementia, global cognition, and 5 cognitive systems in community-dwelling older persons.
Four hundred twenty-five subjects enrolled in the Religious Orders Study underwent annual clinical evaluations, including 19 neuropsychological tests and assessment for dementia, and brain autopsy (39% men; mean age at death, 87; Mini-Mental State Examination score, 21). Neuropathologic examination documented the presence, number, and location of chronic microinfarcts on 6-μm hematoxylin-eosin-stained sections from cortical and subcortical regions. Multiple regression analyses adjusted for age at death, sex, education, macroscopic infarcts, Alzheimer disease pathology, and Lewy bodies.
Microinfarcts were present in 129 of 425 (30%) persons (54 cortical, 80 subcortical, 49 multiple); 58 of 129 (45%) of persons with microinfarcts did not exhibit macroscopic infarcts. Persons with microinfarcts had increased odds of dementia (OR, 1.77; 95% CI, 1.07-2.92), especially those persons with multiple cortical microinfarcts. Microinfarcts were also associated with lower average global cognition (estimate, -0.287; SE, 0.113; P=0.012), particularly for persons with multiple cortical microinfarcts. Microinfarcts were specifically associated with lower episodic memory (estimate, -0.279; SE, 0.138; P=0.044), semantic memory (estimate, -0.391; SE, 0.130; P=0.003), and perceptual speed (estimate, -0.400; SE, 0.117; P<0.001). In addition, single, multiple, and cortical microinfarcts were associated with worse semantic memory and perceptual speed (all P<0.028). Neither macroscopic infarcts nor AD pathology modified these associations (all P>0.154).
Microinfarcts are common, and persons with multiple cortical microinfarcts have higher odds of dementia. Microinfarcts are also associated with lower cognition, specifically perceptual speed and semantic and episodic memory.
To the Editor:
Hypertension at middle age is a risk factor for vascular and neurodegenerative dementia later in life.1 Because populations are aging, the number of demented patients will grow 2-fold every 20 years, from 24.3 million people in 2000 to 81.1 million by 2040, with >60% living in developing countries.2 The question of whether hypertension is a modifiable risk factor for dementia is therefore of great clinical importance. Our 2007 meta-analysis1 included 4 placebo-controlled trials of blood pressure–lowering therapies for prevention of dementia (18 196 patients and 642 dementia cases).3,–,6 The common odds ratio was 0.89 (CI, 0.75 to 1.04) and did not reach statistical significance ( P =0.15). However, sensitivity analyses revealed a difference ( P =0.04) that depended on whether active treatment started with or included a diuretic or dihydropyridine calcium channel blocker compared with an inhibitor of the renin system. The pooled …
The objective was to determine whether children with sustained primary hypertension are at increased risk for learning disabilities (LDs), as a school-related manifestation of neurocognitive problems.
A total of 201 children 10 to 18 years of age who were referred because of elevated blood pressure (BP) were included. Patients were categorized as having or not having hypertension, on the basis of BP evaluation at the initial hypertension clinic visit and subsequent confirmation of sustained elevated BP outside the clinic setting. Parents reported whether their child had a provider-confirmed LD or attention-deficit/hyperactivity disorder (ADHD).
A total of 101 children without hypertension and 100 children with hypertension were evaluated; 18% of the children (n = 37) had LDs. In comparison with children without hypertension, children with hypertension were significantly more likely to have LDs (18% vs 9%; P < .001), irrespective of comorbid ADHD. With adjustment for demographic variables and obesity, the odds of having LDs were elevated for subjects with hypertension, in comparison with subjects without hypertension (odds ratio: 4.1 [95% confidence interval: 1.8-9.4]).
The rate of LDs, with or without ADHD treatment, was significantly higher for children with sustained primary hypertension, compared with children without hypertension. These findings add to the growing evidence for an association between primary hypertension and cognitive function and may inform treatment and monitoring decisions for these children who may be at risk for learning problems.
The prevalence of hypertension in children is increasing but its neurological effects are under-recognised. Here, we describe acute and chronic effects of childhood hypertension on the nervous system. Acute neurological involvement ranges from posterior reversible encephalopathy syndrome to, possibly, infarction and haemorrhage. Children with chronic hypertension are likely to have learning disabilities and deficiencies in executive function, which are potentially reversible with antihypertensive treatment. These cognitive defects may be secondary to abnormal regulation of cerebral blood flow. Raised blood pressure in childhood could also contribute to the early development of atherosclerosis, which can have both short-term and long-term adverse effects on vasculature. Clinical studies are needed to better define the full clinical range of paediatric hypertension on a child's nervous system. Furthermore, accurate biomarkers to define cognitive abnormalities and cerebral involvement need to be identified.
Hypertension is an established risk factor for dementia. However, the association between blood pressure and cognition in the very old is not fully determined and important to study considering the ageing population and the morbidity associated with cognitive impairment.
This cross-sectional study included 575 individuals aged 85, 90 or 95 years and above and living in northern Sweden or Finland. Participants were interviewed and assessed using a structured protocol. Systolic (SBP) and diastolic blood pressures (DBP) were measured and pulse pressure (PP) calculated. Cognitive function was evaluated using the Mini-Mental State Examination (MMSE). Data were also collected from medical charts and caregivers.
After adjustment for several demographic variables and diagnoses, SBP was significantly associated with MMSE in a nonlinear fashion; both high and low pressures were associated with poorer results. There was also a linear and positive association between PP and MMSE scores, but no association with DBP was found. Participants with dementia had lower blood pressure.
After adjustment for a number of health factors, there was an association between low blood pressure and cognitive impairment. The direction of any causal relationship between blood pressure and cognition remains to be determined.
We evaluated the cross-sectional relationship of blood pressure (BP) components with cognitive impairment after adjusting for potential confounders.
Reasons for Geographic and Racial Differences in Stroke (REGARDS) is a national, longitudinal population cohort evaluating stroke risk in 30,228 black and white men and women >or=45 years old. During the in-home visit, BP measurements were taken as the average of 2 measurements using a standard aneroid sphygmomanometer. Excluding participants with prior stroke or TIA, the present analysis included 19,836 participants (enrolled from December 2003 to March 2007) with complete baseline physical and cognitive evaluations. Incremental logistic models examined baseline relationships between BP components (systolic blood pressure [SBP], diastolic blood pressure [DBP], and pulse pressure [PP]) and impaired cognitive status (score of <or=4 on 6-Item Screener) after adjusting for demographic and environmental characteristics, cardiovascular risk factors, depressive symptoms, and current use of any antihypertensive medication.
Higher DBP levels were associated with impaired cognitive status after adjusting for demographic and environmental characteristics, risk factors, depressive symptoms, and antihypertensive medications. An increment of 10 mm Hg in DBP was associated with a 7% (95% confidence interval [CI] 1%-14%, p = 0.0275) higher odds of cognitive impairment. No independent association was identified between impaired cognitive status and SBP (odds ratio [OR] 1.02, 95% CI 0.99-1.06) or PP (OR 0.99, 95% CI 0.95-1.04). There was no evidence of nonlinear relationships between any of the BP components and impaired cognitive status. There was no interaction between age and the relationship of impaired cognitive status with SBP (p = 0.827), DBP (p = 0.133), or PP (p = 0.827) levels.
Higher diastolic blood pressure was cross-sectionally and independently associated with impaired cognitive status in this large, geographically dispersed, race- and sex-balanced sample of stroke-free individuals.
Strokes, vascular risk factors, and apolipoprotein E (APOE) genotype are associated with cognitive decline in the elderly, but definitive evidence that these affect cognition as early as middle age is limited.
We describe the relationships of APOE genotype, stroke, and vascular risk factors with cognitive change over a 14-year follow-up in the Atherosclerosis Risk in Communities (ARIC) Study cohort recruited while in middle age.
Participants included a subset of the ARIC Study who underwent assessments of cognitive function and vascular risk factors. Four cognitive assessments were performed between 1990-1992 and 2004-2006. Cognitive assessments included the Delayed Word Recall (DWR) Test, the Digit Symbol Substitution (DSS) Test, and the Word Fluency (WF) Test. Vascular risk factors were assessed during the baseline visit in 1990-1992. Incident stroke was recorded over the 14 years of follow-up.
There were 1130 participants (mean age, 59 +/- 4.3 [SD] years; 62% women; 52% African-American) with longitudinal data. In multivariate, random-effects linear models adjusted for age, education, gender, and race, the risk factors diabetes and APOE epsilon4 genotype were independently associated with a decline in performance on the DSS test (both P < .005), whereas hypertension and stroke were not. For DWR, stroke and APOE epsilon4 genotype were independent predictors of decline (both P < .001). For the WF test, metabolic syndrome, hypertension, and stroke were independently associated with decline (all P < .005). No evidence of differential effects of risk factors on cognitive decline by race, gender, or interactions between risk factors was found.
The vascular risk factors diabetes and hypertension, a history of stroke itself, and APOE epsilon4 genotype independently contribute to cognitive decline in late middle age and early elderly years.
To determine the relations between hypertension and parental ratings of behavior and executive functions in children with primary hypertension and to examine the potential moderating influence of obesity.
Hypertensive and normotensive control groups were matched for age, sex, race, intelligence quotient, maternal education, household income, and obesity. Parents completed the Child Behavior Checklist to assess Internalizing and Externalizing problems and the Behavior Rating Inventory of Executive Function to assess behavioral correlates of executive function.
Thirty-two hypertensive subjects and 32 normotensive control subjects (aged 10 to 18 years) were enrolled. On the Child Behavior Checklist, hypertensives had higher Internalizing T-scores (53 vs 44.5, P = .02) with 37% falling within the clinically significant range vs 6% of control subjects (P = .005). Internalizing score increased with increasing body mass index percentile in hypertensive but not normotensive subjects. Hypertensives had worse Behavior Rating Inventory of Executive Function Global Executive Composite T-scores compared with control subjects (50 vs 43, P = .009).
Children with both hypertension and obesity demonstrate higher rates of clinically significant internalizing problems, and hypertensives (irrespective of obesity) demonstrate lower parental ratings of executive function compared with normotensive control subjects.
The effects of alcohol on the availability of oxygen within the uterine lumen of rats were determined on Day 4 of pseudopregnancy. Intraluminal oxygen tension (pO2) was measured in vivo in anesthetized rats using a 22-gauge polarographic oxygen sensor. Intrauterine pO2 was measured for 15 min before and after intravenous injection of alcohol (1.0 g/kg: 100% ethanol/saline, 1:2v/v) or vehicle (physiological saline). Alcohol administration increased mean intrauterine pO2 (mm Hg) from a pretreatment level of 28.3 +/- 2.8 to 38.7 +/- 3.8 mm Hg (p less than 0.05, n = 10) at 15 min postinjection. The rapid rise in oxygen tension was accompanied by increased frequency of fluctuation (peaks/hr) in intraluminal pO2 (prealcohol: 64.2 +/- 8.8 vs. postalcohol 96.0 +/- 7.7 peaks/hr; (p less than 0.05, n = 10). Injection of saline did not alter any aspect of intrauterine pO2. During the period of measurement of luminal pO2, blood alcohol levels increased from 0 during pretreatment to 106 mg% within 10 min of injection. These results indicate that alcohol increases the availability of oxygen within the uterus during the time of endometrial sensitivity to deciduogenic stimuli and blastocyst implantation.
It was shown in a prior study that mildly hypertensive patients performed significantly less effectively on several sensory-perceptual, cognitive, and psychomotor tests than did matched normotensive controls. To determine whether these deficits are attributable to elevated blood pressure per se, hypertensive and control subjects were recalled for reexamination 15 months after the original tests. Results indicated that those hypertensives in whom blood pressure had been lowered with antihypertensive drugs showed significant restoration of performance scores toward the levels of normotensive subjects. Hypertensives who had not received active treatment remained deficient as compared with controls. These results indicated that behavioral deficits in mild hypertension may be reversible consequences of the effects of elevated blood pressure on the central nervous system.
To assess the long-term relationship of midlife blood pressure levels to late-life cognitive function.
The 4678 surviving cohort members of the prospective Honolulu Heart Program (baseline, 1965-1968) were examined a fourth time in 1991 through 1993 and given a cognitive test.
The subjects were 3735 Japanese-American men living in Hawaii in the community or in institutions, with an average age of 78 years at the fourth examination.
Cognitive function, measured by the 100-point Cognitive Abilities Screening Instrument (CASI), was categorized into good (reference: a CASI score of 92 to 100), intermediate (< 92 to 82), and poor (< 82). Midlife systolic blood pressure (SBP) and diastolic blood pressure (DBP) values were measured in 1965, 1968, and 1971. A respondent was classified into the following categories if two of three measurements fell into the following groups: for SBP, < 110, 110 to 139, 140 to 159, and > or = 160 mm Hg; and for DBP, < 80, 80 to 89, 90 to 94, and > or = 95 mm Hg.
When we controlled for age and education, the risk for intermediate and poor cognitive function increased progressively with increasing level of midlife SBP category (P for trend < .03 and < .001, respectively). For every 10-mm Hg increase in SBP there was an increase in risk for intermediate cognitive function of 7% (95% confidence interval [CI], 3% to 11%) and for poor cognitive function of 9% (95% CI, 3% to 16%). Adjustment for prevalent stroke, coronary heart disease, and subclinical atherosclerosis reduced the strength of the relationship between midlife SBP and poor cognitive function to 5% (95% CI, 0% to 12%). The level of cognitive function was not associated with midlife DBP.
Midlife SBP is a significant predictor of reduced cognitive function in later life. Early control of SBP levels may reduce the risk for cognitive impairment in old age.
Cerebral white matter lesions are a common finding on MRI in elderly persons. We studied the prevalence of white matter lesions and their relation with classic cardiovascular risk factors, thrombogenic factors, and cognitive function in an age- and gender-stratified random sample from the general population that consisted of 111 subjects 65 to 84 years of age. Overall, 27% of subjects had white matter lesions. The prevalence and severity of lesions increased with age. A history of stroke or myocardial infarction, factor VIIc activity, and fibrinogen level were each significantly and independently associated with the presence of white matter lesions. Significant relations with blood pressure level, hypertension, and plasma cholesterol were present only for subjects aged 65 to 74 years. White matter lesions tended to be associated with lower scores on tests of cognitive function and were significantly associated with subjective mental decline. This study suggests that classic cardiovascular risk factors, as well as thrombogenic factors, are associated with white matter lesions in subjects over 65 years of age in the general population, and that these lesions may be related to cognitive function.
Since hypertension is a major risk factor for multi-infarct dementia, this study aimed to evaluate the effect of blood pressure on cognitive function in elderly subjects on no medication and disease-free.
A cross-sectional survey.
Community.
598 healthy community-resident subjects aged 70 years and over who were on no treatment.
Blood pressure (BP) and MMSE score, an index of cognitive function.
Mean age of the sample was 75.7 years, mean BP 160/86 mmHg, mean MMSE 28.0. Systolic BP correlated negatively with MMSE (P < 0.05), but diastolic BP showed no significant overall correlation. To study possible J-shaped curve effects of BP, the sample was stratified into three groups--low BP, normal BP, and high BP--at levels one standard deviation from the mean for both systolic and diastolic pressures. Mean MMSE scores for low, normal and high systolic BP were 28.3, 28.1, 27.5, respectively; for low, normal, and high diastolic BP scores were 28.0, 28.1, and 27.5 respectively. Multivariate analysis of variance found the differences between normal and high to be significant at P < 0.001 for systolic and P = 0.001 for diastolic BPs.
High blood pressure is associated with cognitive impairment in healthy, drug-free, older people.
Hypertension is associated with impaired cognition, but it is unclear whether this impairment is reversible. We sought to evaluate the effect of blood pressure reduction on cognition.
A randomized, double-blind trial.
A single center, with assessments in subjects' domiciles.
Community-screened subjects more than 69 years of age who had median diastolic pressures > 99 mm Hg and systolic pressures > 159 mm Hg or diastolic > 85 mm Hg and systolic > 179 mm Hg with Mini-Mental State Examination scores of 20 to 28. Subjects had not previously received antihypertensive treatment.
Captopril 12.5 mg twice daily or bendrofluazide 2.5 mg daily for 24 weeks, preceded by a 2-week placebo phase.
Cognition was evaluated by a psychometric test battery comprising Immediate and Delayed Logical Memory, Paired Associates recall, Raven's Progressive Matrices, Halstead Reitan Trail Making A, and the Anomalous Sentences Repetition Test.
Eighty-one subjects (28 male, 53 female) were treated (41 captopril, 40 bendrofluazide). At entry, mean age was 76.1 years (range 70-84), mean blood pressure was 191 (160-230) mm Hg systolic, 101 (88-110) mm Hg diastolic, and mean MMSE score 26.1. A total of 69 subjects completed the trial. The 25th, 50th, and 75th percentiles of the difference between pretreatment and Week 24 blood pressures wer 15 mm Hg, 35 mm Hg, and 50 mm Hg (systolic) and 5 mm Hg, 10 mm Hg, and 19 mm Hg (diastolic). There were no significant differences in any psychometric test between captopril and bendrofluazide. The 19 subjects in the quartile that lowered their diastolic blood pressure most ( > or = 19 mm Hg) had improved scores on Anomalous Sentences (P = .012) and Paired Associates (P = .044) compared to the 19 subjects in the least blood pressure responsive quartile (fall < or = 5 mm Hg)s.
The treatment of hypertension is not hazardous to cognitive function in older people with pre-existing cognitive impairment. Long-term adequate blood pressure control may reverse cognitive impairment associated with pre-existing hypertension.
Studies of outbreaks of methylmercury poisoning in Japan and Iraq from consumption of methylmercury (MeHg)-contaminated fish or bread proved that brain was the target organ, the toxic effects were dose-related, and the fetal brain was especially susceptible. Previous population studies suggested that a 5% risk of minimal fetal effect may be associated with a maternal hair mercury concentration during pregnancy of 10-20 ppm (mu g/g), a level that can be readily achieved by frequent consumers of fish. However, these studies had limitations, and as a result no definite conclusion concerning the lowest effect level could be reached and the question of a possible hazard to public health remained unanswered. There was a clear need for a more definitive study that would be prospective, involve a large enough cohort for risk analysis and adhere to accepted epidemiological principles. An appropriate site for such a study is the Republic of Seychelles, a location that afforded successful collaboration between the Seychelles Ministry of Health and faculty of the University of Rochester. A pilot study of 804 infant-mother pairs was followed by a main study of 779 mother-infant pairs. In the pilot study children were examined once between 5 and 109 weeks of age; in the main study they are being evaluated longitudinally starting at 6 1/2 months of age. This paper introduces both the pilot and main studies, describes their design, and summarizes the findings through 6 1/2 months of age. When the Seychelles study is completed, the analyses will provide a database for those nations that choose to regulate their citizens' fish consumption and/or provide dietary education.
White matter lesions (WMLs) detected by cerebral magnetic resonance imaging (MRI) are putatively a consequence of cerebral hypoperfusion or ischemia. We investigated the prevalence, severity and correlates of WMLs in a population-based sample of 1,920 African-American and European-American men and women aged 55-72 years, during the second follow-up examination of the Atherosclerosis Risk in Communities Study. The spin density images from 1.5-tesla MRI scans were used to define WMLs using a 0-9 scale with 0 for normal and 9 for most severe WMLs. Age was positively associated with the prevalence (percent) and severity of WMLs. African-Americans had lower overall prevalence of WMLs, but a higher prevalence of relatively more severe WMLs, than European-Americans. After adjusting for age, sex, and ethnicity, WMLs were significantly associated with smoking, lower education, hypertension, systolic blood pressure, and pulse pressure, and weakly associated with diastolic blood pressure. The associations of smoking, alcohol intake, systolic and diastolic blood pressure, pulse, pressure, and hypertension were stronger in African-Americans than in European-Americans (p < 0.15 for interactions by ethnicity). This population-based MRI study documents significant relationships between several cardiovascular disease risk factors and WMLs. The findings suggest that such factors play a role in the pathogenesis of WMLs, an elements linked to hypoperfusion and/or fluid accumulation, which presumably lead to WMLs. African-Americans exhibited both a higher proportion of normal white matter and a higher proportion of relatively more severe WMLs than European-Americans.
To determine the extent to which individual changes in systolic blood pressure (SBP) over a 30-year interval are associated with differential neuropsychological outcomes in old age.
Seven hundred seventeen survivors from the Western Collaborative Group Study, a longitudinal study of cardiovascular risk factors now in its 38th year of follow-up, with blood pressures measured in middle age (mean=45 years) and in old age (mean=75 years) and neuropsychological tests administered at follow-up were included in this analysis. Participants were grouped according to 30-year change in SBP (increased, decreased, or "normal"). Analyses focused on comparisons of neuropsychological performance of "high SBP trackers" (ie, those with persistent SBP>/=140 mm Hg throughout adult life) and of SBP "decreasers" with the performance of those whose SBP was either stable or changed in an expected way over time.
Only 7.5% of participants had elevated SBP in middle age, but 43.8% of participants had elevated SBP in old age. After adjustment for age, education, depression, clinically defined stroke, and use of antihypertensive medications and after exclusion of individuals with impaired cognitive performance at follow-up, high SBP trackers, 5.0% (n=36), performed consistently less well than the "normal" SBP subgroups on a composite measure of verbal learning and memory (P=0.04). When compared with the "normal" SBP subgroup, the SBP decreasers, 5.3% (n=38), performed less well on speeded performance (P=0.03).
There is a relatively small group of people who maintain elevated SBP throughout their adult lives. These persons are at increased risk for reduced verbal learning and memory function. There is also a group of individuals who experience a decrease in SBP and who are at risk for decreased psychomotor speed. Delineation of these 2 SBP subgroups may lead to further clarification of the effects of SBP on neurobehavioral function in older adults.
To determine whether there are racial/ethnic differences regarding the relationship of level of blood pressure to change in cognitive function in older people.
Longitudinal data 1986 to 1989 on representative, older, community-residing African Americans and whites. Blood pressure levels were assessed and a brief screen of cognitive functioning, the Short Portable Mental Status Questionnaire (SPMSQ), was performed at baseline and 3 years later.
Five contiguous counties in the Piedmont area of North Carolina.
African-American (n = 2,260) and white(n = 1,876) participants in the Duke Established Populations for Epidemiologic Studies of the Elderly, aged 65 to 105 at baseline.
The outcome measure was change in SPMSQ score over 3 years. Covariates included age; education; gender; self-reported diabetes mellitus, stroke, heart attack, current smoking, and depressive symptomatology;and use of antihypertensive medication. The primary independent variable was measured blood pressure.
In unadjusted analyses, a statistically significant U-shaped relationship was found between systolic (but not diastolic) blood pressure levels and change in SPMSQ score over a 3-year period for older white men and women. No such relationships were found between these blood pressure measurements and change in SPMSQ score in older African Americans. These findings remained after adjustment for initial SPMSQ score, demographic characteristics, and use of antihypertensive medication. There were no significant interactions between race and blood pressure on change in cognitive function.
Decline in cognitive function was associated with extremes of systolic blood pressure in older white people. Although a similar but muted nonsignificant association was found in older African Americans, the curves for the two groups were not significantly different. Further studies in older African Americans are needed.
Accumulating evidence supports a causal role of hypertension for cognitive decline above and beyond its relationship to frank stroke. Hypertension-associated pathologic changes in the brain and its vasculature include vascular remodeling, impaired cerebral autoregulation, cerebral microbleeds, white matter lesions, unrecognized lacunar infarcts, and Alzheimer-like changes such as amyloid angiopathy and cerebral atrophy. White matter lesions and retinal vascular changes, both of which can be imaged noninvasively, may reveal the general condition of the cerebral vasculature or the presence of arteriosclerotic or hypertensive encephalopathy. These noninvasive indicators may also identify a subgroup in whom infarct prevention, particularly via blood pressure reduction, is of paramount importance. Optimal control of blood pressure on a population-wide basis, but particularly in those prone to cognitive loss, is thus a critically important but as yet elusive goal that should be fully exploited for its potential to reduce future cognitive impairment.
Exposure to methylmercury (MeHg) before birth can adversely affect children's neurodevelopment. The most common form of prenatal exposure is maternal fish consumption, but whether such exposure harms the fetus is unknown. We aimed to identify adverse neurodevelopmental effects in a fish-consuming population.
We investigated 779 mother-infant pairs residing in the Republic of Seychelles. Mothers reported consuming fish on average 12 meals per week. Fish in Seychelles contain much the same concentrations of MeHg as commercial ocean fish elsewhere. Prenatal MeHg exposure was determined from maternal hair growing during pregnancy. We assessed neurocognitive, language, memory, motor, perceptual-motor, and behavioural functions in children at age 9 years. The association between prenatal MeHg exposure and the primary endpoints was investigated with multiple linear regression with adjustment for covariates that affect child development.
Mean prenatal MeHg exposure was 6.9 parts per million (SD 4.5 ppm). Only two endpoints were associated with prenatal MeHg exposure. Increased exposure was associated with decreased performance in the grooved pegboard using the non-dominant hand in males and improved scores in the hyperactivity index of the Conner's teacher rating scale. Covariates affecting child development were appropriately associated with endpoints.
These data do not support the hypothesis that there is a neurodevelopmental risk from prenatal MeHg exposure resulting solely from ocean fish consumption.
Computers have been used for a number of years in neuropsychological assessment to facilitate the scoring, interpretation, and administration of a variety of commonly used tests. There has been recent interest in applying computerized technology to pediatric neuropsychological assessment, which poses unique demands based on the need to interpret performance relative to the child's developmental level.
However, pediatric neuropsychologists have tended to implement computers in the scoring, but not administration, of tests. This trend is changing based on the work of experimental neuropsychologists who frequently combine data obtained from test batteries with lesion or neuroimaging data allowing descriptions of brain-behavior relations to be made with increasing confidence. One such battery is the Cambridge Neuropsychological Testing Automated Battery (CANTAB), and current studies in which the CANTAB has been used to measure executive functions in children are reviewed.
Computerized batteries of this type can record aspects of performance that are difficult for psychometrists to achieve, and these may reflect activity in developing neural networks with more sensitivity than can be achieved with traditional tests. However, before computerized test administration becomes a routine part of pediatric neuropsychological assessment, several obstacles must be overcome. Despite these limitations, it is concluded that computerized assessment can improve the field by facilitating the collection of normative and clinical data.
Here we examined potential interactive relations of hypertension and gender to cognitive function in 98 healthy, older adults (ages 55-83 years; 64% male; 92% White). After statistical adjustment for age and education, hypertensives performed significantly more poorly than normotensives on tests of motor speed and manual dexterity (p < 0.05). The adverse consequences of hypertension in older adults was more pronounced for female than male hypertensives on tests of delayed visual memory, visual attention and working memory, visuoconstructional ability, motor speed and manual dexterity for the non-dominant hand (p < 0.05); these are dimensions of performance for which female gender may be a relative disadvantage. The findings suggest the need to further examine subgroups that are vulnerable to the cognitive correlates of hypertension. The results also highlight the need for increased attention to blood pressure control in older adults for the preservation of cognitive function.
This investigation examined cross-sectional and longitudinal relations, both linear and nonlinear, of blood pressure (BP) and its interaction with demographic and lifestyle variables to a broad spectrum of cognitive functions. Eight hundred forty-seven participants (503 men and 344 women) from the Baltimore Longitudinal Study of Aging completed tests of verbal and nonverbal memory, attention, perceptuo-motor speed, executive functions, and confrontation naming, and clinical assessment of BP on 1 to 7 occasions over 11 years. Mixed-effects regression models, adjusted for age, education, gender, alcohol consumption, smoking status, depression scores, and use of antihypertensive medications, revealed nonlinear relations of systolic BP with longitudinal change on tests of nonverbal memory and confrontation naming; cognitive decline was apparent among older (80 years) individuals with higher systolic BP. Cross-sectional findings, across testing sessions, indicated moderated U- and J-shaped relations between BP and cognitive function. Both high and low diastolic BP were associated with poorer performance on tests of executive function and confrontation naming among less-educated persons; with tests of perceptuo-motor speed and confrontation naming among nonmedicated (antihypertensives) individuals; and with executive function among older individuals. Cross-sectional linear relations included higher systolic BP and poorer nonverbal memory in nondrinkers, and higher diastolic BP and poorer working memory among less-educated individuals. Results indicate that cross-sectional and longitudinal relations of BP to cognitive function are predominantly nonlinear and moderated by age, education, and antihypertensive medications. Careful monitoring and treatment of both high and low BP levels may be critical to the preservation of cognitive function.
The relationship between low blood pressure and cognitive function among younger individuals is not fully understood. While a number of studies have examined hypertensive and hypotensive individuals, particularly in older populations, little attention has been devoted to healthy, young populations. We tested 105 healthy young individuals whose blood pressure levels naturally fell in the below normal-to-normal range. Our primary finding was a positive relation between blood pressure and cognition, as measured by two visuospatial attention tasks. This relation appears to be specific to visuospatial skills, as no relationship was observed between recognition memory and blood pressure. We discuss possible explanations for this positive relationship, such as structural neural mechanisms, and how they apply to the overall blood pressure-cognition relationship.
Prenatal exposure to organic methylmercury (MeHg) from seafood consumption has been reported to increase children's blood pressure (BP). A report from the Faroe Islands noted significantly increased diastolic and systolic BP in 7-year-old children as prenatal MeHg exposure increased. The Faroese diet includes sea mammals that contain MeHg, cadmium, and other pollutants. We examined this relationship in the Seychelles Islands to determine if it was present in a society exposed primarily to MeHg from consuming ocean fish.
We obtained BP at ages 12 and 15 years on children with known prenatal MeHg exposure enrolled in the Seychelles Child Development Study (SCDS). We examined the association between prenatal MeHg exposure and BP using longitudinal models and linear regression adjusted for relevant covariates.
Blood pressure at both ages was associated with BMI, height and maternal hypertension during pregnancy as expected. No association between prenatal MeHg exposure and BP was present in girls at either age or in either sex at age 12 years. At age 15 years diastolic BP in boys increased with increasing prenatal MeHg exposure, while systolic BP was unaffected.
It is unclear whether the association between prenatal MeHg exposure and diastolic BP seen in 15-year-old boys is of biological significance or if it is a chance finding. However, the finding is intriguing and deserves further study.
To evaluate the relationship between elevated blood pressure (BP) and cognitive test performance in a nationally representative sample of children. Study design The National Health and Nutrition Examination Survey III provides cross-sectional data for children 6 to 16 years, including BP and cognitive test scores. Elevated BP was defined as systolic or diastolic BP >or=90th percentile. Cognitive tests were compared for children with elevated and normal BP. Linear regression was used to evaluate the relation between elevated BP and decreased test scores.
Among the 5077 children, 3.4% had systolic BP >or=90th percentile and 1.6% diastolic BP >or=90th percentile. Children with elevated systolic BP had lower average scores compared with normotensive children for digit span (7.9 vs 8.7, P=.01), block design (8.6 vs 9.5, P=.03), and mathematics (89.6 vs 93.8, P=.01). Elevated diastolic BP was associated with lower average scores on block design (9.5 vs 11, P=.01). Linear regression showed that elevated systolic BP was independently associated with lower digit span scores (P=.032).
Children with elevation of systolic BP are at risk for central nervous system end-organ damage, as manifested by decreased digit span test scores.
A large number of studies have examined the tracking of blood pressure (BP) from childhood to adulthood, but the reported findings are inconsistent and few systematic analyses have been conducted.
We conducted a systematic search of PubMed for studies that examined the tracking of BP from childhood to adulthood published between January 1970 and July 2006. From 301 retrieved papers, 50 cohort studies met our inclusion criteria and provided 617 data points (Pearson/Spearman correlation coefficients) for systolic BP (SBP) and 547 data points for diastolic BP (DBP) for our meta-analysis. Information on sample characteristics and BP measurement protocols was extracted. Fisher z transformation and random-effects meta-regression analysis were conducted. The reported BP tracking correlation coefficients varied from -0.12 to 0.80 for SBP and from -0.16 to 0.70 for DBP, with an average of 0.38 for SBP and 0.28 for DBP. BP tracking varied significantly by baseline age and length of follow-up. The strength of BP tracking increased with baseline age by 0.012 for SBP (P<0.001) and 0.009 for DBP (P<0.001) and decreased with follow-up length by 0.008 for SBP (P<0.001) and 0.005 for DBP (P<0.001). BP tracking did not vary markedly across the number of BP measurements or race/population groups.
Data from diverse populations show that the evidence for BP tracking from childhood into adulthood is strong. Childhood BP is associated with BP in later life, and early intervention is important.
Fish consumption during gestation can provide the fetus with long-chain polyunsaturated fatty acids (LCPUFA) and other nutrients essential for growth and development of the brain. However, fish consumption also exposes the fetus to the neurotoxicant, methyl mercury (MeHg). We studied the association between these fetal exposures and early child development in the Seychelles Child Development Nutrition Study (SCDNS). Specifically, we examined a priori models of Omega-3 and Omega-6 LCPUFA measures in maternal serum to test the hypothesis that these LCPUFA families before or after adjusting for prenatal MeHg exposure would reveal associations with child development assessed by the BSID-II at ages 9 and 30 months. There were 229 children with complete outcome and covariate data available for analysis. At 9 months, the PDI was positively associated with total Omega-3 LCPUFA and negatively associated with the ratio of Omega-6/Omega-3 LCPUFA. These associations were stronger in models adjusted for prenatal MeHg exposure. Secondary models suggested that the MeHg effect at 9 months varied by the ratio of Omega-6/Omega-3 LCPUFA. There were no significant associations between LCPUFA measures and the PDI at 30 months. There were significant adverse associations, however, between prenatal MeHg and the 30-month PDI when the LCPUFA measures were included in the regression analysis. The BSID-II mental developmental index (MDI) was not associated with any exposure variable. These data support the potential importance to child development of prenatal availability of Omega-3 LCPUFA present in fish and of LCPUFA in the overall diet. Furthermore, they indicate that the beneficial effects of LCPUFA can obscure the determination of adverse effects of prenatal MeHg exposure in longitudinal observational studies.
Fish contain nutrients that promote optimal brain growth and development but also contain methylmercury (MeHg) that can have toxic effects. The present study tested the hypothesis that the intake of selected nutrients in fish or measures of maternal nutritional status may represent important confounders when estimating the effects of prenatal methylmercury exposure on child development. The study took place in the Republic of Seychelles, an Indian Ocean archipelago where fish consumption is high. A longitudinal cohort study design was used. A total of 300 mothers were enrolled early in pregnancy. Nutrients considered to be important for brain development were measured during pregnancy along with prenatal MeHg exposure. The children were evaluated periodically to age 30 months. There were 229 children with complete outcome and covariate data for analysis. The primary endpoint was the Bayley Scales of Infant Development-II (BSID-II), administered at 9 and 30 months of age. Combinations of four secondary measures of infant cognition and memory were also given at 5, 9 and 25 months. Cohort mothers consumed an average of 537 g of fish (nine meals containing fish) per week. The average prenatal MeHg exposure was 5.9 ppm in maternal hair. The primary analysis examined the associations between MeHg, maternal nutritional measures and children's scores on the BSID-II and showed an adverse association between MeHg and the mean Psychomotor Developmental Index (PDI) score at 30 months. Secondary analyses of the association between the PDI and only MeHg alone or nutritional factors alone showed only a borderline significant association between MeHg and the PDI at 30 months and no associations with nutritional factors. One experimental measure at 5 months of age was positively associated with iodine status, but not prenatal MeHg exposure. These findings suggest a possible confounding role of maternal nutrition in studies examining associations between prenatal MeHg exposures and developmental outcomes in children.
Fish consumption and prenatal methylmercury exposure: cognitive and behavioral outcomes in the main cohort at 17 years from the Seychelles child development study Does prenatal methylmercury exposure from fish consumption affect blood pressure in childhood
- Pw Davidson
- Thurston Da Cory-Slechta
- Sw
- Ls Huang
- Cf Shamlaye
- D Gunzler
Davidson PW, Cory-Slechta DA, Thurston SW, Huang LS, Shamlaye CF, Gunzler D, et al. Fish consumption and prenatal methylmercury exposure: cognitive and behavioral outcomes in the main cohort at 17 years from the Seychelles child development study. Neurotoxicology 2011; 32:711–717. 17. Thurston SW, Bovet P, Myers GJ, Davidson PW, Georger LA, Shamlaye C, et al. Does prenatal methylmercury exposure from fish consumption affect blood pressure in childhood? Neurotoxicology 2007; 28:924–930.
Hypertension and cognitive function: pathophysiologic effects of hypertension on the brain. Current hypertension reports
- T A Manolio
- J Olson
- W T Longstreth
Manolio TA, Olson J, Longstreth WT. Hypertension and cognitive function: pathophysiologic
effects of hypertension on the brain. Current hypertension reports. 2003 Jun; 5(3):255-261.
[PubMed: 12724059]