[Show abstract][Hide abstract] ABSTRACT: Lower intelligence early in life is associated with increased risks for coronary heart disease (CHD) and mortality. Intelligence level might affect compliance to treatment but its prognostic importance in patients with CHD is unknown.
A cohort of 1923 Swedish men with a measure of intelligence from mandatory military conscription in 1969-1970 at age 18-20, who were diagnosed with CHD 1991-2007, were followed to the end of 2008. Primary outcome: recurrent CHD event. Secondary outcome: case fatality from the first event, cardiovascular and all-cause mortality. National registers provided information on CHD events, comorbidity, mortality and socioeconomic factors.
The fully adjusted HRs for recurrent CHD for medium and low intelligence, compared with high intelligence, were 0.98, (95% CIs 0.83 to 1.16) and 1.09 (0.89 to 1.34), respectively. The risks were increased for cardiovascular and all-cause mortality with lower intelligence, but were attenuated in the fully adjusted models (fully adjusted HRs for cardiovascular mortality 1.92 (0.94 to 3.94) and 1.98 (0.89 to 4.37), respectively; for all-cause mortality 1.63 (1.00 to 2.65) and 1.62 (0.94 to 2.78), respectively). There was no increased risk for case-fatality at the first event (fully adjusted ORs 1.06 (0.73 to 1.55) and 0.97 (0.62 to 1.50), respectively).
Although we found lower intelligence to be associated with increased mortality in middle-aged men with CHD, there was no evidence for its possible effect on recurrence in CHD.
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Journal of epidemiology and community health. 12/2014;
[Show abstract][Hide abstract] ABSTRACT: AimsSymptoms of anxiety and depression often co-exist with cardiovascular disease, yet little is known about the prospective risk for heart failure (HF) in people with symptoms of depression and anxiety. We aimed to study these prospective associations using self-reported symptoms of anxiety, depression, and mixed symptoms of anxiety and depression (MSAD) in a large population sample.Methods and resultsIn the second wave of the Nord-Trøndelag Health Study (HUNT 2, 1995–1997), Norway, baseline data on symptoms of anxiety and depression, socio-demographic variables, health status including cardiovascular risk factors, and common chronic somatic diseases were registered for 62 567 adults, men and women, free of known HF. The cohort was followed for incident HF from baseline throughout 2008. A total of 1499 cases of HF occurred during a mean follow-up of 11.3 years (SD = 2.9), identified either in hospital registers or by the National Cause of Death Registry. There was no excess risk for future HF associated with symptoms of anxiety or MSAD at baseline. For depression, the multi-adjusted hazard ratios for HF were 1.07 (0.87–1.30) for moderate symptoms and 1.41 (1.07–1.87) for severe symptoms (P for trend 0.026). Established cardiovascular risk factors, acute myocardial infarction (AMI) prior to baseline, and adjustment for incident AMI as a time-dependent covariate during follow-up had little influence on the estimates.Conclusion
Symptoms of depression, but not symptoms of anxiety or MSAD, were associated with increased risk for HF in a dose–response manner. The increased risk could not be fully explained by cardiovascular or socio-economic risk factors, or by co-morbid AMI.
European Journal of Heart Failure 07/2014; · 5.25 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Women with a history of preeclampsia are at increased lifetime risk for cardiovascular disease. Their offspring may carry similar risks. The aim was to study cardiovascular and metabolic risk factors 11 years after the delivery among women who were diagnosed with mild, moderate or severe preeclampsia, and their offspring, compared to women without preeclampsia and their offspring.
American journal of obstetrics and gynecology. 06/2014;
[Show abstract][Hide abstract] ABSTRACT: Cardiorespiratory fitness (CRF) is a strong predictor of future health, but measurements of CRF are time-consuming and involve costly test procedures. We assessed whether a simple, non-exercise based test of CRF predicted long-term all-cause and cardiovascular (CVD) mortality.
In this prospective cohort study we used a previously published non-exercise test to estimate CRF in healthy men (n=18,348) and women (n=18,764) from the first HUNT Study (1984-86) in Norway. We used Cox-regression to obtain hazard ratios (HR) for mortality during a mean follow-up of 24 years. Assessment of model validity was performed by standard procedures of discrimination and calibration.
CRF was inversely associated with all-cause and CVD mortality in men and women below 60 years of age at baseline after adjustment for confounders. For each metabolic equivalent (MET, ~3.5 mL[BULLET OPERATOR]kg[BULLET OPERATOR]min) higher CRF, HR for CVD mortality was 21% lower in both men (95% CI, 17-26%) and women (95% CI, 12-29%). HR for all-cause mortality was 15% (95% CI, 12-17%) lower in men and 8% (95% CI, 3-13%) lower in women for each MET higher CRF. The ability of the model to discriminate mortality risk among participants below 60 was better for CRF (AUC: 0.70-0.77) compared to each variable that constituted the model (AUC: 0.55-0.63) and an aggregated sum of z-scores for each variable (AUC: 0.61-0.65). Comparison of observed and predicted risk indicated good model calibration.
This method of assessing CRF is feasible and practically useful in primary care for identification of apparently healthy individuals at increased risk of premature cardiovascular disease and all-cause mortality.
Medicine and science in sports and exercise 02/2014; · 4.48 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We sought to investigate whether obesity in the absence of metabolic abnormalities might be a relatively benign condition in relation to acute myocardial infarction (AMI) and heart failure (HF).Background The results of previous studies are conflicting for AMI and largely unknown for HF, and the role of the duration of obesity has not been investigated.
In a population-based prospective cohort study, a total of 61,299 men and women free from cardiovascular disease were classified according to body-mass index (BMI) and metabolic status at baseline. BMI was also measured 10 and 30 years before baseline for 27,196 participants.
During 12 years of follow-up, 2,547 participants had a first AMI, and 1,201 a first HF. Compared to being normal weight (BMI>25) and metabolically healthy, the multivariable-adjusted hazard ratio (HR) for AMI was 1.1 (95% CI 0.9-1.4) among obese (BMI≥30) and metabolically healthy participants, and 2.0 (1.7-2.3) among obese and metabolically unhealthy. We found similar results for severe (BMI ≥35), long lasting (<30 years), and abdominal obesity stratified for metabolic status. For HF, the HRs associated with obesity were 1.7 (1.3-2.3) and 1.7 (1.4-2.2), for metabolically healthy and unhealthy participants, respectively. Severe and long lasting obesity were particularly harmful in relation to HF, regardless of metabolic status.
In relation to AMI, obesity without metabolic abnormalities did not confer substantial excess risk, not even for severe or long-lasting obesity. For HF, even metabolically healthy obesity was associated with increased risk, particularly for long lasting or severe obesity.
Journal of the American College of Cardiology 12/2013; · 14.09 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The nature of the association of depression and anxiety with risk for acute myocardial infarction (AMI) remains unclear. We aimed to study the prospective association of single and recurrent self-reported symptoms of anxiety and depression with a risk of AMI in a large Norwegian population based cohort.
In the second wave of the Nord-Trøndelag Health Study (HUNT2, 1995-97) baseline data on anxiety and depression symptoms, sociodemographic variables, health status including cardiovascular risk factors and common chronic disorders were registered for 57 953 adult men and women free of cardiovascular disease. The cohort was followed up during a mean (SD) 11.4 (2.9) years for a first AMI from baseline through 2008. A total of 2111 incident AMIs occurred, either identified at hospitals or by the National Cause of Death Registry. The multi-adjusted hazard ratios were 1.31 (95% CI 1.03-1.66) for symptoms of depression and 1.25 (CI 0.99-1.57) for anxiety. Two episodes of mixed symptoms of anxiety and depression (MSAD), reported 10 years apart, increased the risk for AMI by 52% (11-108%). After exclusion of the first 5 years of follow-up, the association of depression symptoms with AMI risk was attenuated. Relative risk for AMI with anxiety symptoms and MSAD weakened when participants with chronic disorders were excluded.
Self-reported symptoms of depression and anxiety, especially if recurrent, were moderately associated with the risk of incident AMI. We had some indications that these associations might partly reflect reverse causation or confounding from common chronic diseases.
European Heart Journal 09/2013; · 14.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background:Adult weight gain is associated with increased risk of postmenopausal breast cancer. Most previous studies are limited by using recalled or self-reported data, and it is not known if age-specific weight changes are important for breast cancer risk.Methods:In a Norwegian cohort of 28 153 women (and 900 incident breast cancers) with longitudinal anthropometric measurements over up to 30 years, we studied both overall and age-related weight changes in adulthood and risk of postmenopausal breast cancer.Results:Overall, weight gain in adulthood was associated with increased breast cancer risk (hazard ratio (HR) per kg per year 1.31, 95% confidence interval (CI) 1.11-1.54). Weight gain before (HR per kg per year 1.38, 95% CI 1.09-1.75) or around menopause (1.69, 95% CI 1.32-2.16) was associated with increased risk, but there was no clear risk increase associated with later weight gain (HR per kg per year 0.92, 95% CI 0.73-1.18).Conclusion:Weight gain in adulthood was associated with increased risk of breast cancer. Our results suggest that weight gain before and around menopausal age may be particularly important for breast cancer risk among postmenopausal women.British Journal of Cancer advance online publication, 23 July 2013; doi:10.1038/bjc.2013.403 www.bjcancer.com.
British Journal of Cancer 07/2013; · 5.08 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Endogenous estrogens prevent lipid peroxidation, which is pivotal in atherogenesis. Dyslipidemia may therefore be more dangerous for men than for women as a risk factor for acute myocardial infarction (AMI). A differential effect by sex has not been empirically established.
In a prospective population-based cohort study of 23,525 women and 20,725 men younger than 60 years of age at baseline, we followed participants for 12 years for a first AMI. By calculating the proportion of AMI among men with dyslipidemia attributable to the synergism between male sex and dyslipidemia, we assessed the degree to which dyslipidemia is more detrimental for men than for women.
Dyslipidemia and male sex enhanced the effect of one another in relation to AMI risk. The proportion of AMI cases among men with dyslipidemia attributable to this synergism alone was 0.46 (95% confidence interval = 0.35 to 0.57) for high total serum cholesterol, 0.23 (0.05 to 0.41) for low high-density lipoprotein (HDL) cholesterol, and 0.52 (0.42 to 0.62) for high non-HDL cholesterol. In contrast, obesity and hypertension were equally detrimental for men and women in relation to AMI risk, with a corresponding attributable proportion of 0.02 (-0.21 to 0.25) and -0.01 (-0.27 to 0.24), respectively.
Current clinical guidelines of dyslipidemia management do not distinguish between men and women in relation to primary prevention of AMI. Our results suggest that in middle age, dyslipidemia is much more detrimental for men than for women, and that preventing dyslipidemia has a greater potential to reduce the occurrence of AMI among men.
[Show abstract][Hide abstract] ABSTRACT: Previous studies have reported strong associations between birth order, maternal age, and suicide, but these results might have been confounded by socioeconomic and other factors. To control for such factors, we compared suicide risk between siblings and studied how maternal age at child birth and birth order influenced risk in a cohort study of 1,690,306 Norwegians born in 1967-1996 who were followed up until 2008. Using stratified Cox regression, we compared suicide risk within families with 2 or more children in which one died from suicide. Altogether, 3,005 suicides occurred over a mean follow-up period of 15 years; 2,458 of these suicides occurred among 6,741 siblings within families of 2 or more siblings. Among siblings, a higher position in the birth order was positively associated with risk; each increase in birth order was associated with a 46% (adjusted hazard ratio = 1.46, 95% confidence interval: 1.29, 1.66) higher risk of suicide. For each 10-year increase in maternal age at child birth, the offspring's suicide risk was reduced by 57% (adjusted hazard ratio = 0.43, 95% confidence interval: 0.30, 0.62). Our study suggests that confounding due to familial factors is not likely to explain the associations of birth order and maternal age at child birth with suicide risk.
American journal of epidemiology 03/2013; · 5.59 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Aims Insomnia is highly prevalent among heart failure patients, but only a few small studies have investigated insomnia symptoms and risk of heart failure. We aimed to assess the prospective association between self-reported insomnia symptoms and the risk of incident heart failure in a large Norwegian cohort.
Methods and results Baseline data on insomnia symptoms, including difficulty initiating sleep, difficulty maintaining sleep and having non-restorative sleep, socio-demographic variables, and health status, including established cardiovascular risk factors, were collected from 54 279 men and women 20–89 years of age who participated in the Nord-Trøndelag Health study (HUNT) between 1995 and 1997 and were free from known heart failure at baseline. The cohort was followed for incident heart failure from baseline through 2008. We used Cox proportional hazard models to assess the association of baseline insomnia symptoms with the risk of heart failure. A total of 1412 cases of heart failure occurred during a mean follow-up of 11.3 years (SD = 2.9 years), either identified at hospitals or by the National Cause of Death Registry. There was a dose-dependent association between the number of insomnia symptoms and risk of heart failure. The multi-adjusted hazard ratios were 0.96 (0.57–1.61), 1.35 (0.72–2.50), and 4.53 (1.99–10.31) for people with one, two, and three insomnia symptoms, compared with people with none of the symptoms (P for trend 0.021).
Conclusions Insomnia is associated with an increased risk of incident heart failure. If our results are confirmed by others and causation is proved, evaluation of insomnia symptoms might have consequences for cardiovascular prevention.
European Heart Journal 03/2013; · 14.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Previous studies have found an inverse association between insomnia and self-reported physical activity, but it is not clear whether insomnia is associated with cardiorespiratory fitness. Our aim was to investigate different insomnia symptoms in relation to the gold standard measure of cardiorespiratory fitness, i.e., peak oxygen uptake (VO(2peak)).
Cross-sectional population study.
Nord-Trøndelag County, Norway.
The group comprised 3,489 men and women who were free from cardiovascular or pulmonary diseases, cancer, and sarcoidosis and who did not use antihypertensive medication. They were included in the fully adjusted model when assessing all insomnia symptoms simultaneously.
For insomnia, the participants reported how often they had experienced sleep problems during the past 3 months, including difficulties falling asleep at night, repeated awakenings during the night, early awakenings without being able to go back to sleep, and daytime sleepiness. Response options were "never/almost never," "sometimes" or "several times a wk." To measure cardiorespiratory fitness, the participants were asked to walk or run on a treadmill with increasing speed and/or incline until exhaustion, and VO(2peak) was recorded. We found a modest inverse and graded association of the insomnia symptoms with VO(2peak). The association was independent of self-reported physical activity and was apparent for all insomnia symptoms except for early awakenings. We found a dose-response relation for a cumulative combination of insomnia symptoms and VO(2peak) for experiencing zero, one to two, or three to four symptoms (P for trend < 0.001).
We found a modest inverse association of insomnia with VO(2peak) independent of the conventional cardiovascular risk factors and self-reported physical activity. CITATION: Strand LB; Laugsand LE; Wisløff U; Nes BM; Vatten L; Janszky I. Insomnia symptoms and cardiorespiratory fitness in healthy individuals: the Nord-Trøndelag Health Study (HUNT). SLEEP 2013;36(1):99-108.
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: The prognostic role of job insecurity in coronary heart disease is unknown. We aimed to analyze whether job insecurity predicts mortality and recurrent events after a first acute myocardial infarction (AMI). METHODS: We studied non-fatal AMI cases involved in the Stockholm Heart Epidemiology Program who were in paid employment and younger than 65years (n=676). Shortly after their AMI, patients completed a questionnaire about job insecurity, demographic, work-related, clinical and lifestyle factors and participated in a clinical examination three months after discharge from the hospital. They were followed for 8.5years for mortality and cardiovascular events. RESULTS: After adjusting for previous morbidity, demographic and work-related factors, job insecurity was associated with an increased risk of the combined endpoint of cardiac death and non-fatal AMI, of total mortality and of heart failure; the hazard ratios (HR) and the 95% confidence intervals (CI) were 1.50 (1.02-2.22), 1.69 (1.04-2.75) and 1.62 (1.07-2.44), respectively. Similar associations, but with less statistical power were observed between job insecurity and cardiac death (HR (95% CI): 1.57 (0.80-3.09)) and stroke (HR (95% CI): 1.46 (0.71-3.02)), respectively. Adjustment for potential mediators, i.e. sleep problems, health behaviour, hypertension, blood lipids, glucose, inflammatory and coagulation factors did not alter considerably the relationship between job insecurity and the combination of cardiac mortality and non-fatal AMI. CONCLUSIONS: Our results suggest that job insecurity is an adverse prognostic factor in patients with a first AMI. Future studies are needed to confirm this finding and to determine the mechanisms underlying the observed relationship.
International journal of cardiology 08/2012; · 6.18 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To synthesise the association of shift work with major vascular events as reported in the literature.
Systematic searches of major bibliographic databases, contact with experts in the field, and review of reference lists of primary articles, review papers, and guidelines.
Observational studies that reported risk ratios for vascular morbidity, vascular mortality, or all cause mortality in relation to shift work were included; control groups could be non-shift ("day") workers or the general population.
Study quality was assessed with the Downs and Black scale for observational studies. The three primary outcomes were myocardial infarction, ischaemic stroke, and any coronary event. Heterogeneity was measured with the I(2) statistic and computed random effects models.
34 studies in 2,011,935 people were identified. Shift work was associated with myocardial infarction (risk ratio 1.23, 95% confidence interval 1.15 to 1.31; I(2)=0) and ischaemic stroke (1.05, 1.01 to 1.09; I(2)=0). Coronary events were also increased (risk ratio 1.24, 1.10 to 1.39), albeit with significant heterogeneity across studies (I(2)=85%). Pooled risk ratios were significant for both unadjusted analyses and analyses adjusted for risk factors. All shift work schedules with the exception of evening shifts were associated with a statistically higher risk of coronary events. Shift work was not associated with increased rates of mortality (whether vascular cause specific or overall). Presence or absence of adjustment for smoking and socioeconomic status was not a source of heterogeneity in the primary studies. 6598 myocardial infarctions, 17,359 coronary events, and 1854 ischaemic strokes occurred. On the basis of the Canadian prevalence of shift work of 32.8%, the population attributable risks related to shift work were 7.0% for myocardial infarction, 7.3% for all coronary events, and 1.6% for ischaemic stroke.
Shift work is associated with vascular events, which may have implications for public policy and occupational medicine.
[Show abstract][Hide abstract] ABSTRACT: To explore the hypothesis that insomnia may increase the risk of coronary heart disease through inflammatory mechanisms.
The association of high-sensitivity C-reactive protein (hsCRP) with self-reported symptoms of insomnia was examined. Participants were 8547 men and nonpregnant women who answered one or more insomnia-related questions and who had available hsCRP measurements in the Nord-Trøndelag Health Study. In multivariable linear regression analyses of the logarithm of hsCRP, we adjusted for established cardiovascular risk factors, psychosocial distress, chronic pain, and chronic somatic disorders.
Among men, difficulties initiating sleep and nonrestorative sleep were associated with increasing hsCRP levels after adjusting for age (B = 0.07, 95% confidence interval [CI] = 0.01-0.14, p for trend = .02 and B = 0.09, 95% CI = 0.02-0.15, p for trend = .006), but after multivariable adjustment, the associations were attenuated (B = 0.03, 95% CI = -0.03 to 0.09, p for trend = .30 and B = 0.06, 95% CI = -0.00 to 0.12, p for trend = .05). HsCRP was not associated with other insomnia-related symptoms. In women, there was no evidence for any association of symptoms of insomnia with hsCRP levels. Results indicated sex differences in the association between sleep characteristics and CRP (difficulties maintaining sleep, p interaction = .018; cumulative number of symptoms of insomnia, p interaction = .014; and symptoms of insomnia influencing work performance, p interaction = .039).
There were no consistent associations between symptoms of insomnia and hsCRP levels. Our results do not support the hypothesis that inflammation, as reflected by elevated levels of hsCRP, is an important factor linking insomnia to coronary heart disease.
Psychosomatic Medicine 06/2012; 74(5):543-53. · 4.08 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: PURPOSE: The objective of this study is to examine how different approaches of the current exercise recommendations for adults associate with V˙O2peak in a large healthy population. We further examined how a lower duration than recommended, if performed at very vigorous intensity, was related to V˙O2peak. METHODS: A total of 4631 healthy adults age 19-89 yr (2263 men and 2368 women) were tested for V˙O2peak (mean = 44.3 and 35.9 mL·kg·min for men and women, respectively). Information on exercise habits was collected through a questionnaire, including questions on frequency, duration, and relative intensity (Borg scale 6-20). A general linear model was applied to assess the associations between physical activity and V˙O2peak. RESULTS: V˙O2peak did not differ considerably between people who reported to exercise ≥150 min·wk (average = 216 min·wk, V˙O2peak = 45.2 and 36.5 mL·kg·min for men and women, respectively) with moderate intensity and people who reported 75-149 min·wk (average = 112.5 min·wk, V˙O2peak = 47.5 and 37.3 mL·kg·min for men and women) with vigorous intensity, but it was higher than that in people who reported inactivity (V˙O2peak = 40.1 and 32.3 mL·kg·min for men and women) or low-intensity exercise (V˙O2peak = 41.2 and 40.1 mL·kg·min for men and women). Reporting exercise at very vigorous intensity but with a duration of less than 75 min·wk (average = 49 min·wk) was associated with a V˙O2peak that was similarly high (47.6 and 36.7 mL·kg·min for men and women). CONCLUSION: Our findings support current recommendations by showing that exercise of both "moderate intensity-long duration" and "vigorous intensity-short duration" was associated with similarly high V˙O2peak. Our results also suggest that exercising at very vigorous intensity may be beneficial for V˙O2peak even with considerably lower total exercise time than expressed in today's recommendations.
Medicine and science in sports and exercise 04/2012; 44(10):1881-1889. · 4.48 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Daylight saving time shifts can be looked upon as large-scale natural experiments to study the effects of acute minor sleep deprivation and circadian rhythm disturbances. Limited evidence suggests that these shifts have a short-term influence on the risk of acute myocardial infarction (AMI), but confirmation of this finding and its variation in magnitude between individuals is not clear.
To identify AMI incidence on specific dates, we used the Register of Information and Knowledge about Swedish Heart Intensive Care Admission, a national register of coronary care unit admissions in Sweden. We compared AMI incidence on the first seven days after the transition with mean incidence during control periods. To assess effect modification, we calculated the incidence ratios in strata defined by patient characteristics.
Overall, we found an elevated incidence ratio of 1.039 (95% confidence interval, 1.003-1.075) for the first week after the spring clock shift forward. The higher risk tended to be more pronounced among individuals taking cardiac medications and having low cholesterol and triglycerides. There was no statistically significant change in AMI incidence following the autumn shift. Patients with hyperlipidemia and those taking statins and calcium-channel blockers tended to have a lower incidence than expected. Smokers did not ever have a higher incidence.
Our data suggest that even modest sleep deprivation and disturbances in the sleep-wake cycle might increase the risk of AMI across the population. Confirmation of subgroups at higher risk may suggest preventative strategies to mitigate this risk.
Sleep Medicine 03/2012; 13(3):237-42. · 3.49 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Maximal heart rate (HR(max) ) declines substantially with age, but the magnitude and possible modifying effect of gender, body composition, and physical activity are not fully established. The present study examined the relationship between HR(max) and age in 3320 healthy men and women within a wide age range using data from the HUNT Fitness Study (2007-2008). Subjects were included if a maximal effort could be verified during a maximal exercise test. General linear modeling was used to determine the effect of age on HR(max) . Subsequently, the effects of gender, body mass index (BMI), physical activity status, and maximal oxygen uptake were examined. Mean predicted HR(max) by three former prediction formulas were compared with measured HR(max) within 10-year age groups. HR(max) was univariately explained by the formula 211 - 0.64·age (SEE, 10.8), and we found no evidence of interaction with gender, physical activity, VO(2max) level, or BMI groups. There were only minor age-adjusted differences in HR(max) between these groups. Previously suggested prediction equations underestimated measured HR(max) in subjects older than 30 years. HR(max) predicted by age alone may be practically convenient for various groups, although a standard error of 10.8 beats/min must be taken into account. HR(max) in healthy, older subjects and women were higher than previously reported.
Scandinavian Journal of Medicine and Science in Sports 02/2012; · 3.21 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Insomnia is associated with increased risk of coronary heart disease (CHD), but the underlying mechanisms are not understood. To our knowledge, no previous studies have examined insomnia in relation to endothelial function, an indicator of preclinical atherosclerosis. Our aim was to assess the association of insomnia with endothelial function in a large population based study of healthy individuals.
A total of 4 739 participants free from known cardiovascular or pulmonary diseases, cancer, and sarcoidosis, and who were not using antihypertensive medication were included in the study. They reported how often they had experienced difficulties falling asleep at night, repeated awakenings during the night, early awakenings without being able to go back to sleep, and daytime sleepiness. Endothelial function was measured by flow mediated dilation (FMD) derived from the brachial artery.
We found no consistent association between the insomnia symptoms and endothelial function in multiadjusted models, but individual insomnia symptoms may be related to endothelial function. Among women who reported early awakenings, endothelial function may be lower than in women without this symptom (p = 0.03).
This study provided no evidence that endothelial function, an early indicator of atherosclerosis, is an important linking factor between insomnia and CHD. Further studies are needed to explore the complex interrelation between sleep and cardiovascular pathology.
PLoS ONE 01/2012; 7(12):e50933. · 3.53 Impact Factor