Mathew Niti

National University of Singapore, Singapore, Singapore

Are you Mathew Niti?

Claim your profile

Publications (24)89.11 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: A limited but growing body of evidence supports a significant role of antioxidant and anti-inflammatory micronutrients in pulmonary health. We investigated the associations of dietary and supplemental intakes of vitamins A, C, E and D, Se and n-3 PUFA with pulmonary function in a population-based study. Population-based, cross-sectional study and data analysis of fruits and vegetables, dairy products and fish, vitamins A, C, E and D, Se and n-3 PUFA supplemental intakes, pulmonary risk factors and spirometry. Chinese older adults (n 2478) aged 55 years and above in the Singapore Longitudinal Ageing Studies. In multiple regression models that controlled simultaneously for gender, age, height, smoking, occupational exposure and history of asthma/chronic obstructive pulmonary disease, BMI, physical activity, and in the presence of other nutrient variables, daily supplementary vitamins A/C/E (b = 0·044, se = 0·022, P = 0·04), dietary fish intake at least thrice weekly (b = 0·058, se = 0·016, P < 0·0001) and daily supplementary n-3 PUFA (b = 0·068, se = 0·032, P = 0·034) were individually associated with forced expiratory volume in the first second. Supplemental n-3 PUFA was also positively associated with forced vital capacity (b = 0·091, se = 0·045, P = 0·045). No significant association with daily dairy product intake, vitamin D or Se supplements was observed. The findings support the roles of antioxidant vitamins and n-3 PUFA in the pulmonary health of older persons.
    Public Health Nutrition 09/2013; · 2.25 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Research on long-term exposure to electromagnetic fields on cognition is lacking. We investigated the associations between frequent digital mobile phone use and global and domain-specific cognitive changes in older persons, a vulnerable group experiencing age-associated cognitive decline. We assessed 871 non-demented Chinese participants in the Singapore Longitudinal Ageing Studies cohort on the frequency of digital mobile phone use, neurocognitive performance and confounding variables at baseline, and neurocognitive performance at the 4-year follow-up. Findings showed that digital mobile phone users were typically self-selected to possess characteristics favoring better cognitive functioning and concomitantly demonstrate better performance on cognitive tasks. There was evidently no significant deleterious effect of digital mobile phone use on cognitive functioning in older people. Findings suggest, however, that digital mobile phone use may have an independent facilitating effect on global and executive functioning. Bioelectromagnetics 33:176–185, 2012. © 2011 Wiley Periodicals, Inc.
    Bioelectromagnetics 02/2012; 33(2). · 2.02 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Research on the effects of dietary nutrients on respiratory health in human populations have not investigated curcumin, a potent anti-oxidant and anti-inflammatory compound present principally in turmeric used in large amounts in Asian curry meals. To examine the association of curry intake with pulmonary function among smokers and non-smokers. The frequency of curry intake, respiratory risk factors and spirometry were measured in a population-based study of 2,478 Chinese older adults aged 55 and above in the Singapore Longitudinal Ageing Studies. Curry intake (at least once monthly) was significantly associated with better FEV(1) (b = 0.045±0.018, p = 0.011) and FEV(1)/FVC (b = 1.14±0.52, p = 0.029) in multivariate analyses that controlled simultaneously for gender, age, height, height-squared, smoking, occupational exposure and asthma/COPD history and other dietary or supplementary intakes. Increasing levels of curry intake ('never or rarely', 'occasional', 'often', 'very often') were associated with higher mean adjusted FEV(1) (p for linear trend = 0.001) and FEV(1)/FVC% (p for linear trend = 0.048). Significant effect modifications were observed for FEV(1) (curry* smoking interaction, p = 0.028) and FEV(1)/FVC% (curry*smoking interaction, p = 0.05). There were significantly larger differences in FEV(1) and FEV(1)/FVC% between curry intake and non-curry intake especially among current and past smokers. The mean adjusted FEV(1) associated with curry intake was 9.2% higher among current smokers, 10.3% higher among past smokers, and 1.5% higher among non-smokers. The possible role of curcumins in protecting the pulmonary function of smokers should be investigated in further clinical studies.
    PLoS ONE 01/2012; 7(12):e51753. · 3.53 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The relationships between blood pressure and depression are unclear. There are inconsistent reports of an association between low blood pressure and depressive symptoms. In a population-based sample of 2611 Chinese older adults aged 55 years and above, including participants with treated (n=1088), untreated (n=545), or no hypertension (n=978), depressive symptoms were determined by the 15-item Geriatric Depression Scale (> or =5), and current systolic blood pressure and diastolic blood pressure measurements were used to classify participants into high, normal, and low blood pressure groups. Estimates of association were adjusted for confounding by use of antihypertensive and depressogenic drugs and other covariables in hierarchical regression analyses. Systolic blood pressure and diastolic blood pressure were negatively associated with Geriatric Depression Scale scores, independent of other variables. Low systolic blood pressure (odds ratio [OR] 1.54; 95% confidence interval [CI], 1.07-2.22), low diastolic blood pressure (OR 1.67; 95% CI, 0.98-2.85), and low systolic blood pressure or diastolic blood pressure (or both) (OR 1.55; 95% CI, 1.10-2.19) were independently associated with depressive symptoms. The associations with depressive symptoms were particularly observed for low systolic blood pressure (OR 2.13; 95% CI, 1.13-4.03) among treated hypertensive participants, and low diastolic blood pressure (OR 2.42; 95% CI, 1.26-4.68) among untreated or nonhypertensive participants. Low blood pressure was independently associated with depressive symptoms in both older subjects who were treated for hypertension and those who were not.
    The American journal of medicine 04/2010; 123(4):342-9. · 5.30 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To investigate whether the effect of depressive symptoms on the risk of cognitive decline and incident cognitive impairment (CI) in cognitively well-functioning older persons differed between men and women and whether sex differences in cerebrovascular factors might explain this. Prospective cohort study. General community. One thousand four hundred eighty-seven well-functioning Chinese older adults (Mini-Mental State Examination (MMSE) score > or =24) assessed at baseline for the presence of depressive symptoms (Geriatric Depression Scale score > or =5), and covariates (age, apolipoprotein E epsilon4, education, smoking, alcohol drinking, and vascular risk factors and diseases). Incident CI and change in MMSE were assessed at 2-year follow-up. In the whole sample, participants with depression showed significantly more incident CI than those without (5.7% vs 2.6%, P=.04; adjusted odds ratio (OR)=2.29, 95% confidence interval (CI)=1.05-5.00. Significantly higher OR was observed only in men (OR=4.75, 95% CI=1.22-18.5) and not for women (OR=1.29). There was a correspondingly greater rate of cognitive decline in participants with depressive symptoms that was observed to be marked only in men and not in women. The association was accentuated in subgroups with hypertension or vascular factors, but the sex differences in association were consistently observed. The association between depressive symptoms and risk of cognitive decline was observed only in men and was not explained by sex differences in vascular factors. The comorbid presence of underlying cerebral vascular pathology or multi-infarct disease was possibly not a mediating factor but might amplify the process of cognitive decline.
    Journal of the American Geriatrics Society 06/2009; 57(6):1058-63. · 4.22 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: to examine the effect of late life engagement in continued work involvement or volunteer activities during retirement on mental well-being. two waves of data from the Singapore Longitudinal Ageing Studies were analyzed for 2,716 Singaporeans aged 55 or above at baseline and 1,754 at 2-year follow-up. Trained research nurses interviewed participants (non-volunteering retiree, volunteering retiree, and working seniors) on mental health status (geriatric depression scale, Mini Mental State Examination, positive mental wellbeing and life satisfaction). about 88% of seniors were retired (78% non-volunteering, 10% volunteering) and 12% were still working in paid employment or business. At baseline and 2 year follow up, and regardless of physical health status, volunteering retirees and working seniors gave significantly better MMSE cognitive performance scores, fewer depressive symptoms, and better mental well-being and life satisfaction than non-volunteering retirees. the results of this study suggest that continued work involvement or volunteerism provides opportunities for social interaction and engagement and may be associated with enhanced mental well-being. Future research should clarify which specific aspects of volunteerism are related to long-term mental well-being.
    Age and Ageing 06/2009; 38(5):531-7. · 3.82 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: To investigate the independent associations between folate, B12, and homocysteine levels and depressive symptoms in older adults. Cross-sectional study. Resident population in southeast Singapore. Six hundred sixty-nine community-living noninstitutionalized Chinese adults aged 55 and older. Laboratory values of folate, vitamin B12, and homocysteine were examined for their independent relationships with depressive symptoms (Geriatric Depression Scale (GDS) score > or =5). Respondents with depression (n=178) had lower mean serum folate concentrations (21.5 nmol/L) than those without (n=491, 24.0 nmol/L, P=.04). There was a linear relationship between descending quartiles of folate concentrations and increasing odds of association with depressive symptoms, independent of other risk factors (demographic, psychosocial, alcohol and smoking, chronic morbidity, functional status, nutritional risk, albumin, anemia, depression-inducing medications, use of antidepressants and vitamin supplements), including B12 and homocysteine (P for trend=.02). The odds ratio (OR) of association between low folate (lowest quartile: <14.6 nmol/L) and depressive symptoms independent of other risk factors, including homocysteine and B12, was 1.72 (95% confidence interval (CI)=1.11-2.66). Vitamin B12 across a range of values did not show a linear association, but B12 deficiency (<180 pmol/L) appeared to be significantly associated with depressive symptoms (OR=2.68, 95% CI=1.20-6.00), independent of folate and homocysteine. Decreasing and low levels of serum folate and deficient levels of B12 were associated with greater risk of depressive symptoms in older Chinese adults.
    Journal of the American Geriatrics Society 05/2009; 57(5):871-6. · 4.22 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Few studies have evaluated the validation of 15-item Geriatric Depression Scale (GDS-15) in a heterogeneous population with different age, ethnicity and comorbidities of elderly users of social services in the community. To assess the criterion validity and reliability of the GDS-15 and its equivalence across different gender, age groups, ethnicity and different comorbidities in community living elderly and nursing homes residents. A validation sample of non-demented 4253 elderly (age > or = 60 years), who regularly use community based care corner, senior activity center, day care center, sheltered homes and nursing homes were interviewed using the GDS-15. Structured clinical interview (SCID) was used to make DSM-IV diagnosis of major depressive disorder (MDD). The overall sensitivity and specificity were 0.97 and 0.95, respectively (area under curve, AUC was 0.98). The overall Cronbach's alpha was 0.80, and intraclass coefficient of test--retest reliability over 2 weeks was 0.83 and inter-rater reliability was 0.94 (intra-class) and 0.99 (Cohen's kappa). Although some items in the GDS-15 appeared to be biased by gender, age and ethnicity, there were no clinically significant differences in test performance among different age, gender, ethnicity and comorbidities at cutoff of 4/5. The GDS-15 was a reliable and valid screening for MDD across different age, gender, ethnicity and chronic illness status in the community and social service setting.
    Aging and Mental Health 05/2009; 13(3):376-82. · 1.68 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Depression occurs commonly among patients with COPD, but the independent association of depression and COPD and the effect of depression on COPD outcomes are not well established. A population sample of 2402 Chinese aged >or=55 with and without COPD (characteristic symptoms of chronic cough, sputum or breathlessness and airflow obstruction and FEV(1)/FVC<0.70) was assessed on Geriatric Depression Scale (score>or=5), dependence on basic activities of daily living (ADL), SF-12 health status, smoking and medication behaviour. The 189 respondents with COPD showed higher depressive symptoms prevalence (22.8%) than 2213 respondents without COPD (12.4%); multivariate odd ratio (OR) was 1.86; 95% CI, 1.25-2.75 after controlling for confounding risk factors. In multivariate analyses of respondents with COPD, those who were depressed (N=43), compared to those who were not (N=146), were more likely to report ADL disability (OR=2.89, p=0.049) poor or fair self-reported health (OR=3.35, p=0.004), poor SF-12 PCS scores (OR=2.35, p=0.041) and SF-12 MCS scores (OR=4.17, p<0.001). Depressive symptoms were associated with COPD independent of known risk factors. In COPD participants, depressive symptoms were associated with worse health and functional status and self-management.
    Respiratory medicine 02/2009; 103(6):895-901. · 2.33 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The precise relationship between depression and cognitive decline in older adults is unclear. We investigated the influence of apolipoprotein E (APOE)-epsilon4 genotype in modulating the effect of depressive symptoms on cognitive decline. Prospective cohort study of 1,487 cognitively high-functioning Chinese older adults. Depressive symptoms (Geriatric Depression Scale score >/=5) and Mini-Mental State Examination (MMSE) were assessed at baseline, and cognitive decline (at least 1-point drop in MMSE) at 1-2 years after baseline. There was no significant difference in cognitive decline between depressed (32.9%) and nondepressed (31.5%) participants in the whole sample or among non-APOE-epsilon4 carriers. Among APOE-epsilon4 carriers, depressed participants showed more cognitive decline (40.0%) than their nondepressed counterparts (28.6%), odds ratio = 2.89, 95% confidence interval: 1.03-8.12; p = .04, after controlling for age, gender, education, vascular risk factors/events, smoking, alcohol drinking, physical functioning, subjective memory complaint, length of follow-up, and baseline MMSE scores (p for interaction = .03). Our study suggests that the presence of the APOE-epsilon4 allele significantly enhanced the risk of cognitive decline associated with depressive symptoms. This finding should be independently replicated in future studies.
    The Journals of Gerontology Series A Biological Sciences and Medical Sciences 01/2009; 64(2):306-11. · 4.31 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: To examine the association between serum albumin and cognitive impairment and decline in community-living older adults. Population-based cohort study, followed up to 2 years; serum albumin, apolipoprotein E (APOE)-epsilon4, and cognitive impairment measured at baseline and cognitive decline (> or =2-point drop in Mini-Mental State Examination (MMSE) score). Odds ratios were controlled for age, sex, education, medical comorbidity, hypertension, diabetes mellitus, cardiac disease, stroke, smoking, alcohol drinking, depression, APOE-epsilon4, nutritional status, body mass index, anemia, glomerular filtration rate, and baseline MMSE. Local area whole population. One thousand six hundred sixty-four Chinese older adults aged 55 and older. The mean age of the cohort was 66.0+/-7.3, 65% were women, mean serum albumin was 42.3+/-3.1 g/L, and mean MMSE score was 27.2+/-3.2. Lower albumin tertile was associated with greater risk of cognitive impairment in cross-sectional analysis (low, odds ratio (OR)=2.30, 95% confidence interval (CI)=1.31-4.03); medium, OR=1.59, 95% CI=0.88-2.88) versus high (P for trend=.002); and with cognitive decline in longitudinal analyses: low, OR=1.73, 95% CI=1.18-2.55; medium, OR=1.32, 95% CI=0.89-1.95, vs high (P for trend=.004). In cognitively unimpaired respondents at baseline (MMSE> or =24), similar associations with cognitive decline were observed (P for trends <.002). APOE-epsilon4 appeared to modify the association, due mainly to low rates of cognitive decline in subjects with the APOE-epsilon4 allele and high albumin. Low albumin was an independent risk marker for cognitive decline in community-living older adults.
    Journal of the American Geriatrics Society 12/2008; 57(1):101-6. · 4.22 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Few studies have explored the relationship between orthostatic hypotension (OH) and cognition. The aim of this study was to examine the association of OH with cognitive impairment and decline in a cohort of Chinese elderly, and its effect modification by blood pressure (BP) status at baseline. Among 2,321 community-living older adults, free of cardiovascular disease and stroke, baseline BP measurements were used to determine the presence of OH and categorize participants as hypotensives, normotensives or hypertensives. The Mini-Mental State Examination (MMSE) was used to assess cognitive impairment (MMSE score <24). Cognitive decline (decrease in MMSE score by > or =1) was assessed from 1 to 2 years of follow-up for 1,347 participants without baseline cognitive impairment. Mean age of the subjects was 65.5 years and 381 (16.6%) showed OH. OH was not associated with cognitive impairment overall. However, among hypotensives, OH increased the odds of cognitive impairment (OR = 4.1, 95% CI = 1.11-15.1), while hypertensives with OH showed reduced odds of cognitive impairment (OR = 0.48, 95% CI = 0.26-0.90). Among cognitively intact participants, OH was not associated with cognitive decline overall or in BP subgroups. The increased risk of cognitive impairment in hypotensives with OH suggests that hypotension with OH may be an early comorbid marker of a primary incipient dementia.
    Dementia and Geriatric Cognitive Disorders 10/2008; 26(3):239-46. · 2.79 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: to examine the relationships between serum albumin, haemoglobin and body mass index (BMI) with cognitive performance among community-living older adults. design--population-based cross-sectional study; setting--local community in Southeast Region of Singapore; subjects--Chinese older adults aged 55 and above (N = 2, 550); measurements--serum albumin, haemoglobin, BMI and Mini-Mental State Examination (MMSE). in multivariable analyses controlling for gender, age, education and vascular risk factors, low albumin in the bottom quintile (OR 2.04; 95% CI 1.22-3.41) and low haemoglobin in the bottom quintile (OR 1.56; 95% CI 1.00-2.47) and low BMI with chronic comorbidity (OR 1.73; 95%CI 1.02-2.95) were independently associated with poor cognitive performance (MMSE < or = 23). Among cognitively intact respondents (MMSE > or = 24), albumin concentration showed a significant inverse linear relationship with MMSE scores (P for trend =0.002). low albumin, low haemoglobin and low BMI (in the presence of chronic comorbidity) are independently associated with poor cognitive performance in community-living older adults.
    Age and Ageing 07/2008; 37(4):423-9. · 3.82 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Laboratory research suggests that tea has potential neurocognitive protective effects, but this is not established in humans. We aimed to examine the relation between tea intake and cognitive impairment and decline. Among community-living Chinese adults aged > or = 55 y in the Singapore Longitudinal Ageing Studies cohort, we measured tea consumption at baseline and administered the Mini-Mental State Examination (MMSE) at baseline and 1-2 y later. Cognitive impairment was defined as an MMSE score < or = 23 and cognitive decline as a drop in MMSE score of > or = 1 point. We performed cross-sectional analysis of baseline data from 2501 participants and longitudinal analysis of data from 1438 cognitively intact participants. Odds ratios (ORs) of association were calculated in logistic regression models that adjusted for potential confounders. Total tea intake was significantly associated with a lower prevalence of cognitive impairment, independent of other risk factors. Compared with the ORs for rare or no tea intake, the ORs for low, medium, and high levels of tea intake were 0.56 (95% CI: 0.40, 0.78), 0.45 (95% CI: 0.27, 0.72), and 0.37 (95% CI: 0.14, 0.98), respectively (P for trend < 0.001). For cognitive decline, the corresponding ORs were 0.74 (95% CI: 0.54, 1.00), 0.78 (95% CI: 0.55, 1.11), and 0.57 (95% CI: 0.32, 1.03), respectively (P for trend = 0.042). These effects were most evident for black (fermented) and oolong (semi-fermented) teas, the predominant types consumed by this population. In contrast, no association between coffee intake and cognitive status was found. Regular tea consumption was associated with lower risks of cognitive impairment and decline.
    American Journal of Clinical Nutrition 07/2008; 88(1):224-31. · 6.50 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To determine the association of the metabolic syndrome (MS) with cognitive decline in a Chinese older population. In a prospective cohort study of 1,352 community-living Chinese older adults without cognitive impairment (Mini Mental State Examination, MMSE <24) and without cardiovascular disease and stroke, the authors assessed baseline MS (defined according to International Diabetic Federation Criteria). Cognitive decline was predefined as at least 2-point drop in MMSE score at follow-up 1-2 years after baseline assessment. MS was present in 26.3% of the participants at baseline and was significantly associated with the risk of cognitive decline (odds ratio, 1.42: confidence interval, 1.01-1.98), after controlling for potential confounding by age, gender, education, smoking, alcohol drinking, depressive symptoms, APOE-e4 status, level of leisure activities, baseline MMSE, and length of follow-up. The MS was associated with increased risk of cognitive decline in Chinese older adults.
    The American journal of geriatric psychiatry: official journal of the American Association for Geriatric Psychiatry 06/2008; 16(6):519-22. · 3.35 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Item response bias (also called differential item functioning, DIF) in Instrumental Activities of Daily Living (IADL) occurs when members of different groups possessing the same disability level do not have the same probability of responding positively for a given item(s). This study aimed to identify the extent of DIF by gender, age, ethnicity, and dementia groups in IADL estimates in Asian (Chinese, Malays, and Indian) elderly subjects. Data of 1,072 noninstitutionalized elderly subjects were analyzed using Multiple-Indicator Multiple-Cause (MIMIC) latent variable modeling. Given the same functional level, older elderly were less likely to report needing help with preparing meals; men were more likely to report needing help with preparing meals, doing laundry, and taking medication; Malays and demented elderly were more likely to report needing help with using the telephone. The impact of DIF on group differences in cognitive IADL was highest for ethnicity (58%), followed by gender (50%), and dementia (23%); whereas 92% and 5% of group differences in physical IADL were for gender and age, respectively. Item-response bias in IADL scale by gender, age, ethnicity, and dementia should be considered in direct comparisons of disability status among population groups.
    Journal of Clinical Epidemiology 05/2007; 60(4):366-74. · 5.48 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Depressive symptoms are common among patients with chronic obstructive pulmonary disease (COPD), but depression's impact on COPD outcomes has not been fully investigated. We evaluated the impact of comorbid depression on mortality, hospital readmission, smoking behavior, respiratory symptom burden, and physical and social functioning in patients with COPD. In this prospective cohort study, 376 consecutive patients with COPD hospitalized for acute exacerbation were followed up for 1 year. The independent associations of baseline comorbid depression (designated as a Hospital Anxiety and Depression Scale score of > or =8) with mortality, hospital readmission, length of stay, persistent smoking, and quality of life (determined by responses to the St George Respiratory Questionnaire) were evaluated after adjusting for potential confounders. The prevalence of depression at admission was 44.4%. The median follow-up duration was 369 days, during which 57 patients (15.2%) died, and 202 (53.7%) were readmitted at least once. Multivariate analyses showed that depression was significantly associated with mortality (hazard ratio, 1.93; 95% confidence interval, 1.04-3.58), longer index stay (mean, 1.1 more days; P = .02) and total stay (mean, 3.0 more days; P = .047), persistent smoking at 6 months (odds ratio, 2.30; 95% confidence interval, 1.17-4.52), and 12% to 37% worse symptoms, activities, and impact subscale scores and total score on the St George Respiratory Questionnaire at the index hospitalization and 1 year later, even after controlling for chronicity and severity of COPD, comorbidities, and behavioral, psychosocial, and socioeconomic variables. Comorbid depressive symptoms in patients with COPD are associated with poorer survival, longer hospitalization stay, persistent smoking, increased symptom burden, and poorer physical and social functioning. Interventions that reduce depressive symptoms may potentially affect COPD outcomes.
    Archives of Internal Medicine 02/2007; 167(1):60-7. · 11.46 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Clock Drawing Tests are commonly used for cognitive screening, but their clinical utility has not yet been studied in Chinese Singaporeans. We examined the usefulness of a Clock Drawing Test, CLOX, in detecting dementia in our population and explored its performance in the dementia subtypes, Alzheimer's disease (AD), and the vascular composite group (VCG) of AD with cerebrovascular disease and vascular dementia. CLOX was administered to 73 subjects (49.3%) with dementia and 75 healthy controls (50.7%). Receiver operating characteristic analysis determined the diagnostic accuracy and optimal cut-off scores, stratified by education. Analysis of Variance was used to compare CLOX scores between AD and VCG. The diagnostic accuracy (area under the curve) was 84 and 85% for CLOX1 and CLOX2, respectively. Cut-offs at 10 for CLOX1 and 12 for CLOX2 yielded sensitivities of 75.3 and 75%, and specificities of 76 and 80%, respectively. The mean CLOX1 but not CLOX2 scores for AD (8.1) and VCG (5.5) remained significantly different (p = 0.002) after adjustment for the covariates age, gender, education, MMSE and dementia stage. Our results support CLOX as a valid cognitive screen in Singaporean Chinese with adequate psychometric properties. In addition, CLOX may aid as an adjunct in differentiating AD from dementia with a vascular element, e.g. AD with cerebrovascular disease and vascular dementia.
    Dementia and Geriatric Cognitive Disorders 02/2007; 24(3):193-200. · 2.79 Impact Factor
  • Article: P-159
    Alzheimers & Dementia - ALZHEIMERS DEMENT. 01/2007; 3(3).
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The relations of elevated homocysteine, low folate, and vitamin B-12 with cognitive performance in nondemented elderly are not well established. Limited research data suggest differential effects of homocysteine and folate on specific cognitive domains. The aim was to examine the independent associations of homocysteine, folate, and vitamin B-12 with cognitive performance in high-functioning elderly Chinese. Homocysteine, folate, and vitamin B-12 concentrations were measured in fasting blood samples of 451 Chinese aged >or=55 y with Mini-Mental State Examination scores >or=24 and who were considered fully independent based on Activities of Daily Living score. Cognitive functions were assessed by a neuropsychological test battery. Independent associations (standardized beta) were determined in multiple linear regression models that simultaneously controlled for potential confounders. Log-transformed homocysteine was inversely associated with performance on Block Design (beta = -0.319, P = 0.006) and the written Symbol Digit Modality Test (beta = -0.129, P = 0.031). Log-transformed folate was significantly associated with Rey Auditory Verbal Learning Test delayed recall (beta = 0.139, P = 0.010), verbal learning (beta = 0.112, P = 0.038), percentage of forgetting (beta = -0.139, P = 0.013), and the Categorical Verbal Fluency test (beta = 0.104, P = 0.042). Vitamin B-12 was not significantly associated with any cognitive test score. In this high-functioning elderly Chinese population, elevated homocysteine is associated with deficits in constructional ability and processing speed and folate is associated with measures of episodic memory and language. Our results provide support for differential effects of homocysteine and folate on specific cognitive functions.
    American Journal of Clinical Nutrition 12/2006; 84(6):1506-12. · 6.50 Impact Factor