Supplemental use of antioxidant vitamins and subsequent risk of cognitive decline and dementia.

There are conflicting reports about the potential role of vitamin antioxidants in preventing and/or slowing the progression of various forms of cognitive impairment including Alzheimer's disease (AD). We examined longitudinal data from the Canadian Study of Health and Aging, a population-based, prospective 5-year investigation of the epidemiology of dementia among Canadians aged 65+ years. Our primary objective was to examine the association between supplemental use of antioxidant vitamins and subsequent risk of significant cognitive decline (decrease in 3MS score of 10 points or more) among subjects with no evidence of dementia at baseline (n=894). We also explored the relationship between vitamin supplement use and incident vascular cognitive impairment (VCI; including a diagnosis of vascular dementia, possible AD with vascular components and VCI but not dementia), dementia (all cases) and AD. After adjusting for potential confounding factors assessed at baseline, subjects reporting a combined use of vitamin E and C supplements and/or multivitamin consumption at baseline were significantly less likely (adjusted OR 0.51; 95% CI 0.29-0.90) to experience significant cognitive decline during a 5-year follow-up period. Subjects reporting any antioxidant vitamin use at baseline also showed a significantly lower risk for incident VCI (adjusted OR 0.34, 95% CI 0.13-0.89). A reduced risk for incident dementia or AD was not observed. Our findings suggest a possible protective effect for antioxidant vitamins in relation to cognitive decline but randomized controlled trials are required for confirmation.

Does self-rated health predict survival in older persons with cognitive impairment?

OBJECTIVES: To determine whether baseline self-rated health (SRH) independently predicted survival in an older Canadian population and to investigate the role of cognition on the SRH-mortality relationship. DESIGN: Population-based prospective cohort study. SETTING: Ten Canadian provinces, community-based. PARTICIPANTS: A total of 8,697 community-dwelling participants aged 65 and older. MEASUREMENTS: Self-reported measures of overall health, physical function, comorbidities, and demographic characteristics were obtained by interview. Cognitive ability was ascertained using the Modified Mini-Mental State Examination (3MS). Participants were followed for their survival status from the initial interview in 1991 until October 31, 1996. RESULTS: Subjects with reports of poor SRH were significantly more likely to die during follow-up than those reporting good SRH, after adjusting for relevant covariates (adjusted hazard ratio (AHR)=1.38, 95% confidence interval (CI)=1.24-1.53). SRH was also related to other measures of health status across levels of cognitive impairment. SRH remained a significant predictor of mortality in subjects with mild to moderate cognitive impairment (AHR=1.26, 95% CI=1.01-1.59) but not in those with severe cognitive impairment (AHR=1.00, 95% CI=0.76-1.31). CONCLUSION: This study supports the utility of SRH assessments in predicting survival of individuals with mild to moderate cognitive impairment. The findings highlight the potential role of complex cognitive processes underlying the SRH-mortality relationship.

Prevalence and potential consequences of benzodiazepine use in senior citizens: results from the Canadian Study of Health and Aging.

OBJECTIVES: The aim of this study was to evaluate changes in benzodiazepine use over time, and the association between benzodiazepine use and select outcomes. DESIGN: A five-year longitudinal cohort study in subjects 65 years of age and older. SETTING: Select urban communities and institutions across Canada with senior citizens. PARTICIPANTS: Subjects who were first seen in 1990 to 1991, recontacted in 1996, and agreed to undergo a second clinical examination. Mortality rates were based on the initial 2914 subjects enrolled. MEASUREMENTS: Number and type of medications used. Outcomes (mortality, incident institutionalization, change in cognition, depression, function, self-rated health) associated with benzodiazepine use. Logistic regression to predict outcomes and pattern of benzodiazepine use. RESULTS: Mean number of medications being taken by senior citizens increased to 5.8 from 3.9. The proportion of subjects using benzodiazepines at time 1 and time 2 was similar (26.4% versus 25.2%). Affect, self-rated health, cognition, function and incident institutionalization were significantly associated with benzodiazepine use. Subjects with a depressed mood were more likely to be prescribed a benzodiazepine (37%) than an antidepressant (26.9%). CONCLUSION: Benzodiazepines were associated with a number of adverse outcomes. The relative benefits and risks of benzodiazepine use in an older population should be re-examined.

Serum folate levels and subsequent adverse cerebrovascular outcomes in elderly persons.

Recent epidemiologic studies have shown an association between low serum folate levels and risk of vascular disease, including stroke and various types of vascular cognitive impairment. We examined data from the Canadian Study of Health and Aging (CSHA), a population-based, prospective 5-year investigation of the epidemiology of dementia among Canadians aged 65+ years. The risk of an adverse cerebrovascular event (including vascular dementia, vascular cognitive impairment, or fatal stroke) during follow-up, was assessed according to serum folate quartiles among subjects with no evidence of dementia at baseline (n = 369). After adjusting for certain covariates, including cardiovascular disease and nutritional indices, education, smoking and baseline cognitive status, the risk estimate for an adverse cerebrovascular event associated with the lowest folate quartile compared with the highest quartile was OR 2.42 (95% CI 1.04-5.61). Results from stratified analyses also showed that relatively low serum folate was associated with a significantly higher risk of an adverse cerebrovascular event among female (OR 4.02, 95% CI 1.37-11.81) but not male (OR 1.02, 95% CI 0.25-4.13) subjects. Among the total sample, there was a consistent trend toward poorer health and cognitive outcomes during follow-up (including mortality, cognitive decline and dementia) among those in the lowest folate quartile compared with the highest quartile. Low serum folate levels are independently associated with a significantly higher risk of an adverse cerebrovascular event, including vascular dementia and stroke death, among older, cognitively vulnerable persons.