Olivia I. Okereke

Depression and Risk of Stroke Morbidity and Mortality: A Meta-analysis and Systematic Review

CONTEXT Several studies have suggested that depression is associated with an increased risk of stroke; however, the results are inconsistent. OBJECTIVE To conduct a systematic review and meta-analysis of prospective studies assessing the association between depression and risk of developing stroke in adults. DATA SOURCES A search of MEDLINE, EMBASE, and PsycINFO databases (to May 2011) was supplemented by manual searches of bibliographies of key retrieved articles and relevant reviews. STUDY SELECTION We included prospective cohort studies that reported risk estimates of stroke morbidity or mortality by baseline or updated depression status assessed by self-reported scales or clinician diagnosis. DATA EXTRACTION Two independent reviewers extracted data on depression status at baseline, risk estimates of stroke, study quality, and methods used to assess depression and stroke. Hazard ratios (HRs) were pooled using fixed-effect or random-effects models when appropriate. Associations were tested in subgroups representing different participant and study characteristics. Publication bias was evaluated with funnel plots and Begg test. RESULTS The search yielded 28 prospective cohort studies (comprising 317,540 participants) that reported 8478 stroke cases (morbidity and mortality) during a follow-up period ranging from 2 to 29 years. The pooled adjusted HRs were 1.45 (95% CI, 1.29-1.63; P for heterogeneity <.001; random-effects model) for total stroke, 1.55 (95% CI, 1.25-1.93; P for heterogeneity = .31; fixed-effects model) for fatal stroke (8 studies), and 1.25 (95% CI, 1.11-1.40; P for heterogeneity = .34; fixed-effects model) for ischemic stroke (6 studies). The estimated absolute risk differences associated with depression were 106 cases for total stroke, 53 cases for ischemic stroke, and 22 cases for fatal stroke per 100,000 individuals per year. The increased risk of total stroke associated with depression was consistent across most subgroups. CONCLUSION Depression is associated with a significantly increased risk of stroke morbidity and mortality.

Bidirectional Association Between Depression and Metabolic Syndrome: A systematic review and meta-analysis of epidemiological studies

OBJECTIVE Epidemiological studies have repeatedly investigated the association between depression and metabolic syndrome (MetS). However, the results have been inconsistent. This meta-analysis aimed to summarize the current evidence from cross-sectional and prospective cohort studies that evaluated this association. RESEARCH DESIGN AND METHODS MEDLINE, EMBASE, and PsycINFO databases were searched for articles published up to January 2012. Cross-sectional and cohort studies that reported an association between the two conditions in adults were included. Data on prevalence, incidence, unadjusted or adjusted odds ratio (OR), and 95% CI were extracted or provided by the authors. The pooled OR was calculated separately for cross-sectional and cohort studies using random-effects models. The I2 statistic was used to assess heterogeneity. RESULTS The search yielded 29 cross-sectional studies (n = 155,333): 27 studies reported unadjusted OR with a pooled estimate of 1.42 (95% CI 1.28–1.57; I2 = 55.1%); 11 studies reported adjusted OR with depression as the outcome (1.27 [1.07–1.57]; I2 = 60.9%), and 12 studies reported adjusted OR with MetS as the outcome (1.34 [1.18–1.51]; I2 = 0%). Eleven cohort studies were found (2 studies reported both directions): 9 studies (n = 26,936 with 2,316 new-onset depression case subjects) reported adjusted OR with depression as the outcome (1.49 [1.19–1.87]; I2 = 56.8%), 4 studies (n = 3,834 with 350 MetS case subjects) reported adjusted OR with MetS as the outcome (1.52 [1.20–1.91]; I2 = 0%). CONCLUSIONS Our results indicate a bidirectional association between depression and MetS. These results support early detection and management of depression among patients with MetS and vice versa.

Coffee, Caffeine, and Risk of Depression Among Women

BACKGROUND Caffeine is the worlds most widely used central nervous system stimulant, with approximately 80% consumed in the form of coffee. However, studies that analyze prospectively the relationship between coffee or caffeine consumption and depression risk are scarce. METHODS A total of 50,739 US women (mean age, 63 years) free of depressive symptoms at baseline (in 1996) were prospectively followed up through June 1, 2006. Consumption of caffeine was measured from validated questionnaires completed from May 1, 1980, through April 1, 2004, and computed as cumulative mean consumption with a 2-year latency period applied. Clinical depression was defined as self-reported physician-diagnosed depression and antidepressant use. Relative risks of clinical depression were estimated using Cox proportional hazards regression models. RESULTS During 10 years of follow-up (1996-2006), 2607 incident cases of depression were identified. Compared with women consuming 1 or less cup of caffeinated coffee per week, the multivariate relative risk of depression was 0.85 (95% confidence interval, 0.75-0.95) for those consuming 2 to 3 cups per day and 0.80 (0.64-0.99; P for trend<.001) for those consuming 4 cups per day or more. Multivariate relative risk of depression was 0.80 (95% confidence interval, 0.68-0.95; P for trend=.02) for women in the highest (≥550 mg/d) vs lowest (<100 mg/d) of the 5 caffeine consumption categories. Decaffeinated coffee was not associated with depression risk. CONCLUSIONS In this large longitudinal study, we found that depression risk decreases with increasing caffeinated coffee consumption. Further investigations are needed to confirm this finding and to determine whether usual caffeinated coffee consumption can contribute to depression prevention.

Bidirectional association between depression and obesity in middle-aged and older women

Objective:Although it has been hypothesized that the depression–obesity relation is bidirectional, few studies have addressed this hypothesis in a prospective setting. We aimed to examine the bidirectional relationship in middle-aged and elderly women.Subjects:A total of 65 955 women aged 54–79 years in the Nurses’ Health Study were prospectively followed from 1996 to 2006 with updated information on body weight, depression status and various covariates every 2 years. Depression was defined as self-report of physician-diagnosed depression and/or antidepressant use. Obesity was defined as a BMI ⩾30.0 kg m−2. The first three waves (1996–2000) were used as the baseline period and the last three waves (2002–2006) were used as the follow-up period.Results:After adjusting for baseline age, physical activity, comorbidities, BMI and other covariates, depression at the baseline period was associated with an increased risk of obesity at the follow-up period in all women (multivariate-adjusted odds ratio (OR), 1.38; 95% confidence interval (95% CI), 1.24–1.53) and baseline non-obese women (OR, 1.51; 95% CI, 1.36–1.67). In the opposite direction, after adjusting for baseline age, physical activity, comorbidities, depression status and other covariates, obese women at baseline had a moderately increased risk of depression at the follow-up period compared with normal-weight women (OR, 1.11; 95% CI, 1.03–1.18), and this association was similar for new onset of depression (OR for obese versus normal weight women, 1.10; 95% CI, 1.02–1.20).Conclusions:Our results suggest a bidirectional association between depression and obesity in middle-aged and elderly women. Future studies are needed to confirm our findings in different populations, and investigate the potential mechanisms underlying this association. Our results underscore the importance of early detection and proper behavioral modifications to lower the burden of both conditions.

Type 2 Diabetes Mellitus and Cognitive Decline in Two Large Cohorts of Community-Dwelling Older Adults

OBJECTIVES: To relate diabetes mellitus (DM) status and duration to late‐life cognitive impairment and decline in men and women.

Adiposity and weight change in mid-life in relation to healthy survival after age 70 in women: prospective cohort study

Objective To examine the hypothesis that mid-life adiposity is associated with a reduced probability of maintaining an optimal health status among those who survive to older ages. Design Prospective cohort study. Setting The Nurses’ Health Study, United States. Participants 17 065 women who survived until at least the age of 70, provided information on occurrence of chronic disease, cognitive function, physical function, and mental health at older ages, and were free from major chronic diseases at mid-life (mean age was 50 at baseline in 1976). Main outcome measures Healthy survival to age 70 and over was defined as having no history of 11 major chronic diseases and having no substantial cognitive, physical, or mental limitations. Results Of the women who survived until at least age 70, 1686 (9.9%) met our criteria for healthy survival. Increased body mass index (BMI) at baseline was significantly associated with linearly reduced odds of healthy survival compared with usual survival, after adjustment for various lifestyle and dietary variables (P<0.001 for trend). Compared with lean women (BMI 18.5-22.9), obese women (BMI ≥30) had 79% lower odds of healthy survival (odds ratio 0.21, 95% confidence interval 0.15 to 0.29). In addition, the more weight gained from age 18 until mid-life, the less likely was healthy survival after the age of 70. The lowest odds of healthy survival were among women who were overweight (BMI ≥25) at age 18 and gained ≥10 kg weight (0.18, 0.09 to 0.36), relative to women who were lean (BMI 18.5-22.9) and maintained a stable weight. Conclusions These data provide evidence that adiposity in mid-life is strongly related to a reduced probability of healthy survival among women who live to older ages, and emphasise the importance of maintaining a healthy weight from early adulthood.

Mediterranean diet and cognitive function in older age.

Background: Adherence to a Mediterranean diet may help prevent cognitive decline in older age, but studies are limited. We examined the association of adherence to the Mediterranean diet with cognitive function and decline. Methods: We included 6174 participants, aged 65+ years, from the cognitive substudy of the Women’s Health Study. Women provided dietary information in 1998 and completed a cognitive battery 5 years later, followed by two assessments at 2-year intervals. The primary outcomes were composite scores of global cognition and verbal memory. The alternate Mediterranean diet adherence nine-point score was constructed based on intakes of vegetables, fruits, legumes, whole grains, nuts, fish, red and processed meats, moderate alcohol, and the ratio of monounsaturated-to-saturated fats. Results: After multivariable adjustment, the alternate Mediterranean diet score was not associated with trajectories of repeated cognitive scores (P for score quintiles medians-x-time interaction = 0.26 for global cognition and 0.40 for verbal memory), nor with overall global cognition and verbal memory at older ages, assessed by averaging the three cognitive measures (P trend = 0.63 and 0.44, respectively). Among alternate Mediterranean diet components, a higher monounsaturated-to-saturated fats ratio was associated with more favorable cognitive trajectories (P for ratio quintiles medians-x-time = 0.03 for global cognition and 0.05 for verbal memory). Greater whole grain intake was not associated with cognitive trajectories but was related to better averaged global cognition (P trend = 0.02). Conclusions: In this large study of older women, we observed no association of the Mediterranean diet with cognitive decline. Relations between individual Mediterranean diet components, particularly whole grains, and cognitive function merit further study.

Dietary fat types and 4‐year cognitive change in community‐dwelling older women

A study was undertaken to relate dietary fat types to cognitive change in healthy community‐based elders.

Early Intervention to Reduce the Global Health and Economic Burden of Major Depression in Older Adults

Randomized trials for selective and indicated prevention of depression in both mixed-aged and older adult samples, conducted in high-income countries (HICs), show that rates of incident depression can be reduced by 20-25% over 1-2 years through the use of psychoeducational and psychological interventions designed to increase protective factors. Recurrence of major depression can also be substantially reduced through both psychological and psychopharmacological strategies. Additional research is needed, however, to address the specific issues of depression prevention in older adults in low- and middle-income countries (LMICs). The growing number of older adults globally, as well as workforce issues and the expense of interventions, makes it important to develop rational, targeted, and cost-effective risk-reduction strategies. In our opinion, one strategy to address these issues entails the use of lay health counselors (LHCs), a form of task shifting already shown to be effective in the treatment of common mental disorders in LMICs. We suggest in this review that the time is right for research into the translation of depression-prevention strategies for use in LMICs.

The relation between past exposure to fine particulate air pollution and prevalent anxiety: observational cohort study

Objective To determine whether higher past exposure to particulate air pollution is associated with prevalent high symptoms of anxiety. Design Observational cohort study. Setting Nurses’ Health Study. Participants 71 271 women enrolled in the Nurses’ Health Study residing throughout the contiguous United States who had valid estimates on exposure to particulate matter for at least one exposure period of interest and data on anxiety symptoms. Main outcome measures Meaningfully high symptoms of anxiety, defined as a score of 6 points or greater on the phobic anxiety subscale of the Crown-Crisp index, administered in 2004. Results The 71 271 eligible women were aged between 57 and 85 years (mean 70 years) at the time of assessment of anxiety symptoms, with a prevalence of high anxiety symptoms of 15%. Exposure to particulate matter was characterized using estimated average exposure to particulate matter <2.5 μm in diameter (PM2.5) and 2.5 to 10 μm in diameter (PM2.5-10) in the one month, three months, six months, one year, and 15 years prior to assessment of anxiety symptoms, and residential distance to the nearest major road two years prior to assessment. Significantly increased odds of high anxiety symptoms were observed with higher exposure to PM2.5 for multiple averaging periods (for example, odds ratio per 10 µg/m3 increase in prior one month average PM2.5: 1.12, 95% confidence interval 1.06 to 1.19; in prior 12 month average PM2.5: 1.15, 1.06 to 1.26). Models including multiple exposure windows suggested short term averaging periods were more relevant than long term averaging periods. There was no association between anxiety and exposure to PM2.5-10. Residential proximity to major roads was not related to anxiety symptoms in a dose dependent manner. Conclusions Exposure to fine particulate matter (PM2.5) was associated with high symptoms of anxiety, with more recent exposures potentially more relevant than more distant exposures. Research evaluating whether reductions in exposure to ambient PM2.5 would reduce the population level burden of clinically relevant symptoms of anxiety is warranted.