Emiliano Albanese

The global prevalence of dementia: A systematic review and metaanalysis

The evidence base on the prevalence of dementia is expanding rapidly, particularly in countries with low and middle incomes. A reappraisal of global prevalence and numbers is due, given the significant implications for social and public policy and planning.

Prevalence, Distribution, and Impact of Mild Cognitive Impairment in Latin America, China, and India: A 10/66 Population-Based Study

A set of cross-sectional surveys carried out in Cuba, Dominican Republic, Peru, Mexico, Venezuela, Puerto Rico, China, and India reveal the prevalence and between-country variation in mild cognitive impairment at a population level.

Dietary fish and meat intake and dementia in Latin America, China, and India: a 10/66 Dementia Research Group population-based study

Background: Evidence of an association between fish and meat consumption and risk of dementia is inconsistent and nonexistent in populations in developing countries. Objective: The objective was to investigate associations between fish and meat consumption with dementia in low- and middle-income countries. Design: One-phase cross-sectional surveys were conducted in all residents aged ≥65 y in 11 catchment areas in China, India, Cuba, the Dominican Republic, Venezuela, Mexico, and Peru. A total of 14,960 residents were assessed by using the 10/66 standardized protocol, which includes face-to-face interviews for dietary habits and a cross-culturally validated dementia diagnosis. Results: Dietary intakes and the prevalence of dementia varied between sites. We combined site-specific Poisson regression prevalence ratios (PRs) for the association between fish and meat consumption and dementia in 2 fixed-effect model meta-analyses adjusted for sociodemographic and health characteristics and fish and meat consumption as appropriate. We found a dose-dependent inverse association between fish consumption and dementia (PR: 0.81; 95% CI: 0.72, 0.91) that was consistent across all sites except India and a less-consistent, dose-dependent, direct association between meat consumption and prevalence of dementia (PR: 1.19; 95% CI: 1.07, 1.31). Conclusions: Our results extend findings on the associations of fish and meat consumption with dementia risk to populations in low- and middle-income countries and are consistent with mechanistic data on the neuroprotective actions of omega-3 (n–3) long-chain polyunsaturated fatty acids commonly found in fish. The inverse association between fish and prevalent dementia is unlikely to result from poorer dietary habits among demented individuals (reverse causality) because meat consumption was higher in those with a diagnosis of dementia.

Dementia severity and weight loss: a comparison across eight cohorts. The 10/66 study.

We aimed to investigate the association between dementia severity and weight loss in countries with low and middle incomes, where most prevalent cases reside.

Overweight and Obesity in Midlife and Brain Structure and Dementia 26 Years Later The AGES-Reykjavik Study

High adiposity in midlife might increase risk for late-life brain pathology, including dementia. Using data from the prospective Age, Gene/Environment Susceptibility-Reykjavik Study of men and women (born 1907-1935), we studied the associations of overweight and obesity at midlife (mean age, 50 (standard deviation, 4.7) years) with 1.5-T brain magnetic resonance imaging measures of infarct-like brain lesions, cerebral microbleeds, total brain volume, and white matter lesions volume, as well as dementia, in late life (mean age, 76 (standard deviation, 5.2) years). We used linear and Poisson models to estimate associations in 3,864 persons after adjustment for sociodemographic, health, and lifestyle characteristics. In midlife, the prevalence of overweight was 39% and that of obesity was 8%. After a mean follow-up of 26.2 (standard deviation, 4.9) years, midlife overweight and obesity were not associated with infarct-like brain lesions (relative risk (RR) = 0.82, 95% confidence interval (CI): 0.61, 1.10), cerebral microbleeds (RR = 0.69, 95% CI: 0.37, 1.32), total brain volume (β = 0.05, 95% CI: -0.34, 0.45), white matter lesions volume (β = -0.10, 95% CI: -0.20, 0.01), or dementia (RR = 0.91, 95% CI: 0.49, 1.72) compared with normal weight. These findings do not support the hypothesis that high body mass index in midlife modulates the risk for dementia.

The Association of Dementia With Upper Arm and Waist Circumference in Seven Low- and Middle-Income Countries: The 10/66 Cross-Sectional Surveys

BACKGROUNDnWeight loss in dementia contributes to morbidity and mortality but the distribution of anthropometric change and its consistency between populations are less clear. Our aim was to investigate and compare the associations of dementia with waist and upper arm circumference in elders from seven low- and middle-income nations.nnnMETHODSnCross-sectional surveys were conducted of 15,022 residents aged 65 years and older in Cuba, Mexico, Venezuela, Peru, Dominican Republic, China, and India. Dementia was assessed using a cross-culturally validated algorithm, and anthropometric measurements were taken. Associations with dementia and dementia severity (clinical dementia rating scale) were investigated in linear regression models, with fixed-effects meta-analyses used to investigate between-country heterogeneity.nnnRESULTSnDementia and increased dementia severity were both associated with smaller arm and waist circumferences with little evidence of confounding by sociodemographic and health status. Associations between dementia/clinical dementia rating and arm circumference were homogeneous between countries (Higgins I(2) 0% and 7%, respectively), whereas those with waist circumference were more heterogeneous (Higgins I(2) 67% and 62%, respectively).nnnCONCLUSIONSnAlthough cross-sectional, our findings are consistent with prospective observations of weight loss in dementia and suggest loss of both muscle and fat-the former being consistent across different settings and the latter being more context dependent.

No association between gain in body mass index across the life course and midlife cognitive function and cognitive reserve—The 1946 British birth cohort study

The association between lifelong body mass index (BMI) and cognitive function has not been comprehensively studied.

Weight loss and premature death: the 1946 British birth cohort study.

Objective The relationship between weight loss and mortality has important clinical and public health significance but has proved to be complex. Evidence is mixed and particularly limited on the association between weight loss in mid-life and premature death (i.e. before 65 years of age), a small albeit important segment of total mortality. We aimed to study the association between midlife weight change and mortality accounting for health and lifestyle characteristics, and also considering potential bias due to preexisting chronic diseases and smoking status. Design Longitudinal, population-based, ‘the 1946 British’ birth cohort study. Subjects and Measures In 2750 men and women, mortality from age 53 through 65 years was analyzed according to categories of measured 10 year weight change between 43 and 53 years. Coxs hazard ratios (HR) were progressively adjusted for socio-demographic, lifestyle and health characteristics. Results Nearly 20% of participants lost weight and over 50% gained 5 kg or more in midlife. There were 164 deaths. Compared to those who gained between 2 and 5 kg, those who lost 5 kg or more had an increased risk of premature death independently of midlife physical activity, socio-economic circumstances and educational attainment. This association was unaltered when highest weight loss (lost more than 15 Kg) (pu200a=u200a0.04) and early deaths were excluded (p<0.001), but was no longer significant after adjustment for cardiovascular risk factors and health status (HRu200a=u200a1.8; 95% CI: 0.9 to 3.5). Conclusion The inverse association between weight loss in midlife and higher risk of premature death may be explained by vascular risk factors and ill health. In consideration of the burden of premature death, closer monitoring of weight loss in mid-life is warranted.

Predicting risk of 2-year incident dementia using the CAMCOG total and subscale scores

BACKGROUNDnbeing able to identify individuals at high risk of dementia is important for diagnostics and intervention. Currently, there is no standard approach to assessing cognitive function in older aged individuals to best predict incident dementia.nnnOBJECTIVEnto identify cognitive changes associated with an increased risk of 2-year incident dementia using the Cambridge Cognitive Examination (CAMCOG).nnnDESIGNnlongitudinal population representative sample aged 65+ years.nnnMETHODSnindividuals were from the Medical Research Council Cognitive Function and Ageing Study. Classification and Regression Tree analysis was used to detect the optimal cut-off value for the CAMCOG total, subscales and composite memory and non-memory scores, for predicting dementia. Sensitivity and specificity of each cut-off score were assessed.nnnRESULTSnfrom the 2,053 individuals without dementia at the first assessment, 137 developed dementia at the 2-year follow-up. The results indicate similar discriminative accuracy for incident dementia based on the CAMCOG total, memory subscale and composite scores. However, sensitivity and specificity of cut-off values were generally moderate. Scores on the non-memory subscales generally had high sensitivity but low specificity. Compared with the CAMCOG total score they had significantly lower discriminative accuracy.nnnCONCLUSIONnin a population setting, cut-off scores from the CAMCOG memory subscales predicted dementia with reasonable accuracy. Scores on the non-memory scales have lower accuracy and are not recommend for predicting high-risk cases unless all non-memory subdomain scores are combined. The added value of cognition when assessed using the CAMCOG to other risk factors (e.g. health and genetics) should be tested within a risk prediction framework.

Hostile attitudes and effortful coping in young adulthood predict cognition 25 years later

Objective: We studied the relation of early-life (mean age 25 years) and mid-life (mean age 50 years) cognitive function to early measures of hostile attitudes and effortful coping. Methods: In 3,126 black and white men and women (born in 1955–1968) from the Coronary Artery Risk Development in Young Adults Study (CARDIA), we used linear regression to examine the association of hostile attitudes (Cook-Medley questionnaire) and effortful coping assessed at baseline (1985–1986) to cognitive ability measured in 1987 and to a composite cognitive Z score of tests of verbal memory, psychomotor speed, and executive function ascertained in midlife (2010–2011). Results: Baseline hostility and effortful coping were prospectively associated with lower cognitive function 25 years later, controlling for age, sex, race, education, long-term exposure to depression, discrimination, negative life events, and baseline cognitive ability. Compared to the lowest quartile, those in the highest quartile of hostility performed 0.21 SD units lower (95% confidence interval [CI] −0.39, −0.02). Those in the highest quartile of effortful coping performed 0.30 SD units lower (95% CI −0.48, −0.12) compared to those in the lowest quartile. Further adjustment for cumulative exposure to cardiovascular risk factors attenuated the association with the cognitive composite Z score for hostility. Conclusions: Worse cognition in midlife was independently associated with 2 psychological characteristics measured in young adulthood. This suggests that interventions that promote positive social interactions may have a role in reducing risk of late-age cognitive impairment.