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

Abstract

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

Methods: Cross-sectional catchment area surveys were performed in Cuba, Mexico, Venezuela, Peru, Dominican Republic, Puerto Rico, China, and India. In 16,538 older adults (≥65 years of age), significant weight loss was self-reported and confirmed by an informant. We conducted neuropsychological testing and clinical and neurological assessments. Dementia severity was determined by applying a validated algorithm and was quantified by the Clinical Dementia Rating Scale.

Results: The characteristics of those who reported weight loss varied across countries. In Poisson models, after controlling for relevant covariates and for waist and arm circumferences, dementia severity was associated with reported weight loss (pooled prevalence ratios [95% confidence intervals {CI}] 2.19 [1.98, 2.41]; 3.81 [3.35, 4.33]; and 5.18 [4.41, 6.10] for CDR 0.5, 1, and 2/3, respectively, compared with CDR 0). The association increased linearly through stages of dementia severity in all countries (P for trend < .001), and between-country heterogeneity was minimal.

Conclusions: We found a strong gradient effect in the direct association between dementia severity and reported weight loss, homogeneous across sites from eight countries, consistent with mechanistic data on the role of neurodegenerative processes on energy balance and with dietary changes due to disease severity. Considering the well-recognized effect of weight loss on morbidity and mortality and the large number affected by dementia in less resourced countries, amelioration of weight loss in dementia patients should be considered with priority in these settings.

Keywords: Aging; Cross-cohort; Dementia; Dementia severity; Developing countries; Epidemiology; Meta-analysis; Observational study; Older adults; Population-based sample; Weight loss.

Fig. 1

Increase in weight loss risk by dementia severity. Pooled estimates are from country-specific, fully adjusted Poisson models using fixed-effects method meta-analysis as for model 3 in Table 3 (i.e., adjusted for gender; age; education; number of assets; food insecurity [week frequency of hunger through shortage of food]; living circumstances [live alone or with spouse only vs larger families arrangements]; physical activity level [inactive, mild, moderate, high level]; smoking status [never, ex-, current smoker]; week meat and fish [none, some, or most days]; week portions of fruits and vegetables; number of physical impairments [≥3]; and reported clinical diagnosis of stroke, diabetes, and gastrointestinal and heart disease.