Dementia prevalence in an indigenous population from Brazilian amazon

Abstract

Background: Few studies have investigated the relationship between self-rated health and dementia. We examined the relationship between self-rated health and incident dementia, and investigated the impact of cognitive complaints, depressive symptoms, and functional status on this relationship. Methods: Participants of the 3C study, a prospective French cohort study composed of 8,169 non-demented community-dwelling men and women aged 1⁄465 years, were asked to rate their health at the baseline examination in 1999-2001. They were followed over an 8 year period during which three extensive follow-up examinations were performed (at years 2, 4, and 8) and dementia was screened and diagnosed. Hazard ratios of dementia according to baseline self-rated health (good, fair, or poor) were estimated with a Cox model adjusted for demographic factors, vascular risk factors or diseases, and non-vascular chronic diseases. Stratified analyses according to the presence or absence of cognitive complaints, depressive symptoms, or functional disability were also realized. Results: During the 46,990 person-years of follow-up, 618 participants developed dementia. Risk of dementia was increased in participants with poor (adjusted hazard ratio: 1.70, 95% CI 1.22 to 2.37) or fair (adjusted hazard ratio: 1.34, 95% CI 1.13 to 1.59) self-rated health compared to those with good self-rated health. Poor self-rated health was associated with both Alzheimer’s disease (1.48, 1.00 to 2.24) and vascular dementia (3.38, 1.25 to 9.17). Self-rated health was a stronger predictor of dementia in participants without cognitive complaints [risk of dementia in those rating their health as poor but without cognitive complaints: 1.96 (1.24 to 3.09), P1⁄40.004] and in those without functional disability (1.76, 1.14 to 2.71). Moreover, the predictive value of self-rated health was independent of depressive symptoms. Conclusions: There are few recognized predictive factors for dementia that can be assessed easily. Our findings suggest that a simple self-rated health question could help raise awareness of medical doctors about patient’s risk of dementia, especially in those without conditions indicative of potential cognitive impairment, such as cognitive complaints or disabilities.