Health and social correlates of dementia in oldest-old Mexican-origin populations

Introduction: Substantial gaps in research remain across oldest-old ethnic populations while the burden of dementia increases exponentially with age among Mexican and Mexican American older adults. Methods: Prevalence and correlates of dementia among individuals ≥82 years of age were examined using two population-based cohort studies: The Mexican Health and Aging Study (MHAS, n = 1078, 2012) and the Hispanic Established Populations for the Epidemiologic Study of the Elderly (HEPESE, n = 735, 2012–2013). The analytic MHAS and HEPESE samples had an average age of 86.4 and 88.0 years, 1.2 and 1.8 women to men, and 2.7 and 5.1 average years of education, respectively. Results: We identified 316 (29.2%) and 267 (36.3%) cases of likely dementia in the MHAS and HEPESE cohorts, respectively. For Mexicans but not Mexican Americans, age-adjusted prevalence rates of likely dementia were higher in women than men. For both populations prevalence rates increased with age and decreased with education for Mexican Americans but not for Mexicans. In both populations, odds of likely dementia increased with age. Health insurance for the low-income was significantly associated with higher odds of likely dementia for Mexican American men and women and Mexican women but not men. Living in extended households increased the odds of likely dementia in women, but not in men for both studies. Multiple cardiovascular conditions increased the odds of likely dementia for Mexicans but not for Mexican Americans. Discussion: Our study provides evidence of the high burden of dementia among oldest-old Mexicans and Mexican Americans and its association with health and social vulnerabilities.