Perceived Stress and Mild Cognitive Impairment among 32,715 Community-Dwelling Older Adults across Six Low- and Middle-Income Countries

Background: Perceived stress may be a modifiable risk factor for mild cognitive impairment (MCI) and ultimately dementia, but studies on this topic from low-and middle-income countries (LMICs) are lacking. Objective: We assessed the association between perceived stress and MCI in six LMICs (China, Ghana, India, Mexico, Russia, and South Africa) using nationally representative data. Methods: Cross-sectional, community-based data on individuals aged >= 50 years from the World Health Organization's Study on Global Ageing and Adult Health were analyzed. The definition of MCI was based on the National Institute on Ageing-Alzheimer's Association criteria. A perceived stress score (range 0 [lowest stress] to 10 [highest stress]) was computed based on two questions from the Perceived Stress Scale. Multivariable logistic regression analysis was conducted to assess the association between perceived stress and MCI. Results: The mean (SD) age of the 32,715 participants was 62.1 (15.6) years and 51.7% were females. After adjustment for potential confounders including depression, in the overall sample, a one-unit increase in the perceived stress score was associated with a 1.14 (95% CI = 1.11-1.18) times higher odds for MCI. The association was similar among those aged 50-64 and >= 65 years. Countrywise analysis showed that there was a moderate level of between-country heterogeneity in this association (I-2 = 59.4%), with the strongest association observed in Russia (OR = 1.33, 95% CI = 1.15-1.55). Conclusion: If our study results are confirmed in prospective studies, addressing perceived stress may have an impact in reducing the risk for MCI and subsequent dementia in LMICs. (C) 2018 S. Karger AG, Basel