Physical Activity is Associated With Fewer Subjective Cognitive Complaints in 47 Low- and Middle-Income Countries.

OBJECTIVES: To determine the association between physical activity (PA) and subjective cognitive complaints (SCCs), and the influential factors in this association. DESIGN: Cross-sectional study. SETTING AND PARTICIPANTS: Community-based data of the World Health Survey, which included 248,504 individuals from 47 low- and middle-income countries (LMICs), were analyzed [mean age = 38.6 (standard deviation 16.1) years; 50.7% female]. METHODS: PA was assessed with the International Physical Activity Questionnaire. Participants were grouped into those who meet (high PA) the 150 minutes of moderate-to-vigorous intensity PA per week recommendation, and those who do not (low PA). Two questions on subjective memory and learning complaints in the past 30 days were used (scales ranged from 1 to 5, with higher scores representing more severe SCC). Multivariable ordinal logistic regression and mediation analyses were performed. RESULTS: Overall, after adjusting for sociodemographic and a wide range of behavioral, psychological, and physical factors, low PA was associated with a higher risk for having more severe subjective memory complaints [odds ratio (OR) = 1.10, 95% confidence interval (CI) = 1.04-1.23] and learning complaints (OR = 1.18, 95% CI = 1.12-1.26). Significant associations were only observed among the middle-aged (45-64 years; learning complaints OR = 1.19, 95% CI = 1.06-1.33) and older populations (>/=65 years; memory complaints OR = 1.31, 95% CI = 1.15-1.49, and learning complaints OR = 1.41, 95% CI = 1.24-1.60). Chronic physical conditions, sleep problems, depression, and anxiety explained between 7.7% and 29.4% of the PA-SCC association among those aged >/=45 years. CONCLUSIONS AND IMPLICATIONS: Low PA was associated with increased odds for more severe SCCs in middle-aged and older adults in LMICs. Given the particularly rapid increase in dementia in LMICs, more longitudinal research is warranted from this setting to understand the utility of PA promotion in the prevention of cognitive impairment.