Sarcopenia and mild cognitive impairment in older adults from six low- and middle-income countries

Background:Little is known about the relationship between sarcopenia and mild cognitive impairment (MCI) in low- and middle-income countries (LMICs). Objective:This study aimed to investigate this association among community-dwelling adults aged≥65 years from six LMICs. Methods:Cross-sectional, nationally representative data from the Study on Global Ageing and Adult Health (SAGE) were analyzed. These data were obtained in China, Ghana, India, Mexico, Russia, and South Africa in 2007–2010. Participants were considered to have sarcopenia if they had low skeletal muscle mass (i.e., lower skeletal mass index) and a weak handgrip strength. MCI was defined using the National Institute on Aging-Alzheimer’s Association criteria. Multivariable logistic regression analysis was conducted to assess associations. Results:The final analytical sample consisted of 12,912 individuals aged≥65 years with preservation in functional abilities without stroke (mean [standard deviation] age 72.2 [10.8] years; 45.2% males). The overall prevalence of sarcopenia and MCI were 11.3% and 18.1%, respectively. After adjusting for potential confounders, there was a positive association between sarcopenia and MCI in all countries (i.e., odds ratio [OR] >  1) with the exception of South Africa, and the overall estimate was OR = 1.60 (95% confidence interval [CI] = 1.32–1.93) with a low level of between-country heterogeneity (I2 = 0.0%). Conclusion:There was a positive association between sarcopenia and MCI in this sample of older adults living in LMICs. Causality should be assessed in future longitudinal research, while the utility of sarcopenia as a marker of MCI should also be investigated.