Functional Measures of Sarcopenia: Prevalence, and Associations with Functional Disability in 10,892 Adults Aged 65 Years and Over from Six Lower- and Middle-Income Countries.

Identification of sarcopenia in lower- and middle-income countries (LMICs) is limited by access to technologies that assess muscle mass. We investigated associations between two functional measures of sarcopenia, grip strength and gait speed (GS), with functional disability in adults from six LMICs. Data were extracted from the World Health Organization (WHO) Study on global AGEing and adult health Wave 1 (2007-2010) for adults (≥ 65 years) from China, Mexico, Ghana, India, Russia and South Africa (n = 10,892, 52.8% women). We calculated country-specific prevalence of low grip strength, slow GS (≤ 0.8 m/s), and both measures combined. Using multivariable negative binomial regression, we separately assessed associations between low grip strength, slow GS, and both measures combined, with the WHO Disability Assessment Schedule 2.0, accounting for selected socioeconomic factors. In women, low grip strength ranged from 7 in South Africa to 51% in India; in men, it ranged from 17 in Russia to 51% in Mexico. Country-specific proportions of slow GS ranged from 77 in Russia, to 33% in China. The concomitant presence of both was the lowest in South Africa and the highest in India (12.3% vs. 33%). Independent of age, those with both low grip strength and slow GS had between 1.2- and 1.5-fold worse functional disability scores, independent of comorbidities, low education, and low wealth (all country-dependent). Low grip strength, slow GS, and the combination of both, were all associated with higher levels of functional disability, thus indicating these objective measures offer a reasonably robust estimate for potential poor health outcomes.