Sex-specific All-cause Mortality is Associated with Adiposity in the Malaysian Elders Longitudinal Research (MELoR)...

While adiposity has been found to be protective against adverse outcomes in older adults, the role of muscle in this association remains underexplored. This study sought to evaluate sex-specific mortality associated with available adiposity indices in older adults and the potential role of muscle strength in this relationship.

Individuals aged ≥55 years were recruited from 2013 to 2015. Adiposity indices obtained were body mass index (BMI), percentage body fat (%BF), waist-to-hip ratio (WHR), and waist circumference (WC). Vital status up to June 2022 was determined through the National Registry Department.

Of the 1,347 included participants, mean age of 68.45±7.21 years, 57.1% female, and 11.2% deaths were recorded. Male who were underweight had increased mortality compared to male with normal BMI (hazard ratio [HR]=3.17, 95% confidence interval [CI] 1.35-7.47). Mortality was greater in male with %BF within the highest quartile (Q4) compared to the lowest quartile (Q1) (HR=4.72, 95% CI 2.07-10.78). Increased mortality in both male and female in Q4 for WHR compared to Q1 was influenced by age, as was increased mortality in female in Q4 for %BF. WC did not predict mortality in male or female. Increased mortality risk was present in male with normal muscle strength and increased %BF, and reduced muscle strength in male with low BMI.

Adiposity measured with BMI, WHR and WC had limited value in determining mortality risk at 9-year follow-up among individuals aged ≥55 years. Increased mortality was, however, observed in male with higher %BF but this could not be attributed to muscle strength.