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

Abstract

Background: 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.

Methods: 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.

Results: 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.

Conclusions: 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.