Sarcopenic obesity, weight loss, and mortality: The English Longitudinal Study of Ageing

Abstract

Background: Age-related sarcopenia describes the loss of muscle strength and often accompanies an increase in adiposity in the elderly. Objective: We examined the association of sarcopenic obesity and changes in muscle strength and weight with the risk of mortality. Design: Participants (n = 6864) were community-dwelling men and women (45.6% men; 54.4% women; mean ± SD age: 66.2 ± 9.5 y) from the English Longitudinal Study of Ageing. Handgrip strength and body mass index (BMI; in kg/m2) were measured at baseline and at a 4-y follow-up. Individual participant data were linked with death records from National Health Service registries. Sarcopenic obesity was defined as obese individuals (BMI ≥30) in the lowest tertile of sex-specific grip strength (<35.3 kg for men and <19.6 kg for women). Results: There were 906 deaths over a mean follow-up of 8 y. Compared with the reference group (normal BMI and highest handgrip tertile), the risk of all-cause mortality increased as grip strength reduced within each BMI category. For participants in the lowest handgrip tertile, there was little difference in the risk between normal BMI (HR: 3.25; 95% CI: 1.86, 5.65), overweight (HR: 2.50; 95% CI: 1.44, 4.35), and obesity (HR: 2.66; 95% CI: 1.86, 3.80) after adjusting for covariates. The risk of all-cause mortality was significantly greater in participants who experienced weight loss over 4 y (HR: 2.21; 95% CI: 1.32, 3.71) and/or reduced hand grip strength (HR: 1.53; 95% CI: 10.07, 2.17) than in those with stable weight and grip strength, with the highest risk in those with both weight loss and reduced strength (HR: 3.77; 95% CI: 2.54, 5.60). Conclusions: Sarcopenic obesity did not confer any greater risk than sarcopenia alone. Weight loss combined with sarcopenia presented the greatest risk of mortality.