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

Background: Age-related sarcopenia describes loss of muscle strength and often accompanies an increase in adiposity in elderly participants. Objectives: We examined the association of sarcopenic obesity, and changes in muscle strength and weight with risk of mortality. Design: Participants were 6,864 community dwelling men and women (mean±SD age 66.2 ± 6 9.5 years, 45.6% men) from the English Longitudinal Study of Ageing. Handgrip strength and body mass index were measured at baseline and at four years follow-up. Individual participant data were linked with death records from National Health Service registries. Sarcopenic obesity was defined as obese individuals (body mass index [BMI] ≥ 30 kg/m2) in the lowest tertile of sex specific grip strength (<35.3 kg men; < 19.6kg women). Results: Over an average follow up of 8 years there were 906 deaths. Compared with the reference group (normal BMI and highest hand grip tertile), the risk of all-cause mortality increased with reducing grip strength within each BMI category. For participants in the lowest hand grip tertile there was little difference in risk between normal BMI (Hazard ratio=3.25; 95% CI, 1.86, 5.65), overweight (2.50;1.44, 4.35), and obese (2.66; 1.86, 3.80), after adjustment for covariates. Compared to participants with stable weight and grip strength, risk of all-cause mortality was significantly greater in those experiencing weight loss over 4 years (2.21;1.32, 3.71) and reduced hand grip strength (1.53;1.07, 2.17), with the highest risk in those with weight loss and reduced strength (3.77; 2.54, 5.60). Conclusion: Sarcopenic obesity did not confer any greater risk than sarcopenia alone. Weight loss in combination with sarcopenia presented the greatest risk of mortality.