Monocyte chemoattractant protein-1: a proinflammatory cytokine elevated in sarcopenic obesity

Jun Pei Lim,1,2 Bernard P Leung,3 Yew Yoong Ding,1,2 Laura Tay,1,2 Noor Hafizah Ismail,2,4 Audrey Yeo,2 Suzanne Yew,2 Mei Sian Chong1,2 1Department of Geriatric Medicine, 2Institute of Geriatrics and Active Ageing, 3Department of Rheumatology, Allergy and Immunology, 4Department of Community and Continuing Care, Tan Tock Seng Hospital, Singapore Objective: Sarcopenic obesity (SO) is associated with poorer physical outcomes and functional status in the older adult. A proinflammatory milieu associated with central obesity is postulated to enhance muscle catabolism. We set out to examine associations of the chemokine monocyte chemoattractant protein-1 (MCP-1) in groups of older adults, with sarcopenia, obesity, and the SO phenotypes.Methods: A total of 143 community dwelling, well, older adults were recruited. Cross-sectional clinical data, physical performance, and muscle mass measurements were collected. Obesity and sarcopenia were defined using revised National Cholesterol Education Program (NCEP) obesity guidelines and those of the Asian Working Group for Sarcopenia. Serum levels of MCP-1 were measured by enzyme-linked immunosorbent assay (ELISA).Results: In all, 25.2% of subjects were normal, 15.4% sarcopenic, 48.3% obese, and 11.2% were SO. The SO groups had the lowest appendicular lean mass, highest percentage body fat, and lowest performance scores on the Short Physical Performance Battery and grip strength. The MCP-1 levels were significantly different, with the highest levels found in SO participants (P<0.05).Conclusion: Significantly raised MCP-1 levels in obese and SO subjects support the theory of chronic inflammation due to excess adiposity. Longitudinal studies will reveal whether SO represents a continuum of obesity causing accelerated sarcopenia and cardiovascular events, or the coexistence of two separate conditions with synergistic effects affecting functional performance. Keywords: chemokine C-C motif ligand 2 (CCL-2), elderly, sarcopeni