Lower serum albumin concentration and change in muscle mass: The Health, Aging and Body Composition Study

Abstract

Background: Low albumin concentrations in older persons increase the risk of poor health outcomes, including functional decline. Objective: The aim of the study was to investigate the association between serum albumin concentration and skeletal muscle loss (sarcopenia) in old age. Design: Serum albumin concentration was measured in 1882 black and white men and women aged 70-79 y participating in the Health, Aging and Body Composition Study. Five-year changes in appendicular skeletal muscle mass (ASMM), total-body fat-free mass (FFM), and trunk lean mass (TLM) were measured by using dual-energy X-ray absorptiometry. Confounders included health and lifestyle factors, which are markers of inflammation and protein intake. Results: A low albumin concentration (<38 g/L) was observed in 21.2% of the study participants. After adjustment for confounders, the mean (±SE) change in ASMM was -82 ± 26 g per 3-g/L lower albumin concentration (P = 0.002). This association remained after persons with a low albumin concentration (<38 g/L) were excluded. The decline in ASMM in subjects with low albumin concentrations was almost 30% higher (-930 ± 56 g) than that in those with albumin concentrations ≥42 g/L (-718 ± 38 g; P < 0.01). The association between albumin and change in ASMM remained after additional adjustment for weight change. A weak association was observed for FFM, whereas no association was observed for TLM, which suggests a specific role of albumin in skeletal muscle change. Conclusions: Lower albumin concentrations, even above the clinical cutoff of 38 g/L, are associated with future loss of ASMM in older persons. Low albumin concentration may be a risk factor for sarcopenia. © 2005 American Society for Clinical Nutrition.