Serum Albumin in Relation to Change in Muscle Mass, Muscle Strength, and Muscle Power in Older Men

Objectives To investigate the relationship between serum albumin and change in muscle mass, grip strength, and leg power. Design Prospective cohort. Setting Six U.S. academic medical centers. Participants Community-dwelling men aged 65 and older participating in the Osteoporotic Fractures in Men (MrOS) Study. Measurements Serum albumin was measured at baseline in 5,534 participants. Baseline serum albumin was examined in relation to change in appendicular skeletal muscle (ASM) mass, grip strength, and leg power after 2 and 4.6 years. Two-year change in serum albumin was examined with respect to simultaneous change in these outcomes in 1,267 participants. Results Baseline serum albumin <40 g/L was not associated with 2- or 4.6-year change in ASM mass, grip strength, or leg power before or after adjustment for confounders. There was no association between serum albumin change and change in grip strength. A statistically significant trend was observed between serum albumin change and change in ASM mass, but there was substantial overlap across confidence intervals (CIs). Participants with a marked decrease (>3 g/L) and mild decrease (12 g/L) in serum albumin over 2 years exhibited a modest change of -8.9 W (95% CI = -25.6 to -7.8 W) and -6.3 W (95% CI = -21.2 to -8.5 W) of leg power, respectively (P for trend = .02), compared with those with no decrease in albumin concentration. Conclusion Serum albumin demonstrated modest and inconsistent trends with loss of muscle mass and function. Low serum albumin within the normal range is not a risk factor for this process in elderly men.