Elevated serum γ-glutamyl transferase is associated with low muscle function in adults independent of muscle mass

Abstract

Objective Elevated serum γ-glutamyl transferase (GGT), a hepatic cholestasis or liver damage marker, has been associated with low lean mass and adiposity. However, whether serum GGT can predict muscle function in adults remains unclear. The aim of this study was to determine whether an elevated serum GGT is associated with low peak weight-corrected jump power (JP) and low handgrip strength (HGS).

Methods This study included 662 individuals aged ≥50 y in the final cohort (women, 86%; mean age, 64.8 y). The primary outcome was low peak weight-corrected JP defined as <23.8 W/kg and <19W/kg in men and women, respectively, and the secondary outcome was low HGS (<28 kg in men; <18 kg in women).

Results Participants with low JP had a higher GGT level, older age, lower HGS, and higher body fat than those without low JP. Serum GGT showed a negative association with JP (adjusted β = –1.16, P = 0.005) and HGS (adjusted β = –0.92, P = 0.018). One log-unit increment in GGT was associated with elevated odds of low JP (adjusted odds ratio [aOR] 2.13, P = 0.002) after adjustment for age, sex, lean mass, and body fat percentage, particularly in individuals without hepatic steatosis (aOR, 2.30) versus those with hepatic steatosis (aOR, 0.80; Pinteraction = 0.020).

Conclusion Elevated serum GGT was associated with low muscle function in adults independent of age, muscle mass, and adiposity, indicating that serum GGT may play a role as an independent marker of muscle function.