Physical Activity With Alanine Aminotransferase and Gamma-Glutamyltransferase: Implications of Liver Pathology on the Relationship Between Physical Activity and Mortality

Objective: Examine the association between objectively-measured moderate-to-vigorous physical activity (MVPA) and engagement in self-reported muscle strengthening activities (MSA) with alanine aminotransferase (ALT) and gamma-glutamyltransferase (GGT), and in turn, how each of these parameters associate with of all-cause mortality.

Methods: Data from the 2003–2006 NHANES were employed, with follow-up through December 31, 2011 (N = 5030; 20+ yrs). Physical activity was assessed via accelerometry; MSA was assessed via survey; and ALT and GGT were assessed via a blood sample. Linear regression and Cox proportional hazard models were used.

Results: MVPA (βadjusted = 0.15; 95% CI: –0.45 to 0.76; P = .60) was not associated with ALT, but MSA was (β adjusted = –0.31; 95% CI: –0.56 to –0.05; P = .02). With regard to GGT, MSA was not significant (β adjusted = –0.12; 95% CI: –0.71 to 0.47; P = .67), nor was MVPA (β adjusted = –1.10; 95% CI: –2.20 to 0.06; P = .06). Higher ALT levels were associated with increased allcause mortality risk (HRadjusted = 1.05; 95% CI: 1.02 to 1.06; P < .001).

Conclusion: Physical activity is favorably associated with markers of hepatic inflammation, and higher levels of markers of hepatic inflammation are associated with increased mortality risk. These findings suggest that physical activity may help protect against premature mortality through its influence on liver pathology.