Combined associations of liver enzymes and obesity with diabetes mellitus prevalence: The Tohoku Medical Megabank Community-based Cohort Study.

BACKGROUND Alanine aminotransferase (ALT) and gamma-glutamyl transferase (GGT) are enzymes associated with diabetes mellitus (DM) prevalence. However, limited information is available regarding the association of liver enzymes and DM consistently present in obese and non-obese individuals. We examined whether the combination of ALT and GGT enzymes is associated with the prevalence of DM regardless of obesity in a general Japanese population. METHODS We conducted a cross-sectional study of 62,786 participants aged ≥20 years who lived in Miyagi and Iwate, Japan. We divided all the participants into eight groups according to the ALT level (low: <30 IU/L and high: ≥30 IU/L), GGT level (low: <50 IU/L and high: ≥50 IU/L), and the presence of obesity. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) using multivariable logistic regression analysis, adjusting for potential confounders, to determine associations of the combination of ALT and GGT levels and obesity with DM prevalence. RESULTS Overall, 6,008 participants (9.6%) had DM. Compared to non-obese individuals with low ALT and GGT levels, the participants with high ALT and GGT levels had high ORs for DM in both obese (OR 4.06; 95% CI, 3.61-4.56) and non-obese groups (OR 2.19; 95% CI, 1.89-2.52). The obese group had high ORs for DM, even at low ALT and GGT levels. CONCLUSION High ALT and GGT levels are associated with DM prevalence in obese and non-obese participants. This finding suggests that correcting ALT and GGT levels and controlling obesity are important for the prevention of DM.