Association of liver enzymes with incident diabetes in US Hispanic/Latino adults

Introduction: Non-alcoholic fatty liver disease (NAFLD) has been associated with increased risk of incident diabetes. But such evidence is lacking in the Hispanic/Latino population, which has high prevalence of obesity and NAFLD. Methods: We conducted a prospective cohort study of 6,928 adults of Hispanic/Latino background who had no diabetes, did not report excessive alcohol use, and no hepatitis B and C infection at baseline (2008–2011). We estimated risk ratios (RR) for incident diabetes, identified from visit 2 examination by glucose measurements or antidiabetic medication use, with baseline liver enzymes (alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyl transpeptidase (GGT)). Results: A total of 738 adults developed diabetes during 6 years of follow-up. After adjusting for participant characteristics at baseline, versus the lowest quartile, highest quartiles of ALT and GGT were associated with risks for incident diabetes (RR for ALT: 1.51 [95% CI 1.03–2.22], p-trend = 0.006; RR for GGT: 2.39 [1.60–3.55], p-trend = 0.001). Higher GGT levels predicted increased risk of incident diabetes even among those with ALT or AST below the median levels. The associations of ALT and GGT with incident diabetes were similar among most Hispanic background but were not seen among Dominicans (p for interaction <0.05). The association of AST with incident diabetes was found only among light-to-moderate alcohol drinkers (RR = 1.50 [1.20–1.86]) but not abstainers (RR = 0.91 [0.69–1.20], p for interaction = 0.006). Conclusion: Higher ALT and GGT levels are associated with increased risk of developing diabetes among Latinos. Liver enzyme tests might aid in diabetes prevention by identifying high-risk individuals.