Liver enzymes, alcohol consumption and the risk of diabetes: the Suita study

Aim: We aimed to investigate the combined impact of liver enzymes and alcohol consumption on the diabetes risk. Methods: Data on 5972 non-diabetic participants aged 30–79 years from the Suita study were analyzed. Diabetes incidence was surveyed every 2 years. Current daily alcohol consumption was defined as light drinking (< 23.0 g ethanol/day in men and < 11.5 g in women), moderate drinking (23.0–45.9 g and 11.5–22.9 g), and heavy drinking (≥ 46.0 g and ≥ 23.0 g). The nondrinkers category included both never-drinkers and former drinkers. Results: During the median follow-up of 13 years, 597 incident diabetes cases were diagnosed. Higher levels of γ-glutamyltransferase (GGT), alanine aminotransferase (GPT), and aspartate aminotransferase (GOT) were associated with an increased diabetes risk, and current light drinkers had a lower risk of diabetes than nondrinkers. No sex differences were observed in these associations. Compared to nondrinkers having the lowest quartiles of liver enzymes, nondrinkers and current moderate/heavy drinkers having the highest quartiles had an increased risk of diabetes. However, no association was observed for current light drinkers having the highest quartiles of liver enzymes; the multivariable hazard ratios (95% CIs) in current light drinkers with the highest quartile of liver enzymes were 1.27 (0.68–2.37) for GGT, 1.05 (0.59–1.89) for GPT, and 0.76 (0.40–1.47) for GOT, respectively. Conclusion: High liver enzymes were associated with an increased diabetes risk. No increased diabetes risk was observed in current light drinkers, even in these who had high levels of liver enzymes.