The liver is the site of production of glucose and plays an important role in glucose homostatsis. Impaired liver function has been shown to be associated with incident diabetes. The independent role of the different liver enzymes, including γ-glutamyltransferase (GGT), alanine transaminase (ALT) and aspartate transaminase (AST), has not been addressed properly; therefore we decided to determine the association between liver enzymes and risk of diabetes in newly diagnosed and treated patients in Azar cohort population

In the present study, the data of 14997 subjects who participated in Azar cohort study were cross-sectionally analyzed. Subjects with fasting blood glucose ≥126 mg/dl or use of glucose lowering medication with a history of diabetes were considered as diabetic. Serum AST, ALT, alkaline phosphates ALP and GGT were determined by kits. The associations of serum liver markers with diabetes were analyzed using logistic regression models.

Of total, 2097 subjects (14%) are diabetic (2.4 % newly diagnosed). We found that with increasing levels of liver enzymes (ALP, ALT, GGT), the risk of diabetes is also increased (P<0.05). Moreover, this association is significant after adjustment for age, BMI and gender (P<0.001). The highest odds ratio (OR) is observed in 4 th quartiles serum GGT (≥29 IU/l) which increased the chance of diabetes 6.9 and 2.78 in newly diagnosed and with history of diabetes patients respectively (P<0.01). Serum AST and AST/ALT ration are negatively correlated with diabetes in patients treated with glucose lowering medication.

The findings of present study indicated that predictive power of liver enzymes (especially GGT) for risk of diabetes in newly diagnosed diabetic patients are higher than diabetic patients treated with medications. The GGT level appeared to be the most significant risk for diabetes, however, further studies are needed to confirm our findings and clarify the underlying mechanisms. On the other hand, it is suggested that liver enzymes in all diabetic patients should be checked as patients with type II diabetes have a markedly increased risk of developing non-alcoholic steatohepatitis and cirrhosis and even hepatocellular carcinoma.