Gamma-Glutamyl Transferase and the Risk of Type 2 Diabetes Mellitus: A Review

The relationship between gamma-glutamyl transferase (GGT) levels and risk factors for type 2 diabetes mellitus (T2DM) and the risk of incident T2DM was assessed using a narrative review of available evidence. Higher circulating levels of GGT are associated with an increased risk of type 2 diabetes mellitus, suggesting GGT as a risk predictor of T2DM. The incidence of type 2 diabetes and its association with GGT elevation could be explained by oxidative stress in cells followed by subclinical inflammation and fatty liver, leading to impaired insulin secretion and insulin resistance. A strong correlation is evident between BMI and GGT, in which hepatic steatosis and insulin resistance are proposed to be the intermediate connecting characteristics.