[Gamma]-Glutamyltransferase Is a Predictor of Incident Diabetes and Hypertension: The Coronary Artery Risk Development in Young Adults (CARDIA) Study (Lipids, Lipoproteins, And Cardiovascular Risk Factors) (Clinical Report‪)‬

Serum [gamma]-glutamyltransferase (GGT), (8) even within reference intervals, is associated with several cardiovascular disease risk factors and components of the insulin resistance syndrome (1-3). In addition, in several prospective studies (4-10), the baseline serum GGT concentration has been ac independent risk factor for the development of cardiovascular or cerebrovascular diseases. In our previous prospective studies in healthy Korean men (10), serum GGT concentrations within the reference interval showed a strong dose-response relationship with incident diabetes. This strong relationship was observed even in nondrinkers and individuals without increased concentrations of any other liver enzymes. Therefore, although GGT has been widely used as a marker of alcohol consumption or liver disease (11), neither alcohol nor hepatic dysfunction explained the observed relationships between GGT and diabetes. GGT is also a modest risk factor for hypertension (9). Therefore, the mechanism underlying these observations is not fully understood. An interesting ancillary observation is that the well-known strong association of either obesity or age with diabetes was observed only among individuals with high-normal GGT at baseline (10).