Gamma-glutamyltransferase activity and development of the metabolic syndrome (IDF definition), in middle-aged men and women: the D.E.S.I.R. cohort

Abstract

Objective-- Among hepatic enzymes, gamma-glutamyltransferase (GGT) is the main predictor of type 2 diabetes incidence, although it has not been shown that GGT predicts pre-diabetic states. Our aim was to study the association of GGT with the development of the metabolic syndrome (MetS).

Research Design and Methods-- We analysed the 3-year data from the D.E.S.I.R. prospective cohort of 1656 men and 1889 women without baseline MetS, according to the International Diabetes Federation definition.

Results-- Over the 3-years, 309 participants developed the MetS. After adjustment for age, alcohol intake, physical activity, smoking habits and alanine-aminotransferase (ALT), the odds ratios (OR) for incident MetS increased across baseline GGT quartiles: 1, 1.96, 2.25, 3.81 in men (P<0.03); and 1, 1.23, 1.80, 1.58 in women (P<0.05). After additional adjustment for insulin resistance markers (fasting insulin or HOMA-IR index) the association was attenuated and the linear relation was no longer significant in both sexes (P=0,08, P=0,16) . However, men in the highest in comparison to the lowest quartile of GGT retained a significant risk for incident MetS. In women there was no longer a significant risk. GGT was significantly associated with the 3-year incidence of individual components of the MetS. The incidence of the MetS also increased with ALT, but after adjustment on GGT, this association remained significant only in women.

Conclusions-- GGT, a predictor of type 2 diabetes, was associated with a risk of incident MetS. This association was mainly related with insulin resistance but was independent of other confounding factors.