Serum gamma-glutamyl transferase within its normal concentration range is related to the presence of impaired fasting glucose and diabetes among Japanese community-dwelling persons.

INTRODUCTION. Serum gamma-glutamyl transferase (GGT) activity changes in response to oxidative stress. Little data are available on the association between serum GGT and the prevalence of impaired fasting glucose (IFG) and diabetes among Japanese community-dwelling persons. METHODS. We recruited 871 men, aged 61 ± 14 (range, 20-89) years, and 1,139 women, aged 63 ± 12 (range, 21-88) years during their annual health examination from a single community. We performed a cross-sectional study to examine whether serum GGT was associated with IFG and diabetes. RESULTS AND CONCLUSIONS. The levels of most confounding characteristics varied with increasing GGT activity. The prevalence of IFG and diabetes was significantly and linearly associated with increasing quartiles of serum GGT. After adjustment for sex, age, smoking status, drinking status, low-density lipoprotein cholesterol, uric acid, estimated glomerular filtration rate, and alanine aminotransferase, the odds ratio (OR) [95% confidence interval (CI)] for IFG compared with the participants with lowest quartile of serum GGT was 1.91 (1.31-2.78) for second quartiles, 2.41 (1.63-3.57) for third quartiles, and 3.24 (2.03-5.17) for highest quartiles. The multivariate-adjusted OR (95% CI) for diabetes was 1.91 (1.18-3.09) for second quartiles, 2.15 (1.30-3.54) for third quartiles, and 3.79 (2.11-6.82) for highest quartiles. Furthermore, the multivariate-adjusted ORs for IFG were also associated with increasing levels of serum GGT within subgroups of age, body mass index, drinking status, serum high-molecular-weight adiponectin levels, insulin resistance, and the presence of antihypertensive/antilipidemic medication. These results suggested that higher serum GGT within normal concentration range was significantly associated with IFG and diabetes in the general population.