Sex-specific associations of γ-glutamyltransferase to HDL-cholesterol ratio and the incident risk of cardiovascular disease: three Korean longitudinal cohorts from different regions

BACKGROUND: The combination of gamma-glutamyl transferase (GGT) and high-density lipoprotein cholesterol (HDL-C) (GGT/HDL-C) is a novel noninsulin-based marker for assessing the risk of nonalcoholic fatty liver disease and type 2 diabetes mellitus. However, whether the GGT/HDL-C ratio is related to the risk of incident cardiovascular disease (CVD) risk is not well known. Therefore, we aimed to investigate the longitudinal effect of GGT/HDL-C ratio on incident CVD risk in three large cohorts of Korean men and women. METHODS: Data were assessed from 27,643 participants without CVD from the Korean Genome and Epidemiology Study (KoGES), Health Risk Assessment Study (HERAS), and Korea Health Insurance Review and Assessment (HIRA) (HERAS-HIRA) datasets. The participants were divided into four groups according to the GGT/HDL-C quartiles. We prospectively assessed hazard ratios (HRs) with 95% confidence intervals (CIs) for CVD using multivariate Cox proportional-hazard regression models over a 50-month period following the baseline survey. RESULTS: During the follow-up period, 949 patients (3.4%; 529 men and 420 women) developed CVD. The HRs of CVD for GGT/HDL-C quartiles 2-4 were 1.36 (95% CI, 0.91–2.02), 1.54 (95% CI, 1.05–2.26), and 1.66 (95% CI, 1.12–2.47) after adjusting for metabolic parameters in women, but GGT/HDL-C did not show a trend toward increases in incident CVD in men. Regional discrepancies were evident in the results; the increase in HR in the metropolitan hospital cohort was more pronounced than that in the urban cohort, and the risk was not increased in the rural cohort. CONCLUSION: GGT/HDL-C ratio may be a useful predictive marker for CVD in women. Furthermore, the prevalence of CVD was strongly correlated with the GGT/HDL-C ratio in metropolitan areas, and this correlation was more significant than that observed with GGT or HDL-C in isolation.