Gamma-glutamyltransferase and cardiovascular mortality in Korean adults: A cohort study

Insufficient evidence has been reported on the associations between gamma-glutamyltransferase (GGT) and cardiovascular disease (CVD) mortality from studies with an adequate number of participants.

512,990 Korean adults who participated in routine health examinations during the period 2002-2003 were followed up until 2013. Hazard ratios (HRs) were calculated after adjusting for potential confounders.

Each 1-unit higher natural-log-transformed GGT (Log_eGGT) level was associated with approximately 30-50% higher mortality risk of CVD (HR = 1.31): hypertensive diseases (HR = 1.31), ischemic heart diseases (IHD, HR = 1.29), total stroke (HR = 1.29), acute myocardial infarction (HR = 1.30), chronic IHD (HR = 1.27), heart failure (HR = 1.48), hemorrhagic stroke (HR = 1.42), and ischemic stroke (HR = 1.27). The associations with CVD mortality did not vary by sex, or alcohol use, whereas they were stronger in younger (<60 years), non-hypertensive (systolic blood pressure [SBP] <140 mmHg), physically more active, normal-weight (body mass index<25 kg/m²), and normocholesterolemic (total cholesterol <200 mg/dL) adults than in their respective counterparts. Adding Log_eGGT to prediction models for CVD mortality increased AUC value (0.0020, p < 0.001), especially in persons aged <60 years (0.0055), with SBP <140 mmHg (0.0030), and with both age <60 years and SBP <140 mmHg (0.0086).

Higher GGT significantly increased the risk of mortality due to CVD and its subtypes. The relative risks were greater in subjects with younger age, no hypertension, more physical activity, normal weight, and normocholesterolemia than in their respective counterparts. In the general population, adding GGT to conventional CVD risk factors may improve the prediction of CVD mortality, especially in subjects younger than 60 years and in those without hypertension.