Objective: We investigated whether gamma-glutamyltransferase (GGT) variability can predict the risk of stroke, myocardial infarction (MI), and all-cause mortality in individuals with diabetes.
Methods: The study subjects were Koreans with diabetes who had undergone health examinations provided by the Korean National Health Insurance Corporation more than once during 2009-2012 (baseline). After excluding subjects aged <40 years and those with histories of stroke, MI, chronic liver disease, or drinking ≥30g/day of alcohol, a total 698937 individuals were included. As a parameter of variability, we calculated the average successive variability (ASV) of GGT values measured during the five years before the baseline exam. We estimated the risk of stroke, MI, all-cause mortality according to GGT ASV quartiles using multivariate-adjusted Cox analyses, until December 31, 2016. Stroke and MI was defined using ICD-10 codes (I63-I64 and I21-I22) and admission record.
Results: During follow-up period, 26119 cases of stroke, 15103 cases of MI, and 39982 cases of death were identified. GGT ASV quartile showed significantly higher risk of stroke and all-cause mortality compared with quartile 1, even after adjustment for age, sex, renal function, obesity, drinking, smoking, exercise, presence of hypertension and dyslipidemia, hemoglobin, income status, glucose and GGT level, duration of diabetes, the number of histories of oral antidiabetic medication, prescription history of insulin, presence of diabetic retinopathy and peripheral artery disease. The fully adjusted HRs (95% CIs) of GGT ASV quartiles 4 were 1.06 (1.03-1.10) and 1.23 (1.20-1.27), respectively. This significance was maintained regardless of baseline GGT quartile in all-cause mortality.
Conclusions: GGT variability was associated with the risk of all-cause mortality and stroke. This tendency is most pronounced in all-cause mortality, regardless of baseline GGT levels.
D. Lee: None. J. Yu: None. K. Han: None. J. Seo: None. N. Kim: None.
National Research Foundation of Korea