Incidence and predictors of type 2 diabetes among Koreans: A 12-year follow up of the Korean Genome and Epidemiology Study

Abstract

Aim: Because the incidence of type 2 diabetes in Korea has not been clearly defined, we examined the incidence of this condition and its association with impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and other risk factors in a 12-year follow-up Korean community-based prospective cohort study.

Methods: We recruited 7542 subjects aged 40-69years without diabetes at baseline examination from the Korean Genome and Epidemiology Study and followed these subjects for 12years biennially. Diabetes was defined according to the 2010 American Diabetes Association criteria. The incidence of type 2 diabetes and the predictors of progression to diabetes were analyzed according to baseline glucose tolerance.

Results: The overall incidence of type 2 diabetes was 22.1 per 1000person-years. Subjects with combined IFG-IGT at baseline had the highest incidence of diabetes, which was more than two-fold that of individuals with isolated IFG or isolated IGT (114.4 vs. 51.3 vs. 53.1 per 1000person-years). A multivariate Cox proportional hazards model analysis showed that combined IFG-IGT, which were strong predictors of diabetes, as well as age, urban residence, family history of diabetes, smoking status, abdominal obesity, hypertension, high triglycerides and low HDL cholesterols were also independently associated with progression to diabetes.

Conclusions: The incidence of type 2 diabetes is relatively high in our Korean community-based sample. Combined IFG-IGT are strong predictors of type 2 diabetes. Measurement of 2-hour plasma glucose in addition to fasting plasma glucose is necessary for the detection of individuals at high risk for development of diabetes.

Keywords: Impaired fasting glucose; Impaired glucose tolerance; Incidence; Prediabetes; Type 2 diabetes.