Increased Risk of Diabetes Development in Subjects with the Hypertriglyceridemic Waist Phenotype: A 4-Year Longitudinal Study

BACKGROUND The hypertriglyceridemic waist (HTGW) phenotype is a simple and inexpensive screening parameter to identify people at increased risk of cardiovascular disease. We evaluated whether the HTGW phenotype predicts diabetes in urban Korean adults. METHODS A total of 2,900 nondiabetic subjects (mean age 44.3 years), comprising 2,078 males (71.7%) and 822 females (28.3%) who underwent annual medical check-ups at our center between January 2005 and December 2009, were recruited. The subjects were divided into four groups according to baseline serum triglyceride (TG) level and waist circumference (WC): normal WC-normal TG (NWNT) level, normal WC-high TG level, enlarged WC-normal TG level, and enlarged WC-high TG (EWHT) level. High serum TG level was defined as ≥150 mg/dL and enlarged WC was defined as ≥90 cm for men and ≥85 cm for women. New cases of diabetes were determined according to questionnaires filled in by participants and the diagnostic criteria of the American Diabetes Association. Cox proportional hazards model analysis was used to assess the association of HTGW phenotype with the incidence of diabetes. RESULTS A total of 101 (3.5%) new diabetes cases were diagnosed during the study period. The EWHT group had a higher incidence of diabetes (8.3%) compared with the NWNT group (2.2%). The adjusted hazard ratio for diabetes for subjects with the EWHT phenotype at baseline was 4.113 (95% confidence interval [CI], 2.397 to 7.059) after adjustment for age, and 2.429 (95% CI, 1.370 to 4.307) after adjustment for age, sex, total cholesterol, systolic blood pressure, and alcohol drinking history. It was attenuated by inclusion of baseline fasting glucose level in the model. CONCLUSION Subjects with the HTGW phenotype showed the highest risk of incident diabetes. This tool could be useful for identifying individuals at high risk of diabetes.