Background: Metabolic syndrome (MetS) is associated with an increased risk of diabetes. In this study, we aimed to investigate the incidence rate of type 2 diabetes according to the number of MetS components using data from the Korean National Health Insurance Service-National Sample Cohort (NHIS-NSC).
Methods: A total of 24,582,108, aged 20 years or older, with no history of diabetes were recruited between 2009 and 2012. MetS components were defined using the modified criteria of the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III). Type 2 diabetes was defined as a current medication history of antidiabetic drugs and the presence of International Classification of Diseases (ICD)-10 codes (E11-E14) as diagnosis.
Results: The number of MetS components gradually increased with increasing age. Over a total of 118,311,497.11 person-years of follow-up, 658,934 subjects were diagnosed with type 2 diabetes. The multivariable-adjusted hazard ratios for incident diabetes for the number of MetS components were 2.54, 4.83, 7.92, 11.78 and 20.94 for one, two, three, four or five components, respectively, compared with the absence of components. The risk of diabetes with regard to each component of MetS was 1.76 for high fasting plasma glucose, 1.44 for high blood pressure, 1.19 for central obesity, 1.17 for high triglycerides, and 1.15 for low HDL cholesterol. The combinations that included high fasting plasma glucose level appeared to be more strongly associated with the risk of diabetes than other combinations with the same number of MetS components.
Conclusions: The risk of diabetes gradually increased with the increasing number of MetS components. Among the components, hyperglycemia was the most powerful predictor of diabetes. Our findings indicate that the risk stratification of individuals by the number of MetS components and hyperglycemia status can detect individuals with a high risk of diabetes.
M. Lee: None. H. Kwon: None.