Objective: Metabolic syndrome is a predictor of diabetes. Here, we examined the association of the number of metabolic syndrome components and their combinations with the development of type 2 diabetes.
Methods: Data for 19,475,643 participants ≥ 20 years old with no history of diabetes were obtained from the Korean National Health Insurance Service-National Sample Cohort between 2009 and 2012. Metabolic syndrome was defined according to the modified criteria of the National Cholesterol Education Program Adult Treatment Panel III. Diabetes risk over a five-year period was estimated with Cox proportional hazards models.
Results: The multivariable-adjusted hazard ratios (HRs) for the incidence of type 2 diabetes in one through five components were 1.40, 1.86, 2.47, 3.16, and 4.50, respectively, compared with the absence of components. The risk of developing diabetes was 1.835-fold higher for the presence of metabolic syndrome than its absence and 1.821-fold for elevated fasting glucose component than its absence. Combinations that included elevated fasting glucose were associated with a significantly higher risk of developing diabetes than not. In addition, the strongest combination for diabetes risk among three components was elevated fasting glucose, elevated triglycerides, and reduced HDL cholesterol compared with no component (HR 3.342).
Conclusion: The number of metabolic syndrome components and their combinations were associated with an increased risk of developing diabetes. Elevated fasting glucose is the most robust predictor of type 2 diabetes. Moreover, combinations that included elevated triglycerides and reduced HDL cholesterol showed a stronger combinatorial effect.