Normal fasting plasma glucose and risk of type 2 diabetes.

OBJECTIVE: To investigate the association of normal fasting plasma glucose (FPG) and the risk for type 2 diabetes.

RESEARCH DESIGN AND METHODS: Data concerning 13,845 subjects, aged 40-69 years, who had their FPG measured at least three times between 1992 and 2008 were extracted from a database. Three FPG groups were defined (51-82, 83-90, and 91-99 mg/dL). A Cox proportional hazards analysis was applied to estimate the risk of incident diabetes adjusted for other risk factors.

RESULTS: During 108,061 person-years of follow-up (8,110 women and 5,735 men), 307 incident cases of type 2 diabetes were found. The final model demonstrated a hazard ratio of 2.03 (95% CI 1.18-3.50) for 91-99 mg/dL and 1.42 (0.42-4.74) for 83-90 mg/dL.

CONCLUSIONS: Our data suggest that FPG between 91 and 99 mg/dL is a strong independent predictor of type 2 diabetes and should be used to identify people to be further investigated and aided with preventive measures.