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.