Glucose intolerance is predicted by the high fasting insulin-to-glucose ratio

Objective: To determine whether impaired glucose tolerance (IGT) is predict ed by high Fasting insulin-to-Glucose (FIG) ratio and to establish its corr elation with insulin resistance and fasting insulin. Material and Methods: A population-based three-year follow-up study was per formed. The target population consisted of healthy volunteers, men and non- pregnant women aged 30 years or over. Participants were required to have no rmal referenced ranges of OGTT and blood pressure. Previous diagnosis of ch ronic diseases was an exclusion criterion. At baseline and at the 3-yr of f ollow-up, an OGTT was performed. The ratio of serum Fasting insulin (mu Ul/ ml)/Fasting Glucose (mg/dl) was used to calculate the FIG ratio. Insulin ac tion and secretion were estimated by HOMA and Insulinogenic index, respecti vely. Results: The FIG ratio was directly correlated with the HOMA index (r = 0.8 3, p <0.01) and fasting insulin (r = 0.95, p < 0.001). Multivariate logisti c regression analysis showed that IGT was more likely to develop in subject s with high FIG ratio (RR 5.01; CI95% 1.9-12.2, p = 0.02), high HOMA index (RR 6.1; CI95% 2.1-11.1, p = 0.01), and fasting hyperinsulinemia (RR 4.7 CI 95% 2.7-13.2, p < 0.05). The cutoff point of FIG ratio far determining the risk of developing IGT was 0.25 +/- 0.05. Conclusions: The FIG ratio could be a reliable alternative for the screenin g of apparently healthy subjects in high risk groups.