Fasting plasma glucose and incidence of diabetes --- implication for the threshold for impaired fasting glucose: results from the population-based Omiya MA cohort study.

AIM

In 2003, the American Diabetes Association recommended that the threshold for diagnosing impaired fasting glucose (IFG) should be lowered from 6.1 mmol/L (110 mg/dL) to 5.6 mmol/L (100 mg/dL). To discuss the diagnostic threshold for IFG, the association between fasting plasma glucose (FPG) and the risk of future diabetes must be known; however, data regarding this relation in the Japanese population are scarce. The aim of this study was to determine the relation between FPG and the risk of future diabetes in the Japanese general population.

METHODS

A retrospective cohort study was conducted using data from annual health check-ups performed in Omiya city. A total of 11,369 subjects between the ages of 40-79 years who were not diabetic at baseline were followed for seven years. Diabetes was defined as FPG > or =126 mg/dL or self-report.

RESULTS

The incidence of diabetes increased as the baseline FPG level increased and a similar pattern was observed irrespective of sex or age. The hazard ratios compared with subjects with FPG <85 mg/ dL adjusted for possible confounding factors were 3.83 (95% confidence interval (95% CI); 2.41-6.08) for subjects with 100 to 104 mg/dL FPG and 7.87 [corrected] (95% CI; 4.98-12.4) for subjects with 105 to 109 mg/dL FPG.

CONCLUSIONS

Subjects with 100-109 mg/dL FPG have an appreciable risk of diabetes that cannot be considered as "normal" and should be notified of their potential risk of developing diabetes.