Incidence of Type 2 Diabetes is Higher among Men with Persistent Impaired Glucose Tolerance than in Transient Impaired Glucose Tolerance - A 5 year Follow up Study.

OBJECTIVE: This was a 5 year comparative analysis of the incidence of type 2 diabetes in men who had persistent impaired glucose tolerance (P-IGT) versus transient impaired glucose tolerance (T-IGT). P-IGT (positive IGT on two oral glucose tolerance tests (OGTT), T-IGT (IGT in first OGTT and normal glucose tolerance (NGT) in the 2nd OGTT). METHODS: The samples were collected from a randomized controlled diabetes prevention study. The prevention study was done using lifestyle modification (LSM) promoted by use of mobile short message services (SMS) for 2 years. The control group of the randomized study who received advice on LSM at only the baseline formed the P-IGT group for the 3 years follow up study (n=236). T-IGT (n=569) were available from those who had NGT on the 2nd OGTT while screening for the prevention study. The total diabetes incidence at 5 years in the study groups were compared using standard OGTT (WHO criteria). RESULTS: The conversion rate to diabetes in 5 years was significantly lower among T-IGT than among P-IGT, OR=0.202 (95% CI, 0.145-0.296,p< 0.0001). P-IGT had higher rate of risk factors for diabetes than T-IGT. CONCLUSION: The risk of conversion to diabetes was 80 percent lower in T-IGT than in P-IGT. Identification of P-IGT will help in selecting persons who require early intervention for diabetes.