Impaired fasting glucose and impaired glucose tolerance - lack of agreement between the two categories in a North Indian population

This study was carried out to determine the relationship between impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) in a North Indian population. The data in 5083 subjects studied earlier was reanalyzed by applying new WHO diagnostic criteria. Reanalysis revealed that 305 (6.0%) subjects had diabetes mellitus (198 on the basis of fasting plasma glucose of > or =7.0 mmol/l (> or =126 mg/dl) and an additional 107 based on a 2-h glucose tolerance test), 381 (7.5%) had IFG and 361 (7.1%) had IGT. Of these 361 subjects with IGT, only 99 (27.4%) had impaired fasting glucose whereas 262 (72.6%) had normal fasting glucose of <6.1 mmol/l (<110 mg/dl). Of 381 subjects with IFG, 99 (26%) had IGT where as 282 (74%) had normal 2-hr glucose. We conclude that there is a poor correlation between IGT and IFG.