Studies on 75g oral glucose tolerance in the inhabitants of Kumamoto Prefecture, Japan.

Abstract

The authors assessed the prevalence of diabetes mellitus (DM) and impaired glucose tolerance (IGT) according to the 1980 National Diabetes Data Group (1980 NDDG) classification and diagnosis. Two hundred and sixty inhabitants [aged 50.9 +/- 9.6 years, male: female (M:F) = 90: 170] of five small rural towns in Kumamoto Prefecture (population 1.8 million) and 279 male members of western divisions of the Japanese Ground Self Defence Forces (SDF employees) living in Kumamoto, who had retired at the age 50 years were subjected to the 75 g oral glucose tolerance test (75 g OGTT) in association with routine clinical and laboratory examinations. In addition, the results of 50 g OGTT obtained in 1243 SDF members (aged 50 years, male) from 1977 to 1980 were included in this study, after their blood glucose concentrations were converted to those of 75 g OGTT according to the 1982 recommendations of the Japan Diabetic Society. The overall prevalence of DM was 2.7%, IGT 17%. Out of the 10 subjects found to have DM in the inhabitants of the 5 rural towns, 6 (M:F = 3:3) were 60 years of age or over and half of them were aware of their diabetes mellitus. None of the 8 cases of DM discovered among the SDF employees examined in 1981-1982 had any signs or symptoms of DM, whereas 3 were hypertensive, 2 were markedly obese and 4 were hypertriglyceridemic.