[Prevalence of glucose intolerance, diabetes mellitus, and high serum insulin levels in a Japanese urban population].

An epidemiological study was conducted to investigate the prevalence of diabetes mellitus, glucose intolerance and hyperinsulinemia in an urban population. Twelve thousand two hundred people aged 30 to 79 were randomly selected from residents of S-city in Osaka Prefecture and were urged to attend a cardiovascular examination at the National Cardiovascular Center. In 1992 and 1993, among 5,284 people who received the examination, 75 g oral glucose tolerance tests (OGTT) were performed and plasma glucose and serum insulin concentrations were determined for 2,147 subjects, who participated in the morning course of examination and who were fasting. The prevalence of diabetes and hyperinsulinemia (fasting serum insulin level > or = 15 microU/ml) was higher in older than in the younger generation, and was higher in men than in women. The prevalence of diabetes in those aged 40 and over in S-city was 7.3% in men and 5.6% in women, 17.2% of men and 10.7% of women had impaired glucose tolerance, and 7.5% of men and 5.2% of women had hyperinsulinemia. A comparison of prevalences of diabetes was performed between 4 populations, one being our urban population and others being 3 rural populations where population-based surveys had been accomplished with OGTT but without a screening as ours was with regard to detecting diabetes. The prevalence of diabetes in our urban population did not appear to be higher than in the other 3 rural populations. From a questionnaire survey of responders and non-responders to OGTT, it was considered that the degree of selection bias in this study was small, if any.