EPIDEMIOLOGICAL INVESTIGATION OF INSULIN RESISTANCE SYNDROME (SYNDROME X) IN A CITY IN JAPAN

Summary 1. In order to study the prevalence of insulin resistance syndrome (syndrome X) in Japanese subjects, inhabitants aged above 40 years living in Osaka-Sayama city from September 1992 through December 1993 were investigated. The population-based study was performed on 2498 subjects (661 males and 1837 females) constituting 10.9% of the total population aged above 40 years. 2. The prevalence of glucose intolerance was 8.7% (n= 218) in 2498 subjects. The prevalence of hypertension was 36.9% (n= 923) and that of hypertriglyceridaemia was 19.0% (n= 475). The prevalence of syndrome X as characterized by an association of glucose intolerance, hypertension and hypertriglyceridaemia was 1.6% (n= 39) in all subjects examined and 17.4% in subjects showing glucose intolerance. 3. Fasting serum insulin levels were significantly higher in patients with syndrome X than in normal subjects. Furthermore, the levels were significantly correlated with blood levels of frucutosamine, fasting glucose and triglyceride, and with body mass index as well. 4. In conclusion, insulin resistance syndrome (syndrome X) is also found among the larger Japanese population, and fasting serum insulin levels can be a useful marker of this metabolic disorder.