Prevalence of diabetes mellitus and impaired glucose tolerance in Aborigines and Chinese in eastern Taiwan.

The aim of this study was to determine the prevalence of diabetes mellitus and impaired glucose tolerance (IGT) in three different ethnic groups in eastern Taiwan. The study was performed among Han Chinese, aboriginal Ami and aboriginal Atayal in six rural villages. Inhabitants aged 40 years and over were invited to participate. A 75-g oral glucose tolerance test (OGTT) was used as suggested by the World Health Organization (WHO) for population screening purposes. WHO criteria were used for determining the results. A total of 1013 adults (460 men and 553 women) were examined with a response rate of 62.1%. There were no significant differences in sex, age and history of diabetes between responders and non-responders. The age-adjusted prevalence of diabetes was 11.0% (9.8% in men and 12.3% in women) in the Chinese, 9.1% (12.1% in men and 7.4% in women) in the Amis, 10.8% (11.5% in men and 9.4% in women) in the Atayal and 9.9% (11.5% in men and 8.5% in women) for the two aboriginal groups together. Although sex differences in prevalence of diabetes were not statistically significant, it seems that diabetes was slightly more prevalent in Chinese women than in Chinese men (12.3 versus 9.8%). Nonetheless, the prevalence rate of diabetes was somewhat higher in the aboriginal males than in the aboriginal females (12.1 versus 9.8% for Ami and 11.5 versus 10.7% for Atayal). The prevalence of IGT was 7.2, 8.5, 10.8 and 9.7% for the Chinese, Amis, Atayal and the two aboriginal groups, respectively. There were no substantial differences in the prevalence of diabetes and IGT among these three ethnic groups. Environment, rather than ethnicity, was more likely the predominant factor. It was found that the prevalence of diabetes in this study was about twice as high as that reported in a 1987 survey in Taiwan. The discrepancy may be due to different screening methods and assessment periods.