EXTRAORDINARY PREVALENCE OF NON-INSULIN-DEPENDENT DIABETES-MELLITUS AND BIMODAL PLASMA-GLUCOSE DISTRIBUTION IN THE WANIGELA PEOPLE OF PAPUA-NEW-GUINEA

Objective: To determine the current prevalence of impaired glucose tol erance (IGT) and non-insulin-dependent diabetes mellitus (NIDDM) in Me lanesians of three coastal Papua New Guinean communities, to relate th is to previous studies, and to investigate plasma glucose distribution s in these populations. Design: Cross-sectional survey, using 75g oral glucose tolerance tests and World Health Organization criteria. Setti ng: Rural Papuan villages of Wanigela and Kalo, and Wanigela people of the urban squatter settlement of Koki, Port Moresby. Subjects: All ad ults aged 25 years or more living in the three communities were eligib le. with response rates of 77.2% (Koki), 88.1% (Wanigela) and 72.5% (K alo). Main outcome measures: Prevalence of abnormal glucose tolerance, risk factor levels, fasting and two-hour plasma glucose concentration . Results: Age-standardised prevalence of NIDDM in Koki Wanigelas was 27.5% in men and 33.0% in women; an additional 20.5% of men and 22.0% of women had IGT. Even in the youngest age group (25-34 years), 36.5% of subjects had abnormal glucose tolerance. The overall prevalences of NIDDM and IGT in rural Wanigelas were 11.7% and 17.0% respectively. I n Kalo both were uncommon. The prevalences of IGT and NIDDM in Koki ha d doubled over a 14-year period. The age-standardised prevalence of ab normal glucose tolerance in the Koki Wanigelas is the second highest i n the world after the Arizona Pima Indians, and higher than in Microne sian Nauruans, even though the latter are more obese. Both fasting and two-hour glucose concentrations in all age groups in Koki were clearl y bimodal, a mixture of two log-normal distributions. Conclusions: The Wanigela people of Papua New Guinea have an extraordinary susceptibil ity to glucose intolerance which is exposed after adoption of modern l ifestyle habits. A ''founder effect'' may explain the high frequency o f a diabetogenic genotype in this population.