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Objective To determine the current prevalence of impaired glucose tolerance (IGT) and non‐insulin‐dependent diabetes mellitus (NIDDM) in Melanesians of three coastal Papua New Guinean communities, to relate this to previous studies, and to investigate plasma glucose distributions in these populations. Design Cross‐sectional survey, using 75 g oral glucose tolerance tests and World Health Organization criteria. Setting Rural Papuan villages of Wanigela and Kalo, and Wanigela people of the urban squatter settlement of Koki, Port Moresby. Subjects All adults aged 25 years or more living in the three communities were eligible, with response rates of 77.2% (Koki), 88.1% (Wanigela) and 72.5% (Kalo). 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. In Kalo both were uncommon. The prevalences of IGT and NIDDM in Koki had doubled over a 14‐year period. The age‐standardised prevalence of abnormal glucose tolerance in the Koki Wanigelas is the second highest in the world after the Arizona Pima Indians, and higher than in Micronesian Nauruans, even though the latter are more obese. Both fasting and two‐hour glucose concentrations in all age groups in Koki were clearly bimodal, a mixture of two log‐normal distributions. Conclusions The Wanigela people of Papua New Guinea have an extraordinary susceptibility to glucose intolerance which is exposed after adoption of modern lifestyle habits. A “founder effect” may explain the high frequency of a diabetogenic genotype in this population.

Eleven cases of cryptococcal meningitis were diagnosed and biotyped from September 1991 to August 1992 in Papua New Guinea (PNG). Seven isolates were Cryptococcus neoformans var. gattii from paediatric and adult patients, one with diabetes mellitus and 4 were C. neoformans var. neoformans from adults, of whom 2 had human immunodeficiency virus type 1 (HIV-1) infection, and one each had tuberculosis and Plasmodium vivax malaria. Significant clinical findings were headache, fever, meningism, vomiting, photophobia, papilloedema and cranial nerve lesions. Five patients (45.5%) died; 3 of these were adults with var. gattii and 2 were men with both var. neoformans and HIV-1 infections. This prospective tropical study documents the emergence of C. neoformans var. neoformans in patients with HIV-1 infection in a country where previously var. gattii had predominated in the immunocompetent. There has been no earlier report of cryptococcosis in an HIV-1 seropositive patient in PNG. Despite presumed exposure to both varieties of C. neoformans, var. gattii infections had been most frequent. As HIV-1 spreads, the proportion of hosts infected with var. neoformans may rise. The course of meningitis caused by the 2 varieties of C. neoformans may differ, with mortality in the tropics remaining particularly high. In PNG the environmental source of C. neoformans remains elusive.

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OBJECTIVE--To study the association between diet and newly diagnosed NIDDM in the Wanigela people of Papua New Guinea, a population with an extraordinary susceptibility for NIDDM. RESEARCH DESIGN AND METHODS--We performed a case-control study of Wanigela people from an urban settlement (Koki). Case patients (n = 145) were asymptomatic subjects in whom NIDDM was newly diagnosed using a 2-h 75-g oral glucose tolerance test. Control subjects with glucose tolerance (n = 140) were group-matched on the basis of age and sex. A detailed food frequency questionnaire was used to determine energy and nutrient intakes. Nutrient intakes were compared directly and after calculation of residuals to correct for energy intake. Odds ratios for NIDDM were computed in relation to total energy and specific nutrient intakes, adjusting for age, sex, BMI, waist-to-hip ratio, and physical activity. RESULTS--There were no differences between case patients and control subjects in mean values of total energy-adjusted nutrient intakes. In logistic regression models, neither total energy nor any specific nutrients were associated with increased risk of NIDDM. When models were repeated with nutrients categorized by textiles, there were marginally significant associations with intakes of fiber (positive) and cholesterol, protein, and sugar (negative). CONCLUSIONS--This study does not support the hypothesis that saturated fat is an independent risk factor for NIDDM. The weak associations of intakes of fiber and cholesterol with newly diagnosed NIDDM were in the opposite directions to those expected and are probably due to chance. Relative homogeneity of diet within a community, such as that found in Koki, makes it difficult to demonstrate risk factor-disease associations. However, changes in diet and reduced levels of physical activity accompanying urbanization undoubtedly contribute to the high prevalence of obesity observed in this community, and hence diet is likely to contribute to NIDDM risk at least by indirect means.