Non-insulin-dependent diabetes in Nauruans: A comparison of newly and previously diagnosed cases

Summary A comparison of 148 newly diagnosed (‘incident’) and 202 previously diagnosed (‘prevalent’) Nauruan diabetics, examined during a population survey in 1982, has permitted cautious inference regarding the natural history of non-insulin-dependent diabetes (NIDDM) in this Micronesian population. As might be expected the results of the comparison do suggest that Nauruan diabetics undergo further deterioration in glucose tolerance, subsequent to diagnosis of the disease. Plasma glucose concentration is higher in prevalent than incident cases (males: fasting — 12.2 versus 10.4 mmol/l; 2 h — 18.9 versus 16.3 mmol/l; and females: fasting — 13.1 versus 9.3 mmol/l; 2 h — 20.3 versus 15.8 mmol/l) suggesting that present treatment measures may not be effective in this population. There was also some evidence that the metabolic consequences of NIDDM may be greater in female than in male Nauruans. Apart from plasma glucose concentration, of 8 other biological variables examined by univariate and multiple logistic regression analysis, three showed consistent differences between incident and prevalent cases in females, but none were consistently different in males. A relatively small difference in estimates of obesity was observed between incident and prevalent cases, and this was particularly notable in males. A number of potential sources of bias in this study are highlighted, and definitive, longitudinal studies will be required to corroborate these findings.