Prevalence and risk factors for diabetes: a ten year follow-up study of the Yaeyama district of Okinawa.

To clarify the prevalence and incidence of diabetes and to evaluate which risk factors are predictive of future diabetes in the general population of Okinawa, 1,690 residents were screened in 1989 and 758 were prospectively followed-up in 1999. Of the 1,690 residents surveyed in 1989 and 1, 163 in 1999, diabetes was found in 91 (5.4%) in 1989 and 52 (4.5%) in 1999. Residents with diabetes were significantly older, more likely to have significantly higher levels of HbA1c, fasting glucose, serum triglyceride, ALT, BMI, systolic blood pressure, and a history of hypertension than non diabetic residents, both in 1989 and 1999. 717 residents who did not have diabetes at the 1989 screening were re-examined in 1999. Among them, 17 (incidence rate 2.4%) had developed diabetes over the ten years. Multivariate logistic regression analysis showed HbA1c, BMI, and systolic blood pressure to be independent risk factors for newly developed diabetes (p < 0.0001, odds ratio; 28.1, p = 0.020, odds ratio; 1.21, p = 0.039, odds ratio; 1.04, respectively) after adjusting for age, sex, BMI, blood pressure, hystory of hypertension, HbA1c, fasting glucose, serum triglyceride, ALT, and y GTP. Our results showed that the prevalence and incidence of diabetes are low in the general population of the Yaeyama district of Okinawa and that elevated HbA1c level, even in the normal range, is one of the best predictors of diabetes. Following BMI and systolic blood pressure is important.