High prevalence of diabetic retinopathy and nephropathy in Polynesians of Western Samoa.

OBJECTIVE: To determine the prevalence of diabetic retinopathy and nephropathy retinopathy and nephropathy and to define associated risk factors in Polynesian Western Samoans with non-insulin-dependent diabetes mellitus (NIDDM) or impaired glucose tolerance (IGT). RESEARCH DESIGN AND METHODS: A 1991 population-based study in Samoan adults (ages 25-74 years) included a 75-g oral glucose tolerance test, anthropometric measurements, and blood pressure recordings. Subjects with NIDDM or IGT had 45-degree stereo photographs taken (n = 263) (three standard fields of the right eye), and retinopathy was graded in comparison with Airlie House photographs. First-morning urine samples (n = 304) were also collected from these subjects and from a subsample with normal glucose tolerance. Urinary albumin concentration (UAC) was measured by radioimmunoassay: microalbuminuria was defined as UAC of 30-299 micrograms/ml; and macroalbuminuria among subjects with Proliferative diabetic retinopathy was found in 4.5% of known diabetic subjects. The prevalence of elevated UAC was 15.0% in subjects with IGT, 26.0% in newly diagnosed diabetes subjects, and 23.4% in known diabetes subjects. For all diabetic subjects (n = 162), the factors independently associated with diabetic retinopathy (logistic regression) were duration of diabetes, fasting plasma glucose, and body mass index (inversely). Duration of diabetes, serum triglyceride concentrations, and systolic blood pressure were independently associated with elevated UAC in all diabetic subjects (n = 138), and fasting plasma glucose had borderline significance. CONCLUSIONS: Diabetic retinopathy and albuminuria are common in Polynesian Western Samoans. Duration of diabetes and level of glycemia were the most important associated factors. These data underline the need for cost-effective programs for the detection and early treatment of diabetes in Western Samoa and other developing populations with high susceptibility to NIDDM.

Increasing prevalence of NIDDM in the Pacific island population of Western Samoa over a 13-year period.

OBJECTIVE: A survey of noncommunicable diseases (NCD) in the Pacific island population of Western Samoa in 1978 (n = 1,206) documented a relatively high prevalence of non-insulin-dependent diabetes mellitus (NIDDM) and obesity. A follow-up survey was performed in 1991 (n = 1,776) to assess changes in NCD prevalence and risk factor distribution over 13 years. RESEARCH DESIGN AND METHODS: In both surveys, the same representative villages from one urban and two rural areas were studied, and the survey procedure included an oral glucose tolerance test, anthropometric and blood pressure measurements, and physical activity assessment (1991 only). RESULTS: The age-standardized prevalence of NIDDM in 1991 was 9.5 and 13.4% in Apia (urban) for men and women, respectively. In Poutasi (rural), 5.3% of men and 5.6% of women had NIDDM, and in Tuasivi (rural) the prevalence was 7.0 and 7.5% for men and women, respectively. Age, body mass index (BMI), waist-to-hip circumference ratio, physical inactivity, and family history of diabetes all showed independent association with NIDDM and impaired glucose tolerance. Living in Apia (compared with Poutasi) was also associated with NIDDM. Between 1978 and 1991, the age-standardized prevalence of NIDDM in Apia increased from 8.1 to 9.5% in men and 8.2 to 13.4% in women. In Poutasi, a dramatic increase occurred in prevalence from 0.1 to 5.3% in men, but little change in women was noted (5.4 to 5.6%). In Tuasivi, the increases were 2.3 to 7.0% in men and 4.4 to 7.5% in women. In combined survey areas, increases were observed in the age-standardized prevalence of obesity and mean levels of total cholesterol, fasting triglycerides, and uric acid between surveys as well as a reduction in the prevalence of smoking. CONCLUSIONS: This is the first study using standardized methods to show a dramatic increase in the prevalence of NIDDM in a developing Pacific island population, and it indicates the importance of maintaining and expanding preventive programs for NIDDM and related lifestyle diseases in these populations.