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.

Dramatic increase in the prevalence of obesity in western Samoa over the 13 year period 1978-1991.

Obesity and an increasing prevalence of associated conditions such as diabetes and cardiovascular disease are frequently observed in Pacific populations as lifestyles become more modernized. In 1978, a survey conducted in three geographically defined populations in Western Samoa showed large differences in the prevalence of obesity (body mass index (BMI) > or = 30 kg/m2) between rural and urban populations. A follow-up survey using similar methods was performed in 1991 to examine the current level of obesity in these three locations and to assess changes over time. Cross-sectional differences in the prevalence of obesity, mean BMI and waist-hip circumference ratio (WHR) between urban Apia and rural Poutasi and Tuasivi were examined after adjusting for age. There were higher levels of obesity in urban vs rural areas: 74% of women in Apia were obese compared with 62% in Poutasi and 56% in Tuasivi. In men, comparable figures were 57%, 44% and 36% for Apia, Poutasi and Tuasivi respectively. Mean BMIs followed the same pattern. By contrast, WHR varied little between locations. Even in subjects aged 25-34 years, more than 50% of women in all locations, and 45% of urban men were obese. Increasing physical activity in men, but not women, was associated with lower mean BMI. Increasing education level and job status were associated with increasing BMI but these relationships were significant only in men. Multivariate analysis showed age, location (urban), occupation (high status, women), and in men, physical inactivity, to be independently associated with increased risk of obesity. Prevalence of obesity increased dramatically between 1978 and 1991 in all locations, but especially in Tuasivi, where in males the increase was 297% and in females 115%. There was a rightward shift in the distribution of body mass index in both sexes and all locations. These extreme increases in the prevalence of obesity, even in young adults, over the relatively short 13-year study period suggest an increasing burden of chronic diseases facing Western Samoa in the future, and emphasize the need for effective intervention to bring about lifestyle modification.

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.