Diabetes Care, Vol 18, Issue 8 1140-1149, Copyright © 1995 by American Diabetes Association
High prevalence of diabetic retinopathy and nephropathy in Polynesians of Western Samoa
VR Collins, GK Dowse, WE Plehwe, TT Imo, PM Toelupe, HR Taylor and PZ Zimmet
International Diabetes Institute, Melbourne, Australia.
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.