OBJECTIVE - To determine the prevalence of diabetic retinopathy and ne
phropathy and to define associated risk factors in Polynesian Western
Samoans with non-insulin-dependent diabetes mellitus (NIDDM) or impair
ed glucose tolerance (IGT). RESEARCH DESIGN AND METHODS - A 1991 popul
ation-based study in Samoan adults (ages 25-74 years) included a 75-g
oral glucose tolerance lest, anthropometric measurements, and blood pr
essure recordings. Subjects with NIDDM or IGT had 45-degree stereo pho
tographs taken (n = 263) (three standard fields of the right eye), and
retinopathy was graded in comparison with Airlie House photographs. F
irst-morning urine samples (n = 304) were also collected from these su
bjects and from a subsample with normal glucose tolerance. Urinary alb
umin concentration (UAC) was measured by radio-immunoassay: microalbum
inuria was defined as UAC of 30-299 mu g/ml; and macroalbuminuria was
defined as UAC greater than or equal to 300 mu g/ml. RESULTS - The pre
valence of diabetic retinopathy was 43.2% among subjects with known di
abetes and 15.4% in those newly diagnosed. Proliferative diabetic reti
nopathy was found in 4.5% of known diabetic subjects. The prevalence o
f elevated UAC was 15.0% in subjects with IGT, 26.0% in newly diagnose
d diabetes subjects, and 23.4% in known diabetes subjects. For all dia
betic subjects (n = 162), the factors independently associated with di
abetic retinopathy (logistic regression) were duration of diabetes, fa
sting plasma glucose, and body mass index (inversely). Duration of dia
betes, serum triglyceride concentrations, and systolic blood pressure
were independently associated with elevated UAC in all diabetic subjec
ts (n = 138), and lasting plasma glucose had borderline significance.
CONCLUSIONS - Diabetic retinopathy and albuminuria are common in Polyn
esian 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 d
iabetes in Western Samoa and other developing populations with high su
sceptibility to NIDDM.