Abstract
From 1960 to 1975, a diabetes detection drive was conducted in a typical Japanese rural district, Kasai City, which has a low-mobility population.
At the first screening, urine was examined for sugar postprandially by Tes Tape. Positive subjects then underwent a second test, this consisted of a 50 g oral glucose tolerance test (GTT) carried out in the early morning.
In 1960, the GTT patterns were found to be 35.3% diabetic, 18.6% borderline, 22.1% renal glycosuric, and 24.0% normal; in 1970, 35.1%, 53.8%, 5.4% and 8.4%; and in 1975, 56.5%, 40.9%, 2.1% and 2.0%, respectively. As time progressed, the proportion of renal glycosurics thus tended to decrease, whereas diabetes mellitus increased.
From these results, we selected borderline and renal glycosuric cases as suspected diabetics and traced them for 15 yr to determine their prognosis. Twenty-six suspected diabetics were individually traced every 5 yr for 15 yr. Four cases (15.4%) shifted to a diabetic pattern in 1965 and in 1970; the number rose finally to 15 cases (57.7%) in 1975. Thus over half of these suspected diabetics had shown a diabetic pattern after 10 yr.
Obesity and aging accompanied a reduced glucose tolerance in these cases but family histories did not. The cases shifting to a diabetic pattern from suspected diabetes during the 15 yr followup showed a tendency for their blood glucose level at 2 hr after ingestion of the glucose load in 1960 to be higher than the fasting blood glucose. Their mean IRI responses (IRI/BS) tended to be low but this result was not statistically significant. Concerning diabetic complications, they showed no signs. The expected survival rate in the suspected diabetics was not significantly different from the relative survival rate. The principal cause of death was cerebrovascular accident, as in diabetics.
