BALTIMORE, MARYLAND. Type 2 diabetes is a well-established cause of increased mortality and, more specifically, death from heart disease. Researchers at the Johns Hopkins University now report that even sub-clinical states of glucose intolerance confer an increased risk of premature death. Their study involved 3174 adults aged 30 to 75 years who underwent an oral glucose tolerance test between 1976 and 1980 and then were followed until they died or until 1992, whichever came first. Most (2263) participants had normal glucose tolerance, 480 had impaired glucose tolerance (a fasting glucose level less than 140 mg/dL and a plasma glucose level between 140 and 199 mg/dL two hours after ingesting 75 grams of glucose), 183 had undiagnosed diabetes (a fasting level greater than 140 mg/dL or a two-hour level greater then 200 mg/dL), and 248 had physician- diagnosed type 2 diabetes.
There were 737 deaths during the follow-up period. The all-cause mortality was highest in the diabetes group (40.9 per cent per 1000 person-years). This was followed by the undiagnosed diabetes group at 33.2 per cent, the impaired glucose tolerance group at 20.8 per cent, and the normal glucose tolerance group at 10.6 per cent. A similar risk pattern was observed for cardiovascular disease mortality by itself.
The researchers conclude that people with impaired glucose tolerance have a 40
per cent greater risk of premature death than do people with normal glucose
tolerance. Editor's Note: There is emerging evidence that lifestyle
changes and supplementation with vitamins and minerals can delay the conversion
of impaired glucose tolerance into full-blown diabetes.