To determine the 10 -yr incidence of impaired glucose tolerance and NIDDM in families with a clustering of endogenous hypertriglyceridemia.
The prospective population study, where the oral glucose tolerance test and the measurement of serum lipids and lipoproteins were performed at the baseline examination and after the 10-yr followup, was conducted on 56 subjects (17–60 yr of age at the baseline). The subjects were from six pedigrees with a clustering of endogenous hypertriglyceridemia, and 47 of these subjects attended the follow-up 10 yr later.
In the study families, the prevalence of glucose intolerance and NIDDM increased from 15 to 49% (P < 0.001) and from 2 to 21% (P < 0.001), respectively, over the 10-yr period. When grouped according to the baseline serum triglyceride tertiles, 76% (P < 0.01) of the family members with highest serum triglycerides were glucose intolerant (29% impaired glucose tolerance, 47% NIDDM) at follow-up compared with 20% of those with lowest serum triglycerides. In discriminant analysis, including age, body mass index, treatment with thiazides and β-blocking agents, and 2-h serum insulin concentration, the baseline serum triglycerides still remained as an independent predictor of development of impaired glucose tolerance and NIDDM.
Families with a clustering of hypertriglyceridemia are at increased risk of NIDDM, and in these families elevation of serum triglycerides serves as a risk marker of glucose intolerance and NIDDM.