Objective: To determine the 10-yr incidence of impaired glucose tolerance and NIDDM in families with a clustering of endogenous hypertriglyceridemia.
Research design and methods: 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 follow-up, 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.
Results: 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 beta-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.
Conclusions: 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.