Evidence for a familial form of hypertriglyceridemia as disorders coupled with insulin resistance.

To evaluate the role of insulin in familial hypertriglyceridemia, 34 relatives of the pedigrees of 3 index cases of endogenous hypertriglyceridemia and hepatic steatosis as well as 9 spouses were examined for plasma lipids and responses of blood glucose and plasma insulin during oral glucose tolerance tests. The combined disorders of hypertriglyceridemia and hyperinsulinemia plus glucose intolerance--insulin resistance--were most commonly found among the relatives, which were often accompanied by an impaired liver function. Some relatives showed hyperinsulinemia without hypertriglyceridemia. Obesity was frequent, but its incidence was similar to the controls. Thus, the observed form of familial hypertriglyceridemia was apparently coupled with insulin resistance; and hyperinsulinemia, or insulin resistance by itself, might be a basic genetical trait in this form of lipid disorder.