Isolated hypertriglyceridemia: an insulin-resistant state with or without low HDL cholesterol

There are numerous reports on insulin resistance in subjects with hypertriglyceridemia but most of the studies involved obese or diabetic subjects. We were interested to study such events but in a population free from other confounders influencing insulin sensitivity (i.e., obesity, glucose intolerance and hypertension). From the population of a cross-sectional study we obtained 12 subjects with isolated hypertriglyceridemia and compared their insulin sensitivity with that of normolipidemic subjects in that study. Insulin sensitivity and secretory status were computed using homeostasis model assessment (HOMA) software. The insulin sensitivity of hypertriglyceridemic subjects was found to be lower than in normolipidemic subjects. For the hypertriglyceridemic subjects, insulin sensitivity (HOMA%S) was 60.07% (values adjusted for age, BMI, waist circumference, and cholesterol levels), which was substantially lower than that of normolipidemic subjects (150.03%; p<0.001). The insulin secretory status (HOMA%B) of the two groups was 248.17% and 124.63%, respectively, and significantly different (p<0.001). Relative insulin resistance, HOMA-IR, of the two groups was 4.90 and 1.54, respectively. We therefore concluded that in comparison with normolipidemic subjects, the insulin sensitivity of otherwise healthy non-obese hypertriglyceridemic subjects was lower, and that B cells had to work harder to compensate for the lowered insulin sensitivity.