Primary hypercholesterolemia, carotid atherosclerosis and insulin resistance among Chinese

We investigated the genetic contributions to carotid atherosclerosis and insulin resistance in Chinese patients with primary hypercholesterolemia. A family study of probands from the outpatient clinics in patients with high low-density-lipoprotein cholesterol levels was conducted. A total of 62 families (360 subjects) underwent carotid ultrasonography and insulin resistance measurement. The correlation coefficients of carotid intima-media thickness (IMT) were high among spouse, parent-offspring, and sibling pairs (0.39, 0.38 and 0.35, respectively). All insulin indices and IMT had significant estimates of heritability, of which fasting insulin had the highest heritability (0.410 +/- 0.104, P = 0.0001), followed by homeostasis model assessment (HOMA) (0.395 +/- 0.108, P = 0.0001). The estimated heritability of IMT was significant (0.185 +/- 0.103, P = 0.025) but not of plaque score. Bivariate genetic coefficient between IMT and HOMA was 0.569 +/- 0.292, while the environmental coefficient was 0.028 +/- 0.103. The study confirms a relationship between insulin resistance and atherosclerosis and, in particular, between insulin resistance and the thickening of the arterial wall. Moreover, it shows that genetics influence both insulin resistance and atherosclerosis, implying that the management of insulin resistance may benefit the prevention of atherosclerotic disease in familial hypercholesterolemia.