| Abstract: | Genetic and cultural determinants of total cholesterol (TC), triglyceride (TG), low- and high-density lipoprotein cholesterol (LDL-C, HDL-C), and HDL-C/TC were estimated utilizing a path model in a random sample of nearly 4,000 families examined in the Jerusalem Lipid Research Clinic. The analyses were done separately in each of the ethnic groups categorized according to the parents' country of birth (Europe, Asia, North Africa, and Israel/mixed origin) in order to identify the nature and sources of any heterogeneity among the groups. Both genetic (h2) and cultural (c2) components of inheritance were significant for all lipid variables in each of the ethnic groups. Under the most parsimonious model, estimates of h2 in the ethnic groups were .40-.55, .40-.51, .45-.50, .41-.48, and .42-.78 for TC, LDL-C, HDL-C, HDL-C/TC, and TG, respectively. The c2 ranged from 3% to 5% for TC and LDL-C and from 4% to 10% for HDL-C, HDL-C/TC, and TG. The major parameters of the path model were generally homogeneous across the origin groups. The h2 appeared to be higher in the Asian and c2 was slightly greater in the European group. The stronger sibling environmental effect in the Asia group, the somewhat lower transmission of environment in the North African group, and the lower correlation between spouse environments in the North African group were the major sources of the origin heterogeneity. Within this population, genetic factors appear to be the major determinants of lipid variations, suggesting relative homogeneity of the distribution of environmental determinants of plasma lipids. |
