This study addressed the possible influence of apolipoprotein E (apo E) genotype on age-related changes in total cholesterol (TC), low density lipoprotein-cholesterol (LDL-C), and triglyceride (TG) levels in older males. Apo E is a component of LDL, is a ligand for the LDL receptor, and apo E genotype has been consistently associated with variation in mean levels of TC and LDL-C, and also appears to influence TG levels. Using male twins followed longitudinally between mean ages of 48 and 63 years, the change in TC, LDL-C, and TG over time for individuals with the epsilon 3 epsilon 3 and the epsilon 3 epsilon 4 genotypes was contrasted. At exam 1 mean TC and LDL-C levels were lower in the epsilon 3 epsilon 3 group than in the epsilon 3 epsilon 4 group, but at exam 3 mean TC and LDL-C levels were significantly higher in the epsilon 3 epsilon 3 group than in the epsilon 3 epsilon 4 group. The rate of change in TC and LDL-C with age differed significantly between epsilon 3 epsilon 3 and epsilon 3 epsilon 4 groups. Results for TG were not statistically significantly. These findings suggest that the apo E genotype effects on risk of coronary artery disease may be age-dependent. This study demonstrates the value of longitudinal studies in refining models for genetic risk factors for disease.
Jacques Fellay, Christian Axel Wandall Thorball, Stéphane Fournier, Roxane De La Harpe
Christopher Clark, Mehdi Gholam
Jacques Fellay, Christian Axel Wandall Thorball, Zhi Ming Xu, Flavia Aurelia Shoko Hodel, Roxane De La Harpe