Plasma lipids in twins. Environmental and genetic influences.

A study on 205 pairs of male and females twins, aged from 18 to 34 years. showed significant heritabilities for total and high density lipoprotein cholesterol and for triglycerides. Significant effects of shared environment were also found for total and HDL cholesterol, possibly to a greater extent in women than in men. Triglycerides showed greater variance in men but a model specifying different sized environmental and genetic parameters in the two sexes gave a good fit and indicated that the factors influencing plasma triglycerides are the same in men and women although the effects they produce are scaled differently.