The World War II veteran cohort was originally examined during the 1969-1973 period at five examination centers located in Framingham, Massachusetts; Davis, San Francisco, Los Angeles, California; and Indianapolis, Indiana. The objective of the initial examination was to estimate the heritability of cardiovascular risk factors. Results of the first examination showed significant heritability for height, weight, relative weight, systolic and diastolic blood pressure, glucose tolerance, uric acid, hematocrit, plasma triglycerides, and forced expiratory volume but not for total plasma cholesterol or any of the lipoprotein cholesterol fractions