Of the 1912 men who attended the first Gen 3 examination (2002–2005), 1893 had total testosterone measurements, 962 were 40 yr of age or younger among whom 456 men were free of cancer (self-report of physician diagnosis supported by medical records when available), CVD (occurrence of any of the following: myocardial infarction, sudden death, stroke, congestive heart failure, coronary angioplasty or coronary artery bypass surgery, claudication, or peripheral angioplasty), DM, hypertension, hypercholesterolemia, obesity, and smoking, and constituted the reference sample (Fig. 1).