This study was ancillary to the Systolic Hypertension in the Elderly Program (SHEP) clinical trial. Participants of the SHEP at the University of Pittsburgh were used for the hypertensive population. Patients screened for SHEP but rejected because of normal blood pressure were used for the controls. Carotid disease was assessed by duplex scanning, a noninvasive technique that combined real time B-mode ultrasound with Doppler ultrasound, producing a system capable of both vessel imaging and analysis of blood flow characteristics. Other evaluations included ankle systolic blood pressure measurements to detect lower extremity arterial disease, complete history and physical examination, electrocardiogram, blood lipoprotein levels, fasting insulin and glucose levels, hemoglobin, and hematocrit. Thus, the effects of various risk factors on the development of carotid atherosclerosis were evaluated as well as the relationship between carotid atherosclerosis and peripheral arterial disease of the lower extremities. The first six months of the study consisted of preparation and reproducibility testing of duplex scan measurements. During the following three years, duplex scans and other evaluations were completed on all 400 participants. During the final half of the fourth year, the first 100 duplex scans of hypertensive participants were repeated to determine whether it was possible to measure disease progression using this methodology. The study began in FY 1988 under R29HL39871 and continued in FY 1993 under R01HL50439.