Subjects will first be tested for possible growth hormone deficiency. This will be done by administering two intravenous medications that should stimulate growth hormone secretion and we will measure growth hormone in the blood every 30 minutes following the administration. Once we have the results on enough subjects we will split the cohort into those subjects who are growth hormone deficient and those who have normal growth hormone. The two groups will each undergo various tests all designed to assess some component of cardiovascular risk. Ultimately we will compare the results of each test to see if those who are growth hormone deficient have an increased risk for cardiovascular disease.