In the past year, our clinical studies have been oriented to (1) discriminating between the effects of primary aging vs. age- associated illness on pituitary gonadal function in men and (2) examining the interrelationships between circulating sex steroid hormone levels and various risk factors for coronary artery disease (CAD). We have measured testosterone (T), T binding, and gonadotropins in a large group of healthy men and men with benign or malignant lung disease. We found that: (a) there is an increased prevalence of both pituitary gonadotropic and testicular dysfunction in men with lung cancer and, to a lesser extent benign lung disease and (b) the effects of illness are independent of and quantitatively greater than those of aging. We also measured plasma levels of T and estradiol (E2) in 53 men prior to their development of CAD and in 136 controls who remained without CAD. We found no significant association between levels of T, E2, or the ratio T to E2 and subsequent development of CAD. We plan to initiate or continue investigations of (a) the effects of parenteral estrogen replacement on various hormonal parameters related to bone metabolism in healthy postmenopausal women of different ages, (b) the interrelationships between sex hormones and certain CAD risk factors in healthy cycling and postmenopausal women, and (c) the effects of aging on the pituitary adrenal hormone dynamics in men and women.