TESTOSTERONE DECREASES LIPOPROTEIN(A) IN MEN

Lipoprotein(a) [Lp(a)] has recently emerged as Lan important risk fact or for atherosclerotic cardiovascular disease.(1) Lp(a) levels are lar gely under genetic control and have proved remarkably resistant to the rapeutic manipulations.(1) Of the commonly used lipid-lowering medicat ions, only high-dose niacin appears to reduce Lp(a) levels.(2) Others have demonstrated that estrogen(3) and the anabolic-androgenic steroid stanozolol(4) reduce Lp(a) concentrations in postmenopausal women, bu t to our knowledge, the effect of androgenic hormone administration on Lp(a) in men has not been examined. Testosterone is normally aromatiz ed to estradiol, and peripheral aromatization of testosterone is the m ajor source of circulating estrogen in men.(5) We recently examined th e effect of testosterone aromatization on serum lipid and lipoprotein levels in men by administering testosterone alone or in combination wi th the aromatase inhibitor testolactone.(6) Recent reports that estrog en decreases Lp(a)(3) prompted us to examine Lp(a) levels from our stu dy to determine the effects of testosterone and its aromatization to e stradiol on Lp(a) levels.