title: Vascular reactivity in hypogonadal men is reduced by androgen substitution.
abstract: The effect of testosterone (T) substitution therapy on blood vessel functions in relation to cardiovascular disease has not been fully elucidated. In 36 newly diagnosed nonsmoking hypogonadal men (37.5 +/- 12.7 yr) endothelium-dependent flow-mediated vasodilatation (FMD; decreased in atherosclerosis) of the brachial artery was assessed before treatment and after 3 months of T substitution therapy (250 mg testosterone enanthate im every 2 wk in 19 men, human chorionic gonadotropin sc twice per week in 17 men). Twenty nonsmoking controls matched for age, low-density lipoprotein cholesterol (LDL-C), body height, and baseline diameter of the artery were selected for repeated measurements from a larger eugonadal control group (n = 113). In hypogonadal men, basal FMD (17.9 +/- 4.5%) was significantly higher than in the large (11.9 +/- 6.4%) and matched control (11.8 +/- 7.1%, both P < 0.001) groups. Grouped multiple linear regression analysis revealed a significant negative association of T levels with FMD within the hypogonadal range, but no significant association was seen within the eugonadal range. During substitution therapy, T levels increased from 5.8 +/- 2.3 to 17.2 +/- 5.1 nmol/liter and FMD decreased significantly to 8.6 +/- 3.1% (P < 0.001, analysis for covariance for repeated measurements including matched controls). LDL-C and advanced age contributed significantly to decrease FMD (P = 0.01, P = 0.04, respectively). Because T substitution adversely affects this important predictor of atherosclerosis, other contributing factors (such as smoking, high blood glucose, and LDL-C) should be eliminated or strictly controlled during treatment of hypogonadal men.
authors.affiliation: Institute of Reproductive Medicine, University of Münster, Domagkstrasse 11, D-48129 Münster, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Zitzmann
authors.forename: Maik
authors.initials: M
authors.lastname: Brune
authors.forename: Eberhard
authors.initials: E
authors.lastname: Nieschlag
mesh_terms: D000328:Adult; D000368:Aged; D001794:Blood Pressure; D015992:Body Mass Index; D001916:Brachial Artery / Q000000981:diagnostic imaging; D002318:Cardiovascular Diseases / Q000139:chemically induced; D002784:Cholesterol / Q000097:blood; D006063:Chorionic Gonadotropin / Q000008:administration & dosage / Q000627:therapeutic use; D004730:Endothelium, Vascular / Q000503:physiopathology*; D004958:Estradiol / Q000097:blood; D020249:Hormone Replacement Therapy / Q000009:adverse effects; D019382:Human Growth Hormone / Q000097:blood; D006801:Humans; D007006:Hypogonadism / Q000188:drug therapy* / Q000503:physiopathology*; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D013739:Testosterone / Q000008:administration & dosage / Q000009:adverse effects* / Q000031:analogs & derivatives* / Q000097:blood / Q000627:therapeutic use; D014280:Triglycerides / Q000097:blood; D014463:Ultrasonography; D014664:Vasodilation / Q000187:drug effects*
chemical_list: D006063:Chorionic Gonadotropin; D014280:Triglycerides; D019382:Human Growth Hormone; D013739:Testosterone; D004958:Estradiol; D007334:Insulin-Like Growth Factor I; C004648:testosterone enanthate; D002784:Cholesterol