Effects of normalization of plasma testosterone levels in hypogonadal men on plasma levels and urinary excretion of asymmetric dimethylarginine (ADMA)

• Published in: Hormone and metabolic research Vol. 40; no. 1; p. 56
• Main Authors: Leifke, E, Kinzel, M, Tsikas, D, Gooren, L, Frölich, J C, Brabant, G
• Format: Journal Article
• Language: English
• Published: Germany 01-01-2008
• Subjects: Adult; Aged; Arginine - analogs & derivatives; Arginine - blood; Arginine - urine; Body Mass Index; Humans; Hypogonadism - blood; Hypogonadism - urine; Male; Middle Aged; Nitrates - blood; Nitrites - blood; Testosterone - blood
• ISSN: 0018-5043
• DOI: 10.1055/s-2007-1004529

Elevated plasma levels of asymmetric dimethylarginine (ADMA) inhibit nitric oxide formation and exert a proatherogenic action. Low testosterone (T) levels are associated with increased cardiovascular risks. This study analyzed the effects of normalization of plasma T levels on plasma levels and urinary excretion of ADMA in hypgonadal men (n=10) receiving transdermal T administration. Plasma T levels, starting from clearly hypogonadal T plasma concentrations with a mean level of 4.0+/-2.72 nmol/l at baseline, rose to >10 nmol/l after 2 weeks, with plasma T levels within the normal range of men (mean level of 22.5+/-11.3 nmol/l) over the last 16 weeks of the 24 weeks of T administration. Normalization of plasma T led to a small but significant fall of plasma ADMA (519+/-55 vs. 472+/-59 nmol/l, p=0.031). The outcome of this study may be viewed as a favorable effect of normalization of plasma testosterone on plasma ADMA since even small elevations of plasma ADMA significantly increase cardiovascular risk. While this effect of normalization of plasma T may impress as favorable, most available studies on effects of T administration to hypogonadal men have not shown beneficial effects on functions of the vascular wall.