Effects of transdermal testosterone on natriuretic peptide levels in women: a randomized placebo-controlled pilot study.

OBJECTIVE To investigate whether testosterone administration alters natriuretic peptide levels in women. DESIGN Three-month, double-blind, randomized, placebo-controlled study. SETTING Clinical research center. PATIENT(S) Fifty-one women with hypoandrogenemia due to hypopituitarism. INTERVENTION(S) Transdermal testosterone (300 μg daily) or placebo patch. MAIN OUTCOME MEASURE(S) N-Terminal pro-B-type natriuretic peptide (NT-proBNP) levels. RESULT(S) NT-proBNP levels decreased in the transdermal testosterone group compared with placebo over three months. The difference between groups remained significant after controlling for baseline age, systolic blood pressure, body mass index, and homeostasis model assessment of insulin resistance. Change in NT-proBNP over 3 months was inversely associated with change in free testosterone levels. CONCLUSION(S) Testosterone administration to women results in decreased natriuretic peptide levels, suggesting that testosterone may be an inverse regulator of the natriuretic peptide system. CLINICAL TRIALS REGISTRATION NUMBER NCT00027430.