Testosterone gel significantly increase lean body mass in ageing males with relatively low bio-available testosterone and waist circumference above 94 cm: a double blinded, randomized, placebo controlled 6 months study
Louise Frederiksen1, David M Hougaard2, Kim Brixen1 & Marianne Andersen1
Background: Testosterone replacement therapy in severe hypogonadism is indicated, however, the treatment of late onset hypogonadism (LOH) is debated, especially what the diagnostic criteria should be. In LOH bio-available testosterone probably gives a more accurate index of gonadal status as a diagnostic criterion as it takes SHBG into consideration. SHBG is known to increase with ageing, however, SHBG is also negatively influenced by insulin and visceral adiposity.
Aim: To investigate the anabolic effects of testosterone in ageing men with bio-available testosterone below the cut-off limit for young males (Nielsen et al. JCEM 2006) and waist circumference above 94 cm.
Patients and methods: A double-blinded, randomized, placebo-controlled 6 months study in men aged 68 (6078) (mean and range) with bio available testosterone 4.9 (2.37.2) nmol/l and waist circumference 108 (95128) cm.
Thirty-eight participants were randomized to placebo (n=18) or testosterone gel 50 mg/day (n=20).
Testosterone levels were measured by liquid chromatography tandem mass spectrometry after ether extraction and SHBG was measured by autoDELFIA assay. Bio-available testosterone was calculated according to Vermeulen et al. (JCEM 1999). Dual X-ray absorptiometry (DXA) was used to determine total lean body mass and total fat mass.
Statistics were performed on delta values (06 months). The Students t-test was used to compare mean delta values after 24 weeks of treatment.
Results: The randomization was successful. During the 6 months study total lean body mass increased significantly (P=0.004), in the testosterone treated group compared to placebo 1.73 (−1.16.2) kg versus −0.07 (−3.41.7) kg, respectively.
Total fat mass decreased significantly (P=0.037) in the testosterone treated group compared to placebo −1.2 (−3.63.8) kg versus 0.6 (−4.01.9) kg, respectively.
Conclusion: Testosterone therapy significantly increased total lean body mass and significantly decreased total fat mass in ageing men with relatively low bio-available testosterone and waist circumference above 94 cm.