Intramuscular TRT is more effective than transdermal formulations at increasing LBM and improving muscle strength  in middle-aged and older men , particularly in the lower extremities
BACKGROUND Inconsistent fat-free mass ( FFM ) and muscle strength responses have been reported in r and omized clinical trials ( RCTs ) administering  testosterone replacement therapy ( TRT ) to middle-aged and older men .
Our objective was to conduct a meta- analysis to determine whether TRT improves FFM and muscle strength in middle-aged and older men and whether the muscular responses vary by TRT administration route .
Independent and combined effects of testosterone and growth hormone on extracellular water in hypopituitary men.
CONTEXT Symptoms of fluid retention in GH-deficient patients during GH replacement  are greater in men than in women , suggesting that testosterone may augment or estradiol may attenuate the antinatriuretic actions of GH . The mechanisms underlying the sodium-retaining effects of GH are poorly understood . AIM The aim of this study was to investigate the effects of GH and testosterone , alone and in combination , on extracellular water ( ECW ) and the hormonal mechanisms involved . DESIGN Two separate , open-label , r and omized , two-period , crossover studies were performed ; the first compared the effects of GH alone with those of GH and testosterone , and the second compared the effects of testosterone alone with those of GH and testosterone . PARTICIPANTS Twelve hypopituitary men with GH deficiency and hypogonadism were studied . INTERVENTION During the weeks of intervention , GH ( 0.5 mg/d ) and testosterone enanthate ( 250 mg ) were administered by i m injection . OUTCOME MEASURES The outcome measures were ECW , IGF-I , plasma renin activity ( PRA ) , aldosterone ( Aldo ) , and atrial natriuretic peptide ( ANP ) . RESULTS GH treatment significantly increased ( P < 0.05 ) both IGF-I and ECW , and these changes were enhanced by cotreatment with testosterone ( P = 0.07 for both ) . PRA , Aldo , and ANP levels did not change . Testosterone treatment alone did not change the IGF-I concentration , whereas cotreatment with GH induced a marked increase . Testosterone alone increased ( P < 0.05 ) ECW , and the effect was augmented ( P < 0.01 ) by cotreatment with GH . Although PRA and ANP did not change , plasma Aldo decreased after single and combined treatments . CONCLUSION GH and testosterone exerted independent and additive effects on ECW . The mechanisms of fluid retention for both hormones are likely to be exerted on the renal tubules . This is the first direct evidence that testosterone increases ECW
Intramuscular TRT is more effective than transdermal formulations at increasing LBM and improving muscle strength  in middle-aged and older men , particularly in the lower extremities
BACKGROUND Inconsistent fat-free mass ( FFM ) and muscle strength responses have been reported in r and omized clinical trials ( RCTs ) administering  testosterone replacement therapy ( TRT ) to middle-aged and older men .
Our objective was to conduct a meta- analysis to determine whether TRT improves FFM and muscle strength in middle-aged and older men and whether the muscular responses vary by TRT administration route .