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 .
Testosterone replacement in older hypogonadal men: a 12-month randomized controlled trial.
A decline in testicular function is recognized as a common occurrence in older men . However data are sparse regarding the effects of hypogonadism on age-associated physical and cognitive declines . This study was undertaken to examine the year-long effects of testosterone administration in this patient population . Fifteen hypogonadal men ( mean age 68 + /- 6 yr ) were r and omly assigned to receive a placebo  , and 17 hypogonadal men ( mean age 65 + /- 7 yr ) were r and omly assigned to receive testosterone .  Hypogonadism was defined as a bioavailable testosterone < 60 ng/dL. The men received injections of placebo or 200 mg testosterone cypionate biweekly for 12 months . The main outcomes measured included grip strength , hemoglobin , prostate-specific antigen , leptin , and memory .  Testosterone improved bilateral grip strength ( P < 0.05 by ANOVA ) and increased hemoglobin ( P < 0.001 by ANOVA ) . The men assigned to testosterone had greater decreases in leptin than those assigned to the control group ( mean + /- SEM : -2.0 + /- 0.9 ng/dL vs. 0.8 + /- 0.7 ng/dL ; P < 0.02 ) . There were no significant changes in prostate-specific antigen or memory .  Three subjects receiving placebo and seven subjects receiving  testosterone  withdrew from the study . Three of those seven withdrew because of an abnormal elevation in hematocrit .  Testosterone supplementation improved strength , increased hemoglobin , and lowered leptin levels in older hypogonadal men .  Testosterone may have a role in the treatment of frailty in males with hypogonadism ; however , older men receiving testosterone must be carefully monitored because of its potential risks
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 .