Intramuscular testosterone moderately increased lumbar bone density in men ; the results on femoral neck bone density are inconclusive .
Without bone fracture data , the available trials offer weak and indirect inferences about the clinical efficacy of testosterone on osteoporosis prevention and treatment in men
CONTEXT And rogen-deficient men are at increased risk of osteoporosis .
The extent to which testosterone can prevent and treat osteoporosis in men remains unclear .
Effects of transdermal testosterone on bone and muscle in older men with low bioavailable testosterone levels.
BACKGROUND A large proportion of men over 65 years of age have bioavailable testosterone levels below the reference range of young adult men . The impact of this on musculoskeletal health and the potential for improvement in function in this group with testosterone supplementation require investigation . METHODS Sixty-seven men ( mean age 76 + /- 4 years , range 65 - -87 ) with bioavailable testosterone levels below 4.44 nmol/l ( lower limit for adult normal range ) were r and omized to receive transdermal testosterone  ( two 2.5-mg patches per day ) or placebo patches for 1 year . All men received 500 mg supplemental calcium and 400 IU vitamin D. Outcome measures included sex hormones ( testosterone , bioavailable testosterone , sex-hormone binding globulin [ SHBG ] , estradiol , and estrone ) , bone mineral density ( BMD ; femoral neck , Ward 's triangle , trochanter , lumbar spine , and total body ) , bone turnover markers , lower extremity muscle strength , percent body fat , lean body mass , hemoglobin , hematocrit , prostate symptoms , and prostate specific antigen ( PSA ) levels . RESULTS Twenty-three men ( 34 % ) withdrew from the study ; 44 men completed the trial . In these men , bioavailable testosterone levels increased from 3.2 + /- 1.2 nmol/l ( SD ) to 5.6 + /- 3.5 nmol/l ( p < .002 ) at 12 months in the testosterone group , whereas no change occurred in the control group . Although there was no change in estradiol levels in either group , estrone levels increased in the testosterone group ( 103 + /- 26 pmol/l to 117 + /- 33 pmol/l ; p < .017 ) . The testosterone group had a 0.3 % gain in femoral neck BMD , whereas the control group lost 1.6 % over 12 months ( p = .015 ) . No significant changes were seen in markers of bone turnover in either group . Improvements in muscle strength were seen in both groups at 12 months compared with baseline scores . Strength increased 38 % ( p = .017 ) in the testosterone group and 27 % in the control group ( p = .06 ) , with no statistical difference between the groups . In the testosterone group , body fat decreased from 26.3 + /- 5.8 % to 24.6 + /- 6.5 % ( p = .001 ) , and lean body mass increased from 56.2 + /- 5.3 kg to 57.2 + /- 5.1 kg ( p = .001 ) , whereas body mass did not change . Men receiving testosterone had an increase in PSA from 2.0 + /- 1.4 microg/l to 2.6 + /- 1.8 microg/l ( p = .04 ) , whereas men receiving placebo had an increase in PSA from 1.9 + /- 1.0 microg/l to 2.2 + /- 1.5 microg/l ( p = .09 ) . No significant differences between groups were seen in hemoglobin , hematocrit , symptoms or signs of benign prostate hyperplasia , or PSA levels . CONCLUSIONS Transdermal testosterone ( 5 mg/d ) prevented bone loss at the femoral neck , decreased body fat , and increased lean body mass in a group of healthy men over age 65 with low bioavailable testosterone levels . In addition , both testosterone and placebo groups demonstrated gains in lower extremity muscle strength , possibly due to the beneficial effects of vitamin D. Testosterone did result in a modest increase in PSA levels but result ed in no change in signs or symptoms of prostate hyperplasia
Intramuscular testosterone moderately increased lumbar bone density in men ; the results on femoral neck bone density are inconclusive .
Without bone fracture data , the available trials offer weak and indirect inferences about the clinical efficacy of testosterone on osteoporosis prevention and treatment in men
CONTEXT And rogen-deficient men are at increased risk of osteoporosis .
The extent to which testosterone can prevent and treat osteoporosis in men remains unclear .