Short-term effects of intramuscular and transdermal testosterone on bone turnover, prostate symptoms, cholesterol, and hematocrit in men over age 70 with low testosterone levels.

The objective of the study was to determine whether short-term testosterone administration to older men with low bioavailable testosterone would have any immediate adverse effects, especially on the symptoms of benign prostat e hyperplasia, preliminary to embarking on a long-term study of testosteron e treatment. Transdermal and intramuscular testosterone were compared to de termine whether there were any rapid changes in markers of bone formation o r resorption with either testosterone administration. We undertook a nonran domized trial of 9 weeks intervention with either intramuscular testosteron e, transdermal testosterone or neither followed by a 9-week observation per iod. Twenty-seven men over age 70 years with no medical conditions known to affect bone turnover and total testosterone levels below 350 ng/dl (normal range 3501230 ng/dl) or bioavailable testosterone levels below 128 ng/dl ( normal range 128-430 ng/dl) received either testosterone via transdermal pa tch (TP; two 2.5 mg patches/d), intramuscular testosterone enanthate (IM; 2 00 mg every 3 weeks) or no testosterone for 9 weeks of treatment followed b y a 9 week observation period. Nine men were enrolled in each group. The me an age of the men was 74+/-3 years (range 70-83 years). While all men recei ving testosterone treatment increased levels above their own baseline, only 6 of 9 men receiving transdermal testosterone achieved bioavailable testos terone levels in the normal range for young men. Neither treatment group de monstrated changes in estradiol levels. No side effects were reported using the intramuscular testosterone while 5/9 men using transdermal testosteron e developed a rash. There were no significant changes in markers of bone re sorption or formation in either testosterone treatment group. There were no ill effects on prostate size, symptoms or prostate specific antigen level. PSA levels of 1.5 +/- 0.7 ng/dl and 1.6 +/- 0.7 ng/dl in the TP and IM gro ups, respectively. were 2.0 +/- 1.0 ng/dl and 1.8 +/- 0.9 ng/dl following t reatment. Cholesterol profiles were also not affected by either transdermal or intramuscular testosterone. Similarly hemoglobin and hematocrit remaine d unchanged in men receiving either testosterone preparation.