Clinical trial NCT00112151
Conditions: Healthy
Keywords: andropause hypogonadism AndroGel exercise PRT Testosterone T supplementation
Sponsor: University of Colorado, Denver
Start date: 2005-01-01; Completion date: 2010-11-01
Enrollment: 167 participants; Allocation: RANDOMIZED; Intervention model: FACTORIAL

Brief summary:
The purpose of this study is to evaluate the effects of testosterone supplementation (AndroGel) on body composition, strength, endurance, cognition, and function in older men.

Detailed description:
Studies suggest that testosterone (T) replacement in healthy elderly men has beneficial effects on body composition, muscle, bone, memory, and behavior, but the risks of chronic treatment, especially on the prostate, heart, and sleep quality, are not entirely clear. Therefore, it is most desirable to supplement into the lowest "effective" range in elderly men. However, the effects of lower than usual replacement T doses have not been well studied. Furthermore, the possible important interaction of exercise to enhance the positive effects of T supplementation, yet mitigate the possible side effects, has not been studied in older men.

This one-year study will enroll 150 men with low-normal to slightly below normal serum total T levels. Participants will be randomized into one of 6 treatment groups to receive T supplementation (AndroGel) of 25mg/day, 50 mg/day or a placebo crossed with progressive resistance training (PRT) exercise 3 times a week versus none. At the end of the study, participants in the exercise-control group will be offered PRT.

Please see link below for updated version of full protocol.

Arms: arm 1: Low Dose Testosterone Group applies one 2.5 gm active packet and one placebo packet, titrated to a target blood range of 400-550 pg/ml)

1 year standard Progressive Resistance Training(PRT) program arm 2: Low Dose Testosterone Group applies one 2.5 gm active packet and one placebo packet, titrated to a target blood range of 400-550 pg/ml)

No exercise program arm 3: High Dose Testosterone Group applies two 2.5 gm active packets, titrated to a target blood range of 600-1000 pg/ml)

1 year standard Progressive Resistance Training(PRT) program arm 4: High Dose Testosterone Group applies two 2.5 gm active packets, titrated to a target blood range of 600-1000 pg/ml)

No exercise program arm 5: Placebo Group applies two 2.5 gm placebo packets

1 year standard Progressive Resistance Training(PRT) program arm 6: Placebo group applies two 2.5 gm placebo packets

No exercise program
Interventions: intervention 1: LowT intervention 2: Resistance Training intervention 3: Placebo intervention 4: HighT
Intervention descriptions: intervention 1: Low Dose Testosterone Group applies one 2.5 gm active packet and one placebo packet, titrated to a target blood range of 400-550 pg/ml)during the first 12 weeks. Total exposure duration is 52 weeks. intervention 2: Weight training 45-60 minutes 3 times per week intervention 3: 2.5 gm gel packets applied once daily. Sham adjustments made during the first 12 weeks. Duration is 52 weeks. intervention 4: High Dose Testosterone Group applies two 2.5 gm active packets, titrated to a target blood range of 600-1000 pg/ml)during the first 12 weeks. Total exposure duration is 52 weeks.

Protocol documents: