From the article:
Thirteen older men between 60 – 85 years have thusfar participated in the study. Testosterone levels ranged between 200-500 nanograms (ng) of testosterone per deciliter of blood (dL) at the time of enrollment. (Normal limits are considered 250-800.) Each was enrolled in one of three double-blinded groups: (1) those receiving continuous weekly intramuscular injections of testosterone (100 mg testosterone-enanthate) for the entire five month period (TE; n=4); (2) those receiving weekly testosterone every other month (one month of weekly testosterone/one month of weekly placebo; MO; n=4); or (3) those receiving a weekly placebo for the entire five month period (PL; n=5).
The participants visited the clinic weekly for either scheduled treatment injections or placebos. Volunteers received a baseline whole-body Dual Energy X-Ray Absorptiometry (DEXA) scan at the beginning and end of the study. Dietary records were obtained and analyzed at month zero, month three and month five. Fasting blood samples were collected at regular intervals throughout the study to examine serum markers of bone metabolism.
Preliminary Study Results
– testosterone administration appears to reduce bone turnover, perhaps closing the gap between resorption and formation
– thus far, the impact on bone mineral density are unclear but may become more apparent as the study progresses.
– the effects of testosterone on long-term bone metabolism are unclear, but are expected to have at least a protective effect on existing bone mass over time by preventing unwanted increases in bone turnover that are frequently associated with osteoporosis. Osteoporosis is often associated with high bone turnover (increases in bone resorption as well as in bone formation) which results in decreased BMD.