Could HRT help men with low testosterone levels?
Q - A 55-year-old man has a low testosterone level, found during screening after wrist and hip fractures. Can HRT help?
A - Testosterone levels in men have to be interpreted with caution. There is an age-related decline in serum testosterone concentrations, which normal ranges do not reflect. The measurement was likely to be 'total testosterone', most of which is found in the sex hormone binding globulin (SHBG). SHBG is inversely related to weight, so obese men will have low testosterone but are unlikely to be hypogonadal. Many use serum LH and FSH as arbitrators in this situation.
Significant hypogonadism will reflect itself with raised gonadotrophin concentrations. A measurement of prolactin would exclude a common cause of deficiency.
A few studies have shown that treating hypogonadal men with testosterone has a positive effect on bone. There is no good data on reduced fracture risk or as secondary prevention. The risks of testosterone therapy include exacerbating prostatic symptoms, increasing risk of prostate cancer and polycythaemia. Hypogonadal men receiving testosterone should have regular prostate surveillance including PSA and a full blood count noting the haematocrit.
Given the limited data, a bisphosphonate is probably a better treatment in this case, unless clear-cut hypogonadism reveals itself. If he is hypogonadal he might obtain wider benefits from testosterone.
Dr Gerard Conway is consultant endocrinologist at UCL hospitals