Testosterone replacement therapy (TRT) prevents further bone loss at the lumbar and femoral levels in patients with congenital hypogonadotropic hypogonadism, but it does not reliably elevate bone mineral density (BMD) out of the osteopenic/osteoporotic range, according to study results published in Andrology.
To assess the long-term effects of TRT on femoral and lumbar BMD, researchers followed 25 adult men with congenital hypogonadotropic hypogonadism who received TRT for sex steroid deficiency.
The researchers assessed each patient’s BMD, using dual-energy X-ray absorptiometry (DXA), and reported the results as T-scores. There were 6 treatment-naive patients who had DXA scans completed before initiating TRT, whereas the remaining 19 (pretreated) patients were measured for BMD after receiving TRT for a median duration of 7 years (range, 1-41 years).
The median age of those in the treatment-naive group at TRT initiation was 22.5 years (range, 18-35 years) compared with a median age of 19 years in the pretreated group (range, 12-57 years). Among the entire population, the median time between patients’ first and last DXA scan was 11 years (range, 2-28 years).
At the first DXA scan, 83% of patients had lumbar osteopenia/osteoporosis and 61% had femoral osteopenia/osteoporosis. Between the first and last DXA scans, those in the treatment-naive group saw an average lumbar T-score increase of 2.19 (P <.001) and an average femoral T-score increase of 1.47 (P <.01). Patients in the pretreated group had smaller increases, with an average lumbar T-score increase of 0.77 (P <.001) and an average femoral T-score increase of 0.19 (P =.13) between first and last DXA scans.
Despite several years of continuous TRT, 61% of patients still had lumbar osteopenia/osteoporosis and 48% had femoral osteopenia/osteoporosis. Furthermore, results revealed that BMD significantly decreased in 2 patients who interrupted TRT.
The researchers noted certain limitations to their study, including inconsistent timing between DXA scans.
“In this cohort…a deficit in bone mineral density persisted despite adequate long-term TRT,” the researchers noted. “However, most of our patients started TRT at an adult age. It is possible that initiating treatment during adolescence has the potential to prevent a BMD deficit in later life, but larger prospective studies are needed to investigate this.”
Antonio L, Caerels S, Jardi F, Delaunay E, Vanderschueren D. Testosterone replacement in congenital hypogonadotropic hypogonadism maintains bone density but has only limited osteoanabolic effects [published online March 8, 2019]. Andrology. doi:10.1111/andr.12604