High luteinizing hormone and lower levels of sex hormones in younger men with distal radius fracture

This study investigates the sex steroid hormone profile in younger men with distal radius fracture (DRF) to elucidate if this could explain the low bone density and osteoporosis previously observed. In a case-control study, 73 men with DRF (mean age 38 ± 9 years; range, 20-51) was compared with 194 age-matched, population controls. Performed assays: total testosterone (TT), calculated free testosterone (cFT), luteinizing hormone (LH), follicle-stimulating hormone (FSH), sex hormone-binding globulin (SHBG), and total estradiol (E2). BMD hip and spine were measured. Fracture cases had lower cFT (298 versus 329 pmol/L; p = 0.008), but not TT, compared with controls. FSH and SHBG were not statistically different. LH was almost 30% higher (5.7 versus 4.5 IU/L; p < 0.001) and a lower E2 was observed (80.0 versus 87.1; p = 0.098). Men with DRF had a lower E2/SHBG ratio compared with controls (2.3 versus 2.9; p = 0.013). A higher proportion of the fracture group had low TT (<10.5 nmol/L; 21% versus 11%; p = 0.052), low cFT (<220 pmol/L; 18% versus 8%; p = 0.017), and low E2 (<73 pmol/L; 48% versus 35%; p = 0.044). Odds ratio (OR) for fracture when having low cFT was 2.3 (95% CI, 1.02-5.49; p = 0.044); with low E2, the OR was 1.7 (95% CI, 0.96-2.96). In this study in young men with DRF exploring sex hormone levels, we find that sex hormone profiles may be disturbed with a lower E2/SHBG ratio, lower cFT, and higher LH. Estrogen is also a strong determinant of bone mass in men; hence, low levels of E2 may be contributing to the observed lower BMD and these differences may be relevant to fracture risk. © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.