SCI can be a risk factor for abnormally lower levels of testosterone (the main male hormone for sexual function and libido). In one study, 46% of men with SCI were identified as having low serum total testosterone concentrations (total testosterone <11.3 nmol/l), which is higher than seen with the age-related decline in total serum testosterone concentrations found in the general population (Baumann et al. 2014). Furthermore, the prevalence of testosterone deficiency was significantly greater in participants with motor complete (AIS A and B) injuries compared with those with motor incomplete (AIS C, D, and E) injuries, and in those taking narcotic medications for pain management (Durga 2011). Other additional factors which can lower testosterone after SCI include a concomitant brain injury, being obese, having diabetes or the metabolic syndrome, and having untreated sleep apnea (Morales et al. 2010). After SCI, reduction in serum testosterone can also lead to loss of muscle mass and gain of fat mass – a body composition that is already a problem after SCI. Body composition also plays a part in the development of pressure ulcers since muscle is better able to disperse pressure from the bony prominences than fat or skin.