Correlates of low testosterone in men with chronic spinal cord injury

Although high rates of serum testosterone deficiency have been reported in men with spinal cord injury (SCI), its determinants and attributes are not yet established. The aim of this study was to recognize, among putative determinants and attributes of androgen deficiency, those significantly associated to low testosterone after adjustment for confounders recognizable in men with chronic SCI. A biochemical androgen deficiency (total testosterone <300 ng/dL) was exhibited by 18 of 51 patients (35.3%). Significant correlates of testosterone levels were as follows: weekly leisure time physical activity (LTPA) explored by the LTPA Questionnaire for people with SCI, body mass index (BMI), homeostatic model assessment of insulin resistance (HOMA-IR), triglycerides and sexual symptoms, explored by the aging males' symptom (AMS) questionnaire. At the multiple linear regression analysis, among putative determinants of low testosterone, only weekly LTPA and BMI exhibited a significant association with testosterone levels, explaining 54.2 and 9.0% of testosterone variability respectively. At the linear regression models, among various putative attributes of androgen deficiency, only lower sexual desire and, at a lesser extent, higher HOMA-IR, exhibited significant associations with lower testosterone levels, after adjustment for BMI, age, comorbidities and weekly LTPA. In conclusion, poor LTPA, high BMI and low sexual desire are independent predictors of low testosterone in men with chronic SCI. This is relevant to clinical practice, as all these features are routinely assessed in rehabilitation settings for SCI. As poor LTPA and high BMI are modifiable life-style related risk factors, prospective studies could clarify whether life-style modification could increase the level of testosterone and improve the low sexual desire, relevant clinical attribute of low testosterone in men with SCI.