Anabolic steroids are derivatives of testosterone. Their exact physiologic effects on the respiratory system are unclear, but they have been studied as a possible treatment in COPD, especially for their role in potentially increasing muscle mass.
Anabolic steroids have potentially serious side effects, including effects on liver function, lipid profile, and the reproductive system. The long-term safety of anabolic steroids such as oxandrolone in SCI has not been established.
There are two studies in the literature on the effects of anabolic steroids on pulmonary function in SCI. Spungen et al. (1999) treated 10 men with motor complete C4-C5 tetraplegia with a one month course of oxandrolone, an oral anabolic steroid. Following oxandrolone, significant improvements were seen in weight gain, FVC, FEV1 and forced inspiratory vital capacity. There was a significant increase in MIP from baseline and a non-significant increase in maximal expiratory pressure (PEmax). Participants experienced a significant decrease in subjective dyspnea. There was no long-term follow-up to see if any of the improvements were permanent. Halstead et al. (2010) treated 10 male participants with motor complete tetraplegia with oxandrolone for 8 weeks and found non-significant improvements in lung function.
There is conflicting evidence (Spungen et al. 1999; Halstead et al. 2010) that the short-term use of oxandrolone improves pulmonary function in people with tetraplegia.