Introduction: With the recent increased recognition and treatment of hypogonadism in men, a caution has been given that testosterone replacement therapy (TRT) may cause or aggravate obstructive sleep apnea syndrome (OSA).
Aim: To evaluate the scientific data behind the cautionary statements about TRT and OSA.
Main outcome measures: Methodology and criteria for such studies and evaluation of documents and results based on methodology, duration, and outcome of treatment.
Methods: A review of the literature on the subject of TRT and OSA was performed. The possible mechanisms of action of TRT, on breathing and respiration during sleep were explored.
Result: Historically, the first such caution came in 1978. Since then, a few similar incidence reports have been cited. The total number of patients in such reports was very small, very disproportional to the millions of patients treated with TRT. Also, there was a lack of consistent findings connecting TRT to OSA. In addition, different results may occur with physiologic replacement vs. supraphysiologic doses in regard to breathing and OSA. The studies showing the effect of TRT on OSA and breathing were all case studies with small numbers of subjects and showed little effect of TRT on OSA in the majority of case reports. Only one study using supraphysiologic doses was a double-blind, placebo-controlled study, which showed a development of OSA in healthy pooled subjects. The other reports were case studies with limited numbers of subjects, suggesting an inconsistent effect of supraphysiologic TRT on OSA and breathing.
Conclusion: Cautionary statements about TRT in OSA appear frequently in the TRT literature and guidelines, despite lack of convincing evidence that TRT causes and/or aggravates OSA. Also, there is a lack of consistency in the findings connecting TRT to OSA. It is evident that the link between TRT and OSA is weak, based on methodological issues in many of the studies, and most studies involved small numbers of men. Further studies in this area are needed.