Serum testosterone and depressive symptoms in severe OSA patients

Obstructive sleep apnoea (OSA), also characterised by hypoxia-related sleep- fragmentation, has been studied in relation to depression and serum testosterone deficit. In middle-aged men, it has been reported the association between depressive mood and low serum testosterone level; however, no data are available about this association in OSA patients. Therefore, the aim of this study was to investigate in adult obese males, affected by severe OSA, the relationship between serum testosterone concentration and depressive symptoms, in order to identify among all measured parameters (serum testosterone morning concentration, polysomnography parameters, body mass index, Epworth Sleepiness Scale) those predictors for OSA-related depression. Forty patients diagnosed with severe OSA and forty subjects for the control-matched group were enroled in the study. The results indicated that the serum testosterone in OSA group was significantly lower than in controls. In addition, the OSA group presented a level of depression although moderate, yet significantly higher than controls. Furthermore, a statistically significant inverse correlation has been found between serum testosterone level and depressive symptoms. Among all variables, serum testosterone level was shown to be the only independent variable significantly predictor for depression in OSA patients.