The Relation Between Apnea and Depressive Symptoms in Men with Severe Obstructive Sleep Apnea: Mediational Effects of Sleep Quality.

Purpose: We determined the relationship between apnea severity and depressive symptoms in a large sample of the newly diagnosed male patients with severe obstructive sleep apnea (OSA). Methods: Data were collected from patients who received polysomnography due to suspected OSA. The questionnaires included the Beck Depression Inventory (BDI), Epworth Sleepiness Scale (ESS), and Medical Outcomes Study (MOS)-Sleep Scale, for which Sleep Problems Index-1 (SPI-1) was calculated. The apnea-hypopnea index (AHI) and respiratory distress index (RDI) were used to measure apnea severity. The mediational model, which states that OSA severity affects depression through a mediator, was tested here. Results: In total, 302 male patients with severe OSA participated. The mean patient age was 48.4 years (SD = 11.3 years). The BDI was ≥10 in 118 patients (39 %) and was significantly associated with body mass index ( r = 0.114; p = 0.048), ESS ( r = 0.164; p = 0.004), SPI-1 ( r = 0.453; p < 0.001), and RDI ( r = 0.126; p = 0.029). According to the linear regression analyses, the RDI is not independently associated with the BDI. The strongest predictor of BDI was sleep quality (SPI-1; β = 0.425; p < 0.001). The bootstrap method confirmed that the depressive effects of RDI are significantly mediated by poor sleep quality (bootstrapped 95 % CI 0.0113-0.0632). Conclusions: There is evidence of a mediational role of subjective sleep quality on the relationship between apnea severity and depressive symptoms in male patients with severe OSA. [ABSTRACT FROM AUTHOR]