Men and women with chronic insomnia disorder and OSAS: Different responses to CPAP

To evaluate the response to CPAP in patients with chronic insomnia disorder (CID) with OSAS in an unselected patient population including all OSAS severity groups. As a secondary objective, we also wanted to evaluate the differences between patients that improve insomnia symptoms with CPAP and patients that do not improve, specifically evaluating possible gender differences.

Retrospective study of patients with a diagnosis of OSAS treated with CPAP and CID at the first clinical visit, selected from a database of an outpatient sleep clinic of University Hospital.

From a database of total of 827 patient, 90 patients were identified with OSAS and CID (53.3% women). Middle / moderate OSAS was diagnosed in 68.9% and severe OSA in 31.1%. Most patients (61.1%) improved insomnia symptoms after CPAP therapy. In the responders group, 58.2% had initial insomnia, 63.6% middle insomnia and 12.7% late insomnia. Responders to CPAP were more frequently women (women 61.8%, men 38.2%, p = 0.035) and there was no other difference between responders and non-responders. On subgroup analysis, this difference was significant only in severe OSAS (women 88.9%, men 31.6%, p = 0.013).

In most patients with CID and OSA, there is a consistent reduction of insomnia symptoms with the CPAP use. This factor emphasizes the importance of performing PSG in CID. Insomnia in men with severe OSAS responds less frequently to CPAP suggesting that in these cases the insomnia phenotype is less dependent on the respiratory symptoms.