Which Factors Are the Most Important for Predicting Sleep Quality in Obstructive Sleep Apnea Patients with Obesity?

Abstract

Background: Both obstructive sleep apnea (OSA) and obesity are associated with poor sleep quality. However, there have been no studies investigating sleep quality in OSA patients with obesity. The aims of this study were to (1) evaluate the sleep quality in OSA patients with obesity and (2) identify the parameters most related to sleep quality in OSA patients with obesity. Methods: Of the patients with polysomnography (PSG), OSA patients with obesity (body mass index [BMI] ≥25) were enrolled and then divided into 2 groups based on the Pittsburg Sleep Questionnaire Index (PSQI): patients with good sleep quality (PSQI ≤5, good sleepers) and those with poor sleep quality (PSQI >5, poor sleepers). In addition, we enrolled OSA patients without obesity as a disease control group. Results: Eighty-two OSA patients with obesity met the inclusion criteria (28 were good sleepers, whereas 54 were poor sleepers). We found that the BMI of the poor sleepers was significantly higher than that of the good sleepers, whereas the N-stage sleep ratio of good sleepers was higher than that of poor sleepers. Logistic ­regression analysis also showed that a high BMI and low ­N-stage sleep ratio were independently associated with poor sleep quality. In addition, BMI and N-stage sleep ratio were significantly correlated with PSQI. However, in 56 OSA patients (n = 56) without obesity, there were no differences of demographic/clinical characteristics and PSG parameters between the good (n = 18) and poor sleepers (n = 38). Discussions: About two-thirds of OSA patients with obesity show poor sleep quality. The sleep quality of these patients was more affected by the severity of obesity, but not the severity of OSA. Thus, we recommend weight loss in OSA patients with obesity to improve sleep quality as well as the severity of OSA.