Sleep Quality and Its Predictors among Dyspnea, Fatigue and Exercise Capacity in Pulmonary Arterial Hypertension.

Background: Poor sleep quality is an overlooked symptom in patients with pulmonary arterial hypertension (PAH), however it may significantly contribute to disease burden.

Objectives: The aim of this study was to assess the sleep quality of patients with PAH and investigate its association with dyspnea, fatigue, and exercise capacity.

Methods: Forty-five patients were included. Sleep quality of the patients was assessed by the Pittsburgh Sleep Quality Index (PSQI), dyspnea levels were assessed by the UCSD-Shortness of Breath Questionnaire (UCSD-SOBQ), Baseline Dyspnea Index (BDI), Modified Medical Research Council (MMRC) dyspnea scale and Modified Borg Dyspnea scale, fatigue levels were evaluated with the Fatigue Severity Scale and Borg Rating of Perceived Exertion, and functional exercise capacity was evaluated with the 6-minute walk test (6MWT).

Results: Among the patients with PAH, 64% had poor sleep quality (PSQI > 5). PSQI score was significantly correlated with MMRC scale (r = -0.561), UCSD-SOBQ (r = 0.497), BDI (r = -0.468), and 6MWT (r = -0.412) (p < 0.05). There was no significant relationship between sleep quality and fatigue. A regression model including MMRC and 6MWT could explain 32% of variance in PSQI (p < 0.05), and MMRC score was an independent predictor for PSQI (p < 0.05). In addition, MMRC score had a greater influence on PSQI than 6MWT (β = 0.548 vs. 0.019).

Conclusions: Poor sleep quality is common in patients with PAH and is associated with poor exercise capacity and dyspnea. Patients with severe dyspnea are particularly at higher risk of poor sleep quality. Consideration of sleep-related complaints and underlying mechanisms when planning symptomatic treatments for these patients may help provide better management for PAH.