Nocturnal pain and pain sensitivity–related symptoms are associated with poor sleep quality in patients with hip osteoarthritis

Objective: To investigate the associations between nocturnal pain, symptoms related to altered pain sensitivity, and sleep quality in patients with hip osteoarthritis (OA). Design: This cross-sectional study enrolled 129 patients with unilateral hip OA scheduled for total hip arthroplasty. After applying exclusion criteria, 100 patients were included. Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI), and poor sleep quality was defined as PSQI >5. Symptoms related to altered pain sensitivity were evaluated using the Central Sensitization Inventory (CSI). Nocturnal pain frequency was assessed using the PSQI component. Group comparisons, logistic regression, and correlation analyses were performed. Results: Poor sleep quality was identified in 56 patients (56%). The poor-sleep group showed higher CSI scores (mean difference, 7.0; 95% CI, 4.0 to 11.0) and higher nocturnal pain frequency (mean difference, 1.0; 95% CI, 0.0 to 2.0) than the control group. In multivariable logistic regression analysis, nocturnal pain frequency (odds ratio OR, 2.069; 95% CI, 1.217-3.525) and CSI score (OR, 1.084; 95% CI, 1.004-1.170) were independently associated with poor sleep quality. A moderate positive correlation was observed between nocturnal pain frequency and CSI score (ρ = 0.343). Conclusions: Nocturnal pain frequency and CSI scores were independently associated with sleep quality and were also interrelated in patients with hip OA. These findings suggest that evaluation of poor sleep quality should focus on patient-reported symptoms, including nocturnal pain and symptoms related to altered pain sensitivity.