Background: Ankylosing spondylitis (AS) is a chronic inflammatory disease that is associated with poor sleep quality.
Objectives: The present study aimed to investigate the relationship between disease activity and sleep quality in patients with AS and to evaluate the potential effect of anti-tumor necrosis factor (TNF) treatment on sleep quality and pattern.
Methods: Fifty-nine patients with AS were consecutively included in the study. Twenty-eight patients (47.5%) were receiving anti-TNF, and 31 (52.5%) patients were receiving only nonsteroidal anti-inflammatory drugs (NSAIDs). Demographic and treatment characteristics, spinal mobility measurements, disease activity measurements, and sleep questionnaire results of each patient were recorded. Each patient underwent a polysomnography examination for the evaluation of sleep patterns.
Results: When compared with the patients on NSAID treatment, patients receiving anti-TNF treatment had significantly greater total sleep time and sleep efficiency (P = 0.003 and P < 0.001, respectively). They had a significantly lower (better) Pittsburgh Sleep Quality Index, sleep onset latency, number of awakenings, and arousal index (P < 0.001, for all). Moreover, they had a significantly shorter superficial sleep period (stage 1) and a significantly longer rapid eye movement sleep period (P < 0.001 and P = 0.02, respectively). Higher indexes of disease activity (Bath AS Disease Activity Index, Bath AS Functional Index, and visual analog scale) were reflecting poorer sleep quality.
Conclusions: Sleep quality and pattern was markedly better in patients with AS on anti-TNF compared with the patients on NSAID treatments. Increased disease activity can impair the quality of sleep in AS. Improved sleep quality and pattern in patients on anti-TNF treatment may be related to improved disease activity.