Evaluation of sleep quality in patients with ankylosing spondylitis and efficacy of anti‐TNF‐α therapy on sleep problems: A polisomnographic study

Introduction This study was conducted to investigate the relationship between sleep quality (SQ) and disease activity (DA) in patients with ankylosing spondylitis (AS) and to evaluate the response to anti-tumor necrosis factor α (anti-TNF-α) therapy on sleep disorders. Materials and Methods A total of 34 patients who met the modified New York classification criteria for AS were included in this prospective study. Patients were divided into two groups as follows: Group I (n = 15) with high DA and receiving anti-TNF-α therapy, and Group II (n = 19) in remission. DA was assessed by the Bath AS Disease Activity Index. Pittsburgh Sleep Quality Index (PSQI) and polysomnography (PSG) were used to determine disorders and patterns of sleep, respectively, in both groups at baseline as well as at the third month of anti-TNF-α therapy in Group I. Results Baseline evaluation revealed impaired SQ in 57.9% of all patients. PSG demonstrated obstructive sleep apnea syndrome, snoring and periodic leg movements in 73.7%, 74.4% and 26.3% of patients, respectively. Prior to anti-TNF-α therapy, PSQI and snoring score were significantly higher in Group I (P = 0.0001, P = 0.012, respectively). Although there was a significant reduction in PSQI scores in Group I (P = 0.005) at the third month of anti-TNF-α therapy, no change was observed in PSG parameters (P > 0.05). Conclusion Sleep disorders increase in AS, particularly in patients with high DA. Anti-TNF-α therapy has improved SQ without any improvement in PSG. Therefore, it may be concluded that PSG parameters might be more associated with disease pathogenesis rather than DA in patients with AS.