Sleep Disorders in Patients with Systemic Sclerosis: A Systematic Review and Meta-Analysis.

Background : Systemic sclerosis is a rare autoimmune disease associated with substantial morbidity and reduced quality of life. Sleep disturbance has been reported with variable frequency in patients with systemic sclerosis, though its prevalence remains incompletely characterised. Objective : This systematic review and meta-analysis aimed to estimate the pooled prevalence of sleep disorders in patients with systemic sclerosis. Methods : Six databases were searched up to 15 February 2026 without language restriction. Studies reporting sleep outcomes in adults with systemic sclerosis were eligible. Prevalence estimates were pooled using a logit transformation with a random-effects model and Hartung-Knapp correction. Heterogeneity was assessed using the I² statistic. Publication bias was evaluated with Egger's test and the trim-and-fill method. This review was registered in PROSPERO (CRD420251152354). Results : Twenty-three studies totalling 1,487 patients were included across all analyses. Eleven studies (820 patients) contributed to the primary meta-analysis of poor sleep quality assessed by the Pittsburgh Sleep Quality Index. The pooled prevalence of poor sleep quality was 76.49% (95% CI 66.62 to 84.13%), with moderate to substantial heterogeneity (I² = 70.1%) and a 95% prediction interval of 49.66% to 91.47%, indicating that the true prevalence may range from approximately half to nearly all patients across different SSc populations. Five studies (346 patients) contributed to the obstructive sleep apnea meta-analysis, yielding a pooled prevalence of 40.30% (95% CI 25.56 to 57.04%, I² = 71.8%) with a 95% prediction interval of 13.95% to 73.75%. Five additional studies were included in a qualitative synthesis only, and three randomised controlled trials addressed sleep interventions. Egger's test identified possible funnel plot asymmetry. After trim-and-fill adjustment, four studies were imputed and the corrected estimate was 69.62% (95% CI 57.33 to 79.63%), somewhat lower than the primary estimate, suggesting that the primary estimate may be modestly influenced by publication bias. The certainty of evidence was rated as low according to GRADE. Conclusion : Available evidence suggests that sleep disorders may affect approximately three quarters of patients with systemic sclerosis when assessed by the PSQI, and obstructive sleep apnea may affect more than one third when evaluated by objective tools. These estimates carry low GRADE certainty and wide prediction intervals, and should not be interpreted as definitive prevalence figures. Larger prospective studies and well-powered randomised trials are needed to establish more precise estimates and to evaluate targeted sleep interventions in this population.