Sleep disturbances in systemic sclerosis: evidence for the role of gastrointestinal symptoms, pain and pruritus

Objective. SSc is a rare autoimmune CTD characterized by thickening and fibrosis of skin and internal organs. There is significant mortality and no cure. Sleep disturbance has been identified as an important contributor to poor quality of life. The objective was to investigate socio-demographic and medical factors potentially associated with sleep disturbance in SSc. Methods. The sample consisted of patients from the Canadian Scleroderma Research Group's (CSRG) 15-centre, pan-Canadian Registry assessed with the 8-item Patient-Reported Outcome Measurement Information System (PROMIS) sleep disturbance scale short form, version 1.0. Pearson's correlations were used to assess bivariate association of socio-demographic and medical variables with PROMIS sleep scores. The independent association of PROMIS sleep disturbance scores and factors previously identified as associated with sleep disturbance in the general population, in SSc and other rheumatic diseases, was assessed using multiple linear regression. Results. Among 397 patients in the study (88% female, mean age 57.5 years), 25% (n = 98) had diffuse cutaneous SSc. Mean duration since onset of non-RP symptoms was 10.6 years. Number of gastrointestinal symptoms (standardized regression coefficient beta = 0.19, P = 0.001), pain severity (beta = 0.21, P < 0.001) and pruritus severity (beta = 0.13, P = 0.024) were independently associated with more severe sleep disturbance. Conclusion. Gastrointestinal symptoms, pain and pruritus were associated with sleep disturbance in SSc. Additional research is needed on sleep in SSc so that well-informed sleep interventions can be developed and tested.