Fibromyalgia prevalence and associated factors in primary Sjogren's syndrome patients in a large cohort from the Spanish Society of Rheumatology registry (SJOGRENSER).

OBJECTIVES: To assess fibromyalgia (FM) prevalence in a large cohort of primary Sjogren's syndrome patients (pSS) from a National Database. METHODS: Data included in the national retrospective register of pSS patients of the Spanish Society of Rheumatology (SJOGRENSER) were analysed. RESULTS: 437 pSS patients were included and a 14.6% of FM prevalence was found. FM-pSS patients significantly showed more constitutional, fatigue and arthralgia symptoms, splenomegaly, genital, skin and ear involvement and dyslipidaemia (p<0.05), as well as higher ESSPRI and SSDAI scores (p<0.01). Several symptomatic treatments were more frequently used in FM-pSS patients. No differences were observed in laboratory markers, imaging techniques or histologic inflammatory findings. Patients with FM showed statistically more fatigue than pSS without FM. In the multivariate logistic regression analysis several features were associated to pSS-FM patients. CONCLUSIONS: We show data on a reliable prevalence of FM in pSS patients and its multiple associated factors along with the presence of higher disease activity scores than patients who did not show FM. The presence of fatigue, arthralgia, constitutional symptoms and dyslipidaemia were more likely to coexist in pSS-FM patients.