Effects of renal replacement therapy on fibromyalgia syndrome in patients with chronic kidney disease

Introduction: Although musculoskeletal disorders are among the major complications of chronic kidney disease (CKD), there are scarce data to investigate fibromyalgia syndrome (FMS) in these patients. We aimed to investigate the prevalence of FMS in the patients with CKD. Material and methods: A total of 289 (119 predialysis (PD), 85 hemodialysis (HD), 85 continuous ambulatory peritoneal dialysis (CAPD)) patients were included. Diagnosis of FMS was based on American College of Rheumatology (ACR) 1990 FMS criteria. Results: Mean age was 52±16 years (range 18-89 years). One-hundred-sixty-four (56.7%) of them were male. A total of 46 patients (10 male/36 female) (15.9%) were diagnosed FMS. The prevalence of FMS was 28.8% in females and 6.1% in males. Compared to males, females had a significantly higher rate of FMS (p≪0.001). The prevalence of FMS was 19.3% in PD group, 17.6% in the CAPD group, and 9.4% in the HD group. Although the frequency of FMS was lower in HD group compared to both the PD and the CAPD groups, the differences were not statistically significant (for HD vs PD, p=0.052; for HD vs CAPD, p=0.113). In PD group, hemoglobin (Hb) levels were significantly higher in patients with FMS than without FMS. Parathormone (PTH) levels were significantly lower in CAPD patients with FMS than without FMS. Although the prevalence of FMS was increased in PD and CAPD patients, this increase did not reach statistical significance. FMS was markedly more prevalent in female patients. While the Hb level was lower in the PD patients with FMS, PTH level was lower in the CAPD patients diagnosed with FMS. Conclusions: Our study demonstrated that the rate of FMS was higher in PD and CAPD patients compared to HD patients, although our results did not reach statistical significance. Among the entire demographic and laboratory parameters, female gender was found to be significant risk factor for development of FMS. Future multicenter studies which have large sample size are clearly needed to determine other factors related to development of FMS in patients with CKD.