Fibromyalgia: its prevalence and impact on the quality of life on a hemodialyzed population.

Fibromyalgia syndrome (FMS) is characterized by widespread musculoskeletal pain. It has negative effects on quality of life and has been poorly investigated in specific populations. Our aim was to determine the prevalence of FMS in Brazilian hemodialysis (HD) patients and to investigate its effects on the quality of life. We investigated 311 patients on HD who were submitted to physical examination towards the classification of FMS. All subjects from FMS and control groups were submitted to laboratorial investigation and completed questionnaires of quality of life. The prevalence of FMS was 3.9%, which was close to that of the general population. Most patients were females and from non-Caucasian races. No difference between FMS and control groups was observed regarding race, dialysis adequacy, nutritional status and level of schooling. Ionized calcium was higher in the FMS group than in the control group. There was no association between FMS and secondary hyperparathyroidism. On the other hand, FMS was associated with worse quality of life, depression and anxiety. In conclusion, the prevalence of FMS in HD patients was similar to that of the general population. It was associated with decreasing quality of life in HD patients, in addition to higher degrees of depression and anxiety. No laboratory tests could identify FMS patients on HD. Fibromyalgia syndrome subsequently follows without a well-established mechanism of pathogenesis, and seems to be due to multifactorial causes. Its true impact on the quality of life of HD patients deserves more attention by nephrologists.