Investigation of the relationship of vitamin D levels and autonomic nervous system function in fibromyalgia syndrome

Background In this study, it was planned to examine the sympathetic skin response (SSR) in order to determine whether there is autonomic dysfunction in fibromyalgia syndrome (FMS). By comparing the obtained data with vitamin D levels; It is aimed to better understand the relationship between autonomic nervous system dysfunction and vitamin D levels in FMS syndrome. Material and Methods Between September 2021 and September 2022, 41 female patients who applied to Bolu Abant İzzet Baysal Physical Medicine and Rehabilitation Training and Research Hospital due to widespread pain and were diagnosed based on the American Collegue of Rheumatology (ACR) 2010 diagnostic criteria and 38 healthy controls were included in the study. The diagnoses of the patients were confirmed according to the ACR 2016 diagnostic criteria. After the clinical examination, all patients were evaluated for SSR in the electroneuromyography (ENMG) laboratory. The upper and lower extremities of all participants were recorded, SSR was studied, and amplitude and latency values were recorded. Vitamin D levels of all participants were recorded. All patients were also evaluated with Visual Analog Scale (VAS), Beck Depression Inventory (BDI), and Fibromyalgia Impact Questionnaire (FIA), and Short Form-36 (SF-36). Results The mean age of the individuals included in the study was 41.37±6.86 and vitamin D values were 18.32±8.07. In comparisons, latency values in all 4 extremities were found to be statistically higher in FMS patients than in healthy individuals. On the other hand, amplitude responses were found to be significantly higher only in the left lower extremity in the control group than in the FMS group. No statistically significant correlation was found between SSR and vitamin D levels, VAS, BDI, FIQ and SF-36 scores in fibromyalgia patients (p>0.05). Conclusions The results of this study support that there is a change in the sympathetic nervous system of patients with FMS, indicating autonomic dysfunction. However, no relationship was found between vitamin D levels and SSR. Further more extensive studies with larger patient populations are now needed. Key words: Autonomic dysfunction; Fibromyalgia; sympathetic skin response; vitamin D.