Autonomic Dysfunction at Rest and During Isometric Exercise in Women With Fibromyalgia

Abstract

Fibromyalgia (FM) is an idiopathic disease that affects mainly women. Studies have proposed that autonomic dysfunction may play a role in the development of FM. PURPOSE: To evaluate hemodynamic and cardiac autonomic responses to isometric handgrip (IHG) in healthy control women (HC: n=9) and women with FM (FM: n=1 1). METHODS: Eighteen women (48 ± 10 yr; mean ± SD) volunteered for this study. Heart rate (HR) variability and blood pressure (BP) were measured via continuous ECG and finger plethysmography (Finometer), respectively, during 2 min of rest and 2 min of IHG at 30% of maximal force. RESULTS: Age, weight, and body mass index were similar in both groups. Resting HR and normalized (nu) low-frequency (LFnu) were higher (p<0.05) while high-frequency (HFnu) power was lower (p<0.05) in the FM than in the HC group. There was a group × time interaction (p<0.05) for both LFnu and HFnu, such that LFnu increased (+35%) and HFnu decreased (−32%) in the HC group but not in the FM group. The increase in systolic BP (SBP) was significantly (p<0.05) greater in the HC (13%) than in the FM (8%) group. Diastolic BP (DBP) increased significantly (p<0.05) from rest to IHG in both groups. CONCLUSION: Women with FM have autonomic dysfunction as demonstrated by reduced vagal and increased sympathetic modulation of HR at rest. In addition, SBP and autonomic responses to isometric exercise were impaired in women with FM.Table