Correlations between autonomic dysfunction and circadian changes and arrhythmia prevalence in women with fibromyalgia syndrome.

OBJECTIVE: It is known that increased sympathetic activity and decreased parasympathetic activity are present in patients with fibromyalgia syndrome (FMS). This study aims to investigate the correlations of autonomic dysfunction and differences in autonomic circadian activity with arrhythmia prevalence in women with FMS.

METHODS: Fifty female patients with FMS and 30 healthy female controls were included in this cross-sectional, case-controlled study. A 12-lead electrocardiogram and 24-hour Holter monitoring were performed in all patients to evaluate arrhythmias and autonomic function tests. Heart rate variability (HRV) parameters were utilized to detect autonomic dysfunction in patients with FMS. HRV measurements were performed in total 24-hour, day time (06:00-22:59), night time (23:00-05:59) periods and during autonomic tests (stand - supine, inspiration-expiration and Valsalva tests) using 24-hour Holter monitoring recordings. Student t-test , Mann-Whitney U and Pearson Chi-square tests were used for comparisons of the data between groups. The correlation of data was tested by using Spearman correlation analysis.

RESULTS: The mean ages of the patient and control groups were 38+/- 7.4 and 36+/- 8.1 years, respectively. In HRV measurements, high frequency (HF) power, was significantly decreased in the patient group as compared with control group (167.4 msec2 (107.0- 312.0) vs.314.5 msec2 (124.0- 905.0), p=0.017). The low frequency/HF ratio (LF/HF) values for total 24 hours (2.22+/- 0.18 vs. 1.22+/- 0.12, <0.001) and in the night time period (2.78+/- 1.97 vs.1.15+/- 0.77, <0.001) were found to be significantly higher in the patient group than in control one. The ratio of LF/HFDay / LF/HFNight was markedly higher in the control group (2.67 (1.22- 5.65) vs. 1.45 (0.83- 2.05), p=0.004). The prevalence (p=0.028) and total number (127.1+/- 21.4 vs. 187.3+/- 62.3, p=0.019) of supraventricular extrasystoles in 24-hour period was higher in the patient group.

CONCLUSION: The sympathetic activity was significantly increased and parasympathetic activity significantly decreased in FMS patients. Additionally, significant autonomic circadian activity changes were also detected in these patients. These autonomic changes might be linked to increased arrhythmia prevalence.