Baroreflex sensitivity assessment in patients with type 2 diabetes during orthostatic challenge

Abstract

Baroreflex dysfunction has been demonstrated in fibromyalgia syndrome (FMS). However, there are few studies evaluating the effectiveness of hydrotherapy programs on cardiovascular autonomic control in this population. This study evaluates the effects of a 16-week hydrotherapy program on baroreflex sensitivity (BRS) in women with FMS. Eight women with FMS took part in the study. The electrocardiogram, non-invasive finger blood pressure and respiratory activity were continuously recorded for all participants during 15 min in supine and 15 min in orthostatic (active standing) positions, before and after a 16week hydrotherapy program (Post16). The BRS was estimated via cross-spectral analysis, computed as the square root of the ratio of the low frequency (LF) band power of heart period on the LF power of systolic arterial pressure (αLF). The hydrotherapy program comprised 32 sessions of 45 min of pool exercises twice a week, for 16 weeks. At baseline there was no significant difference for the αLF index between supine and orthostatic positions (p N 0.05). At Post16, there was a significant decrease of the αLF during orthostatic stimulus compared to the supine position (p b 0.05). There was no significant difference between baseline and Post16 for αLF in supine position (p N 0.05). However, the αLF was lower at Post16 during orthostatic posture compared to the baseline (p b 0.05). The variation of αLF between supine and orthostatic postures (ΔαLF) was higher at Post16, compared to the baseline (ΔαLF baseline: -1.7 ± 3.5; Post16: -6.9 ± 5.7; p b 0.05). A 16-week hydrotherapy program improved the cardiac baroreflex control response to the orthostatic stimulus in women with FMS.