Respostas autonômicas cardíacas durante e após esforço máximo em mulheres com fibromialgia

Abstract

Fibromyalgia (FM) is a rheumatic disease characterized by widespread chronic pain. It is believed that patients with FM have an autonomic dysfunction. However, it is not clear whether abnormal heart rate (HR) and HR variability (HRV) responses to maximal effort occur even in FM patients with similar physical performance to healthy individuals. Thus, the aim of this study was to verify the response of cardiac autonomic indexes at baseline, during and after a maximal incremental test in women with FM and to compare those with healthy women matched by anthropometric characteristics and physical performance on incremental test. Initially, twenty women diagnosed with FM and seventeen healthy women were recruited. In a single visit to the laboratory, the participants performed anthropometric evaluation and a maximal incremental test. Participants started the exercise with an initial workload of 15 watts, and the researchers increased the power 15 watts every minute until exhaustion. After all evaluations, the two groups were matched according to their physical characteristics and performance in the maximal incremental test. Thus, the study sample included 13 women diagnosed with FM (age: 46.2 ± 11.9 years; body mass index - BMI: 27.4 ± 4.5 kg/m2) and 14 healthy control women (CON: age: 47.1 ± 7.6 years; BMI: 26.9 ± 3.5 kg/m2). The HRV was continuously monitored at baseline and after (post-exercise recovery) the maximal incremental test. In addition, the HR response during exercise was evaluated through the chronotropic reserve and HR recovery was calculated as the difference in HR after 30, 60, 120, and 180 seconds of recovery in relation to peak HR during exercise. At baseline, the FM group had significantly lower parasympathetic index RMSSD compared to CON group (FM: 20.2 ± 8.3 ms vs. CON: 29.3 ± 13.7 ms; p = 0.009). On maximal incremental test, the chronotropic reserve response was significantly lower in the FM group (78.3 ± 12.2%) compared to the CON group (87.7 ± 8.2%; p = 0.025). The HR recovery were lower in the FM group after 30s (FM: 19.1 ± 7.9 bpm vs. CON: 27.4 ± 10.1 bpm; p = 0.026) and 180s (FM: 51. 5 ± 12.8 bpm vs. CON: 60.7 ± 11.4 bpm; p = 0.058) compared to the CON group. However, there was no significant difference between groups for HRV indexes on post-exercise recovery (p > 0.05). These findings suggest that women with FM have lower vagal tonus at baseline and reduced chronotropic responses during and after exercise, even with similar physical performance to healthy women.