Autonomic dysfunction in women with fibromyalgia

In a recent issue of Arthritis Research & Therapy, Ribeiro and colleagues [1] present data that lend further support to the theory that women with fibromyalgia (FM) suffer from autonomic dysfunction in response to, and during recovery from, acute exercise. Alterations in autonomic function have been suggested to increase the risk for cardiovascular events and mortality [2]. While the data are not fully understood regarding the risk of premature cardiovascular disease in women with FM specifically, it appears that there is definitive evidence to support autonomic dysfunction at rest.The study by Ribeiro and colleagues examined cardiovascular responses during and after a maximal treadmill test in women with FM and healthy controls. Chronotropic incompetence, the inability to increase heart rate with increasing exercise intensities, was used as a measure of cardiac autonomic responses during the exercise bout. Meanwhile, heart rate recovery taken at 1 and 2 minutes post-exercise was used to assess recovery from the acute aerobic exercise bout.The major findings of this study were relatively novel. The present study reported that women with FM had a lower oxygen consumption (VO2max) than healthy controls, which has been reported previously [3]. More importantly, Ribeiro and colleagues reported that chronotropic reserve was significantly lower in women with FM than healthy controls. Furthermore, 57.1% of the women with FM presented chronotropic incompetence compared to none of the healthy controls. Lastly, there was a significant reduction in heart rate recovery at 1 minute and 2 minutes after the exercise bout in the women with FM compared to healthy controls, suggesting an inability of the parasympathetic system to recover.One of the main points highlighted in the paper by Ribeiro and colleagues is the lack of data regarding autonomic modulation during exercise in women with FM. The only study that I am aware of that has attempted to quantify autonomic function during