MEXICO DF, MEXICO. Fibromyalgia is a painful rheumatic condition that affects about 2 per cent of the population and is particularly prevalent among women. It is often accompanied by chronic fatigue syndrome and such symptoms as fatigue, anxiety, headaches, sleep disturbances and morning stiffness. Fibromyalgia has long been passed off as a "hysterical complaint" primarily because its origin is unknown, it is mainly a women's disease, and there is no effective treatment for it.
Mexican researchers have now produced what is perhaps the first evidence that fibromyalgia actually is a "real" disease and that it is intimately linked to a dysfunction of the autonomic nervous system. Their study involved 19 women (aged 26 to 60 years) and 19 healthy controls. Ten of the 19 fibromyalgia patients also had chronic fatigue syndrome. All study participants had their heart rate variability (HRV) measured while lying down (supine position) and immediately upon reverting to a standing position. HRV is a measure of the balance between the sympathetic (adrenergic) and parasympathetic (vagal) branches of the autonomic nervous system. The researchers noted a profound difference in the response to the change from supine to standing position. In the normal subjects it was accompanied by a 40 per cent increase in sympathetic activity while the fibromyalgia patients experienced a 24 per cent decrease in sympathetic activity. The researchers conclude that this difference is highly significant and may explain many of the symptoms of fibromyalgia particularly increased fatigue and a lowered pain threshold.
Hungarian researchers report similar findings in a study of 34 fibromyalgia patients.