Hormones and Fibromyalgia
Researchers also have taken the fact that fibromyalgia is more common in women than men and suggested that the sex hormone estrogen is involved. However, little correlation has been discovered. It also has been suggested that the lower levels of testosterone in women than in men is more likely involved since testosterone is involved in building muscle strength.
A team of researchers from Massachusetts found that cortisol levels are low in people with fibromyalgia. Cortisol is produced by the adrenal gland and affects many bodily systems. Low levels of cortisol are ever present in the body but we produce more during times of stress. When the body is deficient in cortisol, the symptoms of fibromyalgia are mirrored, such as:
- muscle pain
- abdominal distress
- thinking problems
- mood swings
- sleep disturbances
The research team from Massachusetts found that fibromyalgia patients produce less cortisol in response to stress than do healthy people, possibly having to do with a defect in the hypothalamic-pituitary-adrenal axis which controls cortisol production. It is not clear how important cortisol deficiency is in the onset or course of fibromyalgia. Giving patients corticosteroid medications does not improve the condition.
Genetics and Fibromyalgia
The relationship between children and parents having either fibromyalgia or other pain related problems has led some researchers to suggest a genetic cause. Particular genetic markers have been mentioned, but those markers have been different in different studies. Most recently HLA, human leukocyte antigen markers, have been implicated. Another study published in 1996 proposed that fibromyalgia is more common in people who have a family history of alcoholism and depression. Biological and genetic factors have been studied in these areas as well.
Relationship to Autoimmunity
Since fibromyalgia is often diagnosed in people with autoimmune diseases such as rheumatoid arthritis and lupus erythematosus, it has been theorized that fibromyalgia has an immune system basis too. One study indicated an increased number positive antinuclear antibody blood tests among people with fibromyalgia. This finding may be coincidental though since it is known that a small percentage of healthy people are also positive for antinuclear antibodies (ANA).
The high prevalence of fibromyalgia in the general population may suggest that its occurrence in people with autoimmune disease is purely coincidental. Conversely, some forms of the over 100 known types of arthritis may be related to muscle pain and fatigue. Some researchers conclude then that if physiologic stress is truly a factor in fibromyalgia, the physical and emotional toll of having a chronic disease may precipitate fibromyalgia in people with some arthritis-related diseases.
The Bottom Line - The Cause of Fibromyalgia Syndrome?
Fibromyalgia is most likely the result of different causes, only time will tell.
In terms of treating fibromyalgia syndrome, it can be compared to conditions such as hypertension - a condition not completely understood, yet treatable.
Fibromyalgia-Syndrome of the 90's, by Mary Anne Dunkin, Arthritis Today, September-October 1997