August 1998
Pia Reinhard, Fritz Schweinsberg, Dorothee Wernet, and Ina Kötter
Abstract
Fibromyalgia (FM) is a chronic musculoskeletal pain syndrome of unknown etiology. The serum concentration of selenium (Se) was measured in 68 consecutive patients (nine male, mean age: 47 years; 59 female, mean age 49 years) with FM.
The age- and sex-matched control group included 97 female healthy blood donors (mean age 46 years). The method is based on high-performance liquid chromatography (HPLC) involving detection of the fluorescent diaminonaphthalene (DAN) derivate of selenite.
There was a statistical significant difference (P<0.05) in serum Se between control (median 77 μg/l; range: 50–118 μg/l) and patients (median 71 μg/l; range: 39–154 μg/l) groups in the region of Tübingen, Germany.
Introduction
Fibromyalgia (FM) (Goldenberg, 1994) is a chronic musculoskeletal syndrome characterized by diffuse pain and the presence of musculoskeletal tender points on physical examination. There is no evidence that synovitis or myositis are causes. Additionally, patients with FM suffer from a large and heterogeneous number of symptoms such as fatigue, headaches and irritable bowel syndrome. The etiology of FM is still unknown.
Selenium (Se) is a trace element essential for the activity of glutathione peroxidase (GPx) which catalyses the detoxification of hydrogen peroxide and organic hydroperoxides (Högberg and Alexander, 1986). Several historical studies have been reported from two human diseases associated with severe nutritional Se deficiency, a juvenile cardiomyopathy called Keshan disease (Ge and Yang, 1993) and a chondrodystrophy called Kaschin-Beck disease (Allander, 1994) which, like FM is a musculoskeletal noninflammatory disorder.
Low levels of Se have been shown in rheumatoid arthritis (Tarp, 1994) and psoriatic arthritis (Michaelsson et al., 1989). In our pilot study (n=40) (Kötter et al., 1995), it seemed that there is a tendency towards relatively low Se levels in FM.
This study was initiated to examine the Se status in FM compared with an age- and sex-matched control group in order to gain further insight into its etiology.
Subjects
A total of 68 patients with FM (mean age 47 years; 59 female, nine male) were consecutively recruited from the out-patient department of the Clinical Rheumatology, Section of the Medical University Clinic, Tübingen. These patients were diagnosed according to the criteria for the classification of FM determined by the American College of Rheumatology (ACR) (Wolfe et al., 1990).
A cohort of 97 female healthy blood donors (mean age 46 years) from the University of Tübingen’s blood bank served as an
Results and discussion
The Shapiro-Wilk W test for normality (Altman, 1991) yielded a moderate probability of 0.46 for the control group data while the female patient group data yielded a small probability of 0.004. So the control group data were compatible with a normal distribution, while the female patient group values were not. That is why we based our inferences on the median and not on the mean, hence the confidence intervals were calculated with the median (Altman, 1991).
The Se serum concentration of 68
Acknowledgements
The assistance of Pietsch-Breitfeld in the statistical analysis and of Koch for technical support is gratefully acknowledged.
