Association between serum ferritin level and fibromyalgia syndrome.

BACKGROUND/
OBJECTIVES: Iron is essential for a number of enzymes involved in neurotransmitter synthesis. Analysis of cerebrospinal fluid in fibromyalgia syndrome (FMS) has shown a reduction in the concentration of biogenic amine metabolites, including dopamine, norepinephrine and serotonin. This study aimed to investigate the association of ferritin with FMS. SUBJECTS/
METHODS: A total of 46 patients with primary FMS participated in this case-control study, and 46 healthy females who were age matched to the patients were used as the control group. Venous blood samples collected from all subjects were used to evaluate serum ferritin, vitamin B12 and folic acid levels.
RESULTS: The mean serum ferritin levels in the fibromyalgia (FM) and control groups were 27.3+/-20.9 and 43.8+/-30.8 ng/ml, respectively, and the difference was statistically significant (P=0.003). Binary multiple logistic regression analysis with age, body mass index, smoking status and vitamin B12, as well as folic acid and ferritin levels showed that having a serum ferritin level <50 ng/ml caused a 6.5-fold increased risk for FMS.
CONCLUSIONS: Our study implicates a possible association between FM and decreased ferritin level, even for ferritin in normal ranges. We suggest that iron as a cofactor in serotonin and dopamine production may have a role in the etiology of FMS.