Levels of the neurotransmitter serotonin are decreased in pregnant women with fibromyalgia, a small study shows.
Serotonin is known to induce a feeling of happiness, vitality and euphoria. Its absence has been associated with depression, tiredness, and a nervous mood. In the brain, serotonin influences cognition, emotion, mood, and behavioral control, among others.
Previous studies have suggested that fibromyalgia may have a negative impact in pregnancy outcomes, but the number of studies examining the relationship between fibromyalgia and pregnancy is still low.
Now, a team of researchers proposed to investigate this possible relationship, and focused on the potential role of serotonin.
Previous work suggested that during pregnancy, serotonin synthesis and the activity declines. Interestingly, other studies have proposed that serotonin impairment in fibromyalgia contributes to the development of the disease.
Researchers performed a prospective case-control study with 277 pregnant women attending the Ankara University Faculty of Medicine, in Turkey, between January and June 2015. A fibromyalgia diagnosis was confirmed using the 2010 ACR diagnostic criteria.
Participants were asked to answer several questionnaires, including the Fibromyalgia Impact Criteria (FIQ), Widespread Pain Index (WPI), Symptom Severity Scale (SS), Beck Depression Inventory and Visual Analog Scale (VAS). In total, 150 pregnant women with a confirmed fibromyalgia diagnosis, and 127 pregnant women without the disease (control group) were evaluated.
Researchers also measured the levels of several markers important for muscle and bone metabolism, including glucose, calcium, phosphorus, parathyroid hormone (PTH), thyroid stimulant hormone (TSH), and the levels of serotonin.
The results showed that fibromyalgia has a negative impact in both physical and physiological parameters in pregnant women. Anxiety and depression were higher in pregnant women with fibromyalgia when compared to those without the disease.
Moreover, researchers found that the levels of serotonin were significantly lower in the fibromyalgia group than in the controls. Researchers also observed that lower levels of serotonin correlated with increased pain and physical limitation.
No differences were found between the groups regarding the levels of glucose, calcium, PTH and TSH.
Overall, the results show that serotonin levels are decreased in women with fibromyalgia, and that these levels are further reduced during pregnancy.
While these findings may suggest that lower serotonin may increase the risk for developing fibromyalgia, researchers found no statistically significant results to confirm this hypothesis.