Polymorphisms of brain-derived neurotrophic factor genes are associated with anxiety and body mass index in fibromyalgia syndrome patients

Objective: Fibromyalgia syndrome has been associated with familial clusters although the specific genetic predisposition
is not clear. Accordingly, studies concerning genetic factors associated with this disease are important. Brainderived
neurotrophic factor (BDNF) has been shown to play a role in patients with fibromyalgia syndrome, particularly
in mediating manifestations of pain and mood-related symptoms. Research on genetic factors, including genetic
variations or single nucleotide polymorphisms, especially related to BDNF in fibromyalgia is very limited. Therefore,
this study was aiming at determining the association of polymorphisms of BDNF, particularly rs2049046 (A>T) and
rs7124442 (A>G), with body mass index (BMI) and mood-related symptoms in FMS.
Results: In fibromyalgia syndrome cases, BDNF polymorphisms were associated with body mass index and anxiety
score, specifically rs7124442 (A>G) (Fisher’s exact test χ2; p < 0.05; odds ratio (OR): 1.02) and rs2049046 (A>T) (Fisher’s
exact test χ2; p < 0.05; OR: 0.55), respectively. Additionally, patients with fibromyalgia syndrome who have AA (95% CI
(8.71, 11.63)) and AT (95% CI (9.32, 11.74)) alleles of rs2049046 showed higher score of anxiety compared to patients
with TT (95% CI (3.98, 8.20) allele (ANOVA test; p < 0.01). These results suggest that BDNF polymorphisms (rs7124442
and rs2049046) are associated with body mass index and anxiety symptoms in patients with fibromyalgia syndrome.