Fibroblast Growth Factor 2 Levels in Patients with Major Depressive Disorder: A Meta-analysis.

Fibroblast growth factor 2 (FGF2) plays an essential role in neurogenesis, oxidative stress, and emotional behavior. However, the evidence regarding the role of FGF2 in the pathophysiology of depression remains limited and inconclusive. We conducted a systematic review and meta-analysis to investigate peripheral blood FGF2 levels in patients with depression and healthy controls. The PubMed and Web of Science databases were used to identify relevant articles for systematic retrieval. Eight studies involving 310 patients with depression and 268 healthy controls were included in this meta-analysis. A random-effects meta-analysis showed no difference in peripheral blood fibroblast growth factor 2 (FGF2) levels between patients with depression and HC (Hedges' g =  - 0.288, 95% CI =  - 0.828 to 0.253, P = 0.297), but there was heterogeneity (Q = 55.719, df = 7, I2  = 87.437, P = 0.000). Subgroup analysis showed no statistically significant differences in the blood (serum/ plasma) and assay (ELISA/ no ELISA) FGF2 levels between all patients with depression and controls; however, there was heterogeneity. The meta-regression analysis showed that age, sex, sample size, depression severity, and publication year did not affect the results. Patients with different subtypes may have mild-to-severe symptoms or a different course of the disease, affecting neurotrophic factor levels. We could not obtain sufficient data from different studies to control for variables. Although the relationship between our findings and the pathophysiology of depression and the role of FGF2 in disease development remains to be determined, FGF2 may be a potential biomarker for depression.