Do serum biomarker levels correlate with anxiety disorders?

Table 1 Comparison of serum brain-derived neurotrophic factor, mature brain-derived neurotrophic factor, brain-derived neurotrophic factor precursor, aquaporin-4, and glycogen synthase kinase-3β levels between the two groups (mean ± SD)

Characteristics	Case group (n = 31)	Control group (n = 31)	P value	t value	Effect size (Cohen′s d)
BDNF (ng/mL)	13.21 ± 6.18	21.52 ± 6.48	< 0.05	-5.167	1.312
mBDNF (pg/mL)	537.01 ± 188.80	874.42 ± 463.69	< 0.05	-3.752	0.953
proBDNF (pg/mL)	1061.49 ± 451.74	729.10 ± 152.44	< 0.05	3.882	0.986
AQP4 (ng/mL)	39.23 ± 19.65	53.45 ± 12. 99	< 0.05	-3.361	0.854
GSK3β (pg/mL)	939.69 ± 249.02	771.28 ± 391.72	< 0.05	2.020	0.513

AQP4: Aquaporin-4; GSK3β: Glycogen synthase kinase-3β; BDNF: Brain-derived neurotrophic factor; mBDNF: Mature brain-derived neurotrophic factor; proBDNF: Brain-derived neurotrophic factor precursor.

Table 2 Diagnostic value of serum brain-derived neurotrophic factor, mature brain-derived neurotrophic factor, brain-derived neurotrophic factor precursor, aquaporin-4, and glycogen synthase kinase-3β levels in anxiety disorder

Group	AUC	95%CI	Sensitivity	Specificity	Cut-off value	P value
BDNF	0.8200	0.7189-0.9210	0.8065	0.6452	15.26	< 0.05
mBDNF	0.7211	0.5891-0.8532	0.5484	0.9032	776.20	< 0.05
proBDNF	0.7430	0.6106-0.8754	0.9677	0.5806	938.30	< 0.05
AQP4	0.7170	0.5877--0.8462	1.0000	0.4194	32.84	< 0.05
GSK3β	0.6452	0.5011-0.7892	0.4839	0.9355	640.10	< 0.05
Combined diagnosis	0.9698	0.9360-1.000	1.0000	1.0000	/	< 0.05

Optimal cut-off values were determined by the maximum Youden index (sensitivity + specificity - 1) based on raw serum concentrations. The combined diagnosis was constructed using multiple logistic regression. AQP4: Aquaporin-4; GSK3β: Glycogen synthase kinase-3β; BDNF: Brain-derived neurotrophic factor; mBDNF: Mature brain-derived neurotrophic factor; proBDNF: Brain-derived neurotrophic factor precursor.

Table 3 Correlation analysis of serum brain-derived neurotrophic factor, mature brain-derived neurotrophic factor, and brain-derived neurotrophic factor precursor levels in patients with anxiety disorder

	r value	P value
BDNF-mBDNF	0.6575	< 0.05
BDNF-proBDNF	0.5750	< 0.05
mBDNF-proBDNF	0.7865	< 0.05

BDNF: Brain-derived neurotrophic factor; mBDNF: Mature brain-derived neurotrophic factor; proBDNF: Brain-derived neurotrophic factor precursor.