The relationship between brain-derived neurotrophic factor levels, oxidative and nitrosative stress and depressive symptoms: a study on peritoneal dialysis

Figures & data

Table 1. Demographic characteristics of PD patients and controls.

	PD patients (n = 83)	Controls (n = 84)
Age (years)	51.20 ± 12.30 (22–65)	37.50 ± 7.00 (24–52)
Female/male	44/39	59/25
Total dialysis  duration (months)	50.31 ± 35.79 (3–156)	–

Note: Values are expressed as mean ± SD (minimum–maximum).

Table 2. Comparison of BDNF, NO, MDA, SOD and GSH levels (means ± SD) between PD patients and controls.

	PD patients (n = 83)	Controls (n = 84)	p Values
MDA (µmol/L)	0.70 ± 0.16	0.57 ± 0.08	<0.001
GSH (mg/dL)	34.47 ± 4.56	47.94 ± 7.00	<0.001
SOD (U/L)	2.59 ± 0.61	10.67 ± 2.80	<0.001
NO (µmol/L)	22.66 ± 4.43	13.91 ± 11.71	<0.001
BDNF (pg/mL)	281.32 ± 179.02	781.50 ± 230.70	<0.001

Notes: BDNF, brain-derived neurotrophic factor; NO, nitric oxide; MDA, malondialdehyde; SOD: superoxide dismutase; and GSH: glutathione.

Table 3. Comparision of BDNF, NO, MDA, SOD and GSH levels (means ± SD) of PD patients between with and without EDS.

	With EDS patients (n = 28)	Without EDS patients (n = 55)	p Values
MDA (µmol/L)	0.78 ± 0.13	0.67 ± 0.16	0.008
GSH (mg/dL)	33.99 ± 4.29	34.69 ± 4.71	0.529
SOD (U/L)	2.53 ± 0.35	2.62 ± 0.72	0.526
NO (µmol/L)	23.35 ± 6.11	22.33 ± 3.39	0.347
BDNF (pg/mL)	206.81 ± 140.31	323.90 ± 225.82	<0.001

Notes: BDNF, brain-derived neurotrophic factor; NO, nitric oxide; MDA, malondialdehyde; SOD, superoxide dismutase; GSH, glutathione; and EDS: elevated depressive symptoms.

Table 4. Spearman correlation coefficients (r) between BDI scores and analyzed parameters in PD patients and those with EDS.

	r	p
PD patients with EDS (n = 28)
MDA µmol/L	−0.114	0.597
GSH mg/dL	−0.010	0.961
SOD U/L	−0.050	0.803
NO µmol/L	−0.071	0.736
BDNF pg/mL	0.268	0.167
PD patients (n = 83)
MDA µmol/L	0.320	0.005
GSH mg/dL	−0.047	0.684
SOD U/L	0	0.998
NO µmol/L	0.041	0.722
BDNF pg/mL	−0.312	0.004

Notes: BDI, Beck Depression Inventory.

Table 5. Association between BDNF and O&NS levels: results of linear regression analyses.

	PD patients with EDS (n = 28)		PD patients (n = 83)
	BDNF
	β-coefficient (95% CI)	p Value	β-coefficient (95% CI)	p Value
MDA	15.53 (−421.09 to 452.15)	0.941	18.65 (−251.28 to 288.58)	0.891
GSH	−1.91 (−13.02 to 9.20)	0.723	−3.98 (−13.99 to 6.03)	0.430
SOD	−63.87 (−229.84 to 102.11)	0.431	78.95 (2.63 to 155.26)	0.043
NO	−0.70 (−12.34 to 10.94)	0.901	−5.03 (−15.67 to 5.61)	0.349

Notes: CI, confidence interval; BDNF, brain-derived neurotrophic factor; and O&NS, oxidative and nitrosative stress.