Evaluation of serum levels of neurotrophin 4 and brain-derived nerve growth factor in uremic pruritus patients

Figures & data

Table 1 Clinical and laboratory data of the participants

	Group A n=60	Group B n=60	Group C n=60	F	P-value
Age (years)	51±10	46±17	47±16	1.95	0.1448
Sex (male/female)	28/32	29/31	27/33	χ^2=0.134	0.935
BMI (kg/m^2)	23.3±4.5	22.4±5.1	24.5±5.7	2.54	0.082
Hemoglobin (g/dL)	8.7±1.8	8.9±1.7	12.3±2.3	64.52	<0.0001
Calcium (md/dL)	7.9±1.6	7.3±1.9	7.5±2.5	1.35	0.261
Phosphors (mg/dL)	5.9±1.6	6.2±1.8	6.3±1.7	0.898	0.409
Parathyroid (pg/mL)	498±333.6	518±389.5	51.4±12.6	47.6	<0.0001
Urea (mg/dL)	164.7±47.9	170.5±44.5	24.6±12.4	277.4	<0.0001
Creatinine (mg/dL)	6.4±2.9	7.2±2.3	0.3±0.5	205.20	<0.0001
NT-4 (pg/mL)	7.32±4.2	5.04±3.91	3.07±2.65	20.38	0.0001
BDNF (pg/mL)	3.29±3.11	2.54±2.05	1.9±1.6	6.046	0.0029
	Group A vs Group C		Group B vs Group C
	t	P-value	t	P-value
NT-4 (pg/mL)	6.63	<0.0001	3.23	0.0016
BDNF (pg/mL)	3.079	0.0026	2.204	0.0294

Notes: Group A: uremic patients under regular hemodialysis with pruritus; Group B: uremic patients under regular hemodialysis without pruritus; Group C: normal controls. Comparison between the three groups was done by ANOVA test, while comparison between the two groups was done by simple statistical analysis t-test. P≤0.05 is significant, while >0.05 is nonsignificant.

Abbreviations: BDNF, brain-derived nerve growth factor; BMI, body mass index; NT-4, neurotrophin-4.

Table 2 Comparison between uremic patients with pruritus vs uremic patients without pruritus

	Group A	Group B	t	P-value
Age (years)	51±10	46±17	1.96	0.999
Sex (male/female)	28/32	29/31	χ^2=0.033	0.855
BMI (kg/m^2)	23.3±4.5	22.4±5.1	1.025	0.83
Hemoglobin (g/dL)	8.7±1.8	8.9±1.7	0.626	0.33
Calcium (mg/dL)	7.9±1.6	7.3±1.9	1.871	0.905
Phosphors (mg/dL)	5.9±1.6	6.2±1.8	0.965	0.816
Parathyroid (pg/mL)	498±333.6	518±389.5	0.302	0.882
Urea (mg/dL)	164.7±47.9	170.5±44.5	0.687	0.4933
Creatinine (mg/dL)	6.4±2.9	7.2±2.3	1.674	0.0967
NT-4 (pg/mL)	7.32±4.2	5.04±3.9	3.081	0.0026
BDNF (pg/mL)	3.29±3.11	2.54±2.05	1.56	0.1215
Duration of hemodialysis (months)	49±43	41±35	1.118	0.266

Notes: Comparison between the two groups was by simple statistical analysis t-test. P≤0.05 is significant, while >0.05 is nonsignificant.

Abbreviations: BDNF, brain-derived nerve growth factor; BMI, body mass index; NT-4, neurotrophin-4.

Table 3 Serum level of NT-4 and BDNF according to the severity of pruritus by 5D score

	Moderate (5D score 10–15) n=18	Severe (5D score >15–25) n=19	Very severe (>25) n=23	F	P-value
NT-4	5.6±2.3	6.2±4.9	8.9±5.3	3.257	0.0458
BDNF	2.9±1.9	3.2±2.7	3.7±3.4	0.4304	0.6523

Notes: Comparison between the three groups was done by ANOVA test, while comparison of the two groups was by simple t-test. P≤0.05 is significant, while >0.05 is nonsignificant.

Abbreviations: BDNF, brain-derived nerve growth factor; NT-4, neurotrophin-4.

Figure 1 Correlation between 5D score and serum NT-4.

Abbreviation: NT-4, neurotrophin-4.

Table 4 Correlations between severity of pruritus and different variables

	r	P-value
Age	0.175	0.528
Sex	0.0191	0.33
Duration of hemodialysis	–0.122	0.64
BMI	–0.242	0.23
Hemoglobin	0.016	0.932
Parathyroid	0.024	0.897
Urea	0.124	0.54
Creatinine	0.085	0.683
Calcium	0.163	0.754
Phosphorus	0.287	0.239
NT-4	0.385	0.024
BDNF	0.642	0.056

Notes: r, Pearson correlation coefficient. P≤0.05 is significant; P>0.05 is nonsignificant.

Abbreviations: BDNF, brain-derived nerve growth factor; BMI, body mass index; NT-4, neurotrophin-4.