Salt sensitivity of blood pressure in non-dialysis patients with chronic kidney disease

Figures & data

Table 1. General characteristics of the study population during basal conditions.

Subjects characteristic
Gender
Men, n (%)	80 (61.5%)
Women, n (%)	50 (38.5%)
Age, years	61.96 ± 13.27
Protopathy
Glomerulonephritis	42%
Diabetic nephropathy	38%
ANCA-related vasculitis	4%
Multicystic kidney disease	2%
Others	14%
eGFR, mL/min/1.73 m^2	21.08 (median)
SBP, mm Hg	138.55 ± 19.22
DBP, mm Hg	80.67 ± 10.87

Figure 1. The relationship between salt intake and SBP.

Table 2. The relationship of salt intake and blood pressure in different groups.

	SBP and the salt intake			DBP and the salt intake
Installments	Unstandardized coefficients (B)	Adjusted R square	p	Unstandardized coefficients (B)	Adjusted R square	p
Stage 1	−0.033	0.067	0.235	−0.004	−0.121	0.873
Stage 2	0.029	−0.024	0.434	0.004	−0.07	0.884
Stage 3	0.113	0.165	0.034	0.068	0.193	0.024
Stage 4	0.094	0.22	0.04	0.018	−0.008	0.391
Stage 5	0.88	0.101	0.014	0.013	−0.011	0.498

B: Unstandardized coefficients, p: Represents probability.

Figure 2. The regularity of SBP and dietary sodium intake with the change of eGFR.

Figure 3. The regularity of DBP and dietary sodium intake with the change of eGFR.

Table 3. Multivariate regression analysis of SBP and DBP. (Prior to stepwise analysis).

	SBP			DBP
	B	β	p	B	β	p
BMI	0.146	0.025	0.814	0.074	0.023	0.828
Age	0.004	0.003	0.979	−0.215	−0.274	0.008
Salt intake	0.034	0.168	0.159	0.003	0.028	0.813
U-Pro	1.036	0.138	0.194	−0.340	−0.085	0.433
24 h urine potassium	0.185	0.173	0.131	0.141	0.245	0.036
lgeGFR	−4.222	−0.232	0.036	−1.192	−0.122	0.272
lgDDD	1.834	0.067	0.511	−0.614	−0.042	0.686
Constant	132.588	—	0.000	93.471	—	0.000

Table 4. Results of stepwise regression analysis with SBP and DBP as dependent variables.

DV	IV	B	β	p
SBP	Salt intake	0.061	0.299	0.004
	lgeGFR	−3.436	−0.190	0.063
	Constant	140.832	—	0.000
DBP	Age	−0.195	−0.249	0.011
	Constant	94.174	—	0.000

Notes: DV, dependent variable; IV, independent variable. The relationship between the variable lgeGFR and salt intake SBP did not reach statistical significance (p < 0.05). But we still thought salt intake and lgeGFR were the main factors for SBP.

Table 5. The relationship between the dosage of the antihypertensive drugs (DDD) and salt intake.

	Stage 1	Stage 2	Stage 3	Stage 4	Stage 5
Adjusted R square	−0.113	0.048	0.004	0.385	0.227
Unstandardized coefficients (B)	0.000	0.007	−0.006	0.016	0.013
Unstandardized coefficients  (std. error)	0.003	0.006	0.006	0.004	0.005
Standardized coefficients (β)	−0.103	0.357	−0.322	0.644	0.519
p	0.778	0.231	0.334	0.001	0.023

Figure 4. Compare of the dosage of the antihypertensive drugs in every stage of CKD.

Table

Types of drugs	Names of drugs	DDD (mg)
Calcium channel blockers (CCB)	Nifedipine controlled released tablets nifedipine delayde-release tablets	30
	Amlodipine tablets	20
	Felodipine tablets	5
Angiotensin II receptor blocking drugs (ARB)	Valsartan capsules	80
	Losartan potassium tablets	100
Angiotensin-converting enzyme inhibitors (ACEI)	Benazepril tablets	10
	Enalapril tablets	10
β-blockers (β-RB)	Metoprolol tablets	50
Diuretics (DU)	Spironolactone	75
	Furosemide tablets	40
	Hydrochlorothiazide tablets	25
	Furosemide injection	40
	Torasemide injection	20
α-blockers (α-RB)	Alfuzosin tablets	10
Compound antihypertensive drugs	Carvedilol	25
	rbesartan and Hydrochlorothiazide tablets	162.5