In total, 153 patients ( mean age 41.8 years; 56.86% males) were included in this study. Renal biopsy was performed in 62 cases of renal biopsy, including 16 cases of IgA nephropathy. Based on MBPS defined as ≥35 mmHg, patients were divided into a two groups: with MBPS (n = 50) and without MBPS (n = 103). Demographic data, risk factors and blood pressure measurements of the patients in the two groups are presented in Table 1 and Table 2. Body mass index and creatinine levels were Significantly higher in patients with MBPS. In addition, 24-h systolic BP and 24-h PP as well as daytime systolic and diastolic BP were significantly higher in CKD patients with MBPS, while HDL levels were significantly lower. Hypertension was also more common in CKD patients with MBPS.
Table 1
Comparison of general data for CKD patients with or without MBPS.
Characteristics
|
Morning blood pressure surge group (n = 50)
|
Normal morning blood pressure surge group (n = 103)
|
t/c²
|
P
|
Age (y)
|
41.74±12.53
|
41.72±13.21
|
-0.10
|
0.992
|
Sex (male %)
|
32 (64.0%)
|
55 (53.4%)
|
1.079
|
0.299
|
BMI (kg/m2)
|
25.55±3.37
|
24.30±3.79
|
-1.983
|
0.049*
|
Hypertension (%)
|
35 (85.46%)
|
38 (36.89%)
|
14.788
|
0.000*
|
CKD pathological classification IgA nephropathy Other classification
|
|
|
5.070 0.024*
|
13(26.0%)
|
12(11.6%)
|
38(74.51%)
|
90(88.23%)
|
BUN ( mmol/l)
|
5.57 (4.69, 7.40)
|
5.51 (4.27, 7.90)
|
0.695
|
0.719
|
Creatinine (mmol/l)
|
106.0 (85.2, 127.3)
|
88.4 (65.0, 128.0)
|
1.477
|
0.025*
|
Uric acid (mmol/L)
|
388.32±98.85
|
366.58±105.30
|
-1.221
|
0.224
|
Phosphorus (mmol/L)
|
1.20±0.36
|
1.17±0.37
|
-0.439
|
0.661
|
Calcium (mmol/L)
|
2.27±0.17
|
2.24±0.20
|
-0.725
|
0.470
|
Glucose (mmol/L)
|
5.41±1.41
|
5.53±1.92
|
0.385
|
0.701
|
eGFR (ml/min/1.73/m2)
|
73.4 (48.6, 92.8)
|
83.6(47.5, 113.2)
|
1.168
|
0.245
|
Albumin (g/L)
|
35.5 (29.4, 39.1)
|
33.3 (21.7, 38.3)
|
1.311
|
0.064
|
Hemoglobin (g/L)
|
142 (128, 153)
|
135 (123, 150)
|
0.973
|
0.300
|
Total chol. (mmol/L)
|
2.12 (1.30, 3.15)
|
1.90 (1.15, 2.65)
|
0.864
|
0.446
|
Triglyceride (mmol/L)
|
4.94 (4.09, 6.37)
|
4.92 (4.06, 6.69)
|
0.490
|
0.970
|
HDL (mmol/L)
|
1.00±0.26
|
1.16±0.60
|
2.345
|
0.020*
|
LDL (mmol/L)
|
2.92±1.55
|
3.20±1.75
|
0.958
|
0.340
|
24-h Urine protein (g/24 h)
|
1.70 (0.80, 2.94)
|
1.59 (0.72, 3.57)
|
0.765
|
0.602
|
24-h SBP (mmHg)
|
122.5 (116.0, 135.3)
|
116.0 (107.0, 129.0)
|
1.547
|
0.017*
|
dSBP (mmHg)
|
125.0 (117.8, 138.0)
|
119.0 (109.0, 132.0
|
1.395
|
0.041*
|
nSBP (mmHg)
|
117.90±14.63
|
115.75±19.34
|
-0.696
|
0.488
|
24-h DBP (mmHg)
|
78.26±8.60
|
74.79±11.42
|
-1.903
|
0.059
|
dDBP (mmHg)
|
80.48±8.50
|
76.74±11.41
|
-2.058
|
0.041*
|
nDBP (mmHg)
|
72.94±9.47
|
72.92±12.90
|
-0.009
|
0.993
|
24-h PP(mmHg)
|
45.5 (40.0, 50.3)
|
40.0 (36.0, 49.0)
|
1.431
|
0.033*
|
dPP (mmHg)
|
46.0 (40.0, 50.3)
|
41.0 (37.0, 50.0)
|
1.431
|
0.033*
|
nPP (mmHg)
|
44.0 (38.8, 51.3)
|
40.0 (36.0, 48.0)
|
1.301
|
0.068
|
BUN, blood urea nitrogen; eGFR, estimated glomerular filtration rate; HDL, high-density lipoprotein; LDL, low-density lipoprotein; DBP, diastolic blood pressure; dDBP, daytime DBP; nDBP, night-time DBP; SBP, systolic blood pressure; dSBP, daytime SBP; nSBP, night-time SBP; PP, pulse pressure; nPP, night-time PP; dPP, daytime PP.
|
Table 2
Comparison of heart function index in CKD patients with or without MBPS.
|
Morning blood pressure surge group (n = 50)
|
Normal morning blood pressure surge group (n = 103)
|
t/c²
|
P
|
IVST (mm)
|
9.02±0.96
|
8.73±0.92
|
-1.815
|
0.071
|
LVPW (mm)
|
9.0 (8.0, 9.3)
|
9.0 (8.0, 9.0)
|
0.625
|
0.829
|
LVEF (%)
|
69.1 (65.7, 72.6)
|
69.0 (65.9, 71.2)
|
0.783
|
0.572
|
LVDd (mm)
|
48.0 (45.8, 50.0)
|
48.0 (45.0, 50.0)
|
0.629
|
0.824
|
*,means P <0.05; IVST, ventricular septal thickness; LVPW, left ventricular posterior wall thickness; LVDd, left ventricular end-diastolic diameter; LVEF, left ventricular ejection fraction; LVMI, left ventricular mass index.
During the follow-up (mean 4.3 years, range 1–6.7 years), 34 patients (19 males) experienced endpoint events (Table 3). In the group without MBPS, eight cardiovascular events and five strokes occurred with an incidence rate of 16.5%, including two deaths. In the group with MBPS, there were 17 endpoint events (6 cardiovascular events, 3 strokes, and 8 ESRD), with an incidence rate of 34%.
Kaplan-meier survival analysis showed that the incidence of Cardiovascular and cerebrovascular events, end-stage renal disease and death in the morning peak blood pressure group was significantly higher (log rank=4.124,P<0.05) than those in the normal morning peak blood pressure group in Figure 1. Cox regression univariate analysis showed that Hypertension,phosphorus,calcium,Creatinin,eGFR,Albumin,Hemoglobin,24HSBP,dSBP,nSBP,MBPS,dPP,nPP,Ventricular septal thickness,left ventricular posterior wall thickness,left ventricular end-diastolic diameter and left ventricular mass index were significantly associated with increased cardiovascular, Cerebrovascular,end-stage renal disease and death risk in Table 4. We performed cox regression multivariate analyses including Age,calcium, Hypertension,phosphorus,Creatinin,eGFR,Albumin,Hemoglobin,24HSBP,dSBP,nSBP,MBPS,24hPP,dPP,nPP,Ventricular septal thickness,left ventricular posterior wall thickness,left ventricular end-diastolic diameter and left ventricular mass index. Results of multivariate analyses are reported in Table 5. After adjustment for these covariates, the risk of Cardiovascular and cerebrovascular events, end-stage renal disease and death remained significantly higher in patients with MBPS [hazard ratio (HR) and 95% confidence interval (CI) 3.124 (1.096–9.130)]. Among the other variables, 24-h SBP, nPP, and dPP remained significantly associated with outcome in patients of CKD [1.789 (1.205–2.654), 1.710 (1.200–2.437), and 1.318 (1.096–1.586), respectively].
Table 3
Endpoint events in the two groups during the follow-up.
Table 4
Risk of endpoint events in univariate analysis.
|
Univariate regression analysis
|
Odds ratio
|
95% CI
|
P
|
Age, y
|
1.02
|
0.10–1.05
|
0.087
|
Males, n (%)
|
1.08
|
0.55–2.135
|
0.817
|
Hypertension (yes)
|
2.238
|
1.11–4.53
|
0.025*
|
Phosphorus ( mmol/L)
|
3.520
|
2.17–5.71
|
0.000*
|
Calcium ( mmol/L)
|
-0.022
|
0.01–0.08
|
0.000*
|
Glucose ( mmol/L)
|
1.142
|
0.96–1.36
|
0.136
|
BUN ( mmol/L)
|
1.073
|
1.05–1.10
|
0.000*
|
Creatinine ( mmol/L
|
1.001
|
1.001–1.002
|
0.000*
|
eGFR ( ml/min/1.73/m2)
|
0.973
|
0.960–0.980
|
0.000*
|
Uric Acid ( mmol/L)
|
1.003
|
1.0–1.006
|
0.000*
|
Albumin ( g/L)
|
0.908
|
0.88–0.94
|
0.000*
|
Hemoglobin ( g/L)
|
0.956
|
0.94–0.97
|
0.000*
|
MBPS ( 10 mmHg)
|
1.979
|
1.01–3.89
|
0.047*
|
24-h SBP ( 10 mmHg)
|
1.022
|
1.00–1.04
|
0.047*
|
dSBP ( 10 mmHg)
|
1.022
|
1.00–1.04
|
0.047*
|
nSBP ( 10 mmHg)
|
1.020
|
1.00–1.04
|
0.050
|
24-h DBP ( 10 mmHg)
|
1.026
|
0.99–1.06
|
0.166
|
dDBP ( 10 mmHg)
|
0.359
|
1.017–1.98
|
0.155
|
nDBP ( 10 mmHg)
|
1.023
|
1.00–1.05
|
0.105
|
24-hPP ( 10 mmHg)
|
1.026
|
0.97–1.06
|
0.090
|
dPP ( 10 mmHg)
|
1.043
|
1.01–1.08
|
0.013*
|
nPP ( 10 mmHg)
|
1.042
|
1.01–1.08
|
0.012*
|
IVST (mm)
|
1.607
|
1.24–2.08
|
0.000*
|
LVPW (mm)
|
1.599
|
1.24–2.10
|
0.000*
|
LVEF (%)
|
0.979
|
0.95–1.009
|
0.172
|
LVDd (mm)
|
1.280
|
1.14–1.44
|
0.000*
|
LVMI (g/m2)
|
1.033
|
1.02–1.05
|
0.000*
|
*,means P <0.05; CI, confidence interval; BUN, blood urea nitrogen; eGFR, estimated glomerular filtration rate; HDL, high-density lipoprotein; LDL, low-density lipoprotein; DBP, diastolic blood pressure; dDBP, daytime DBP; nDBP, night-time DBP; SBP, systolic blood pressure; dSBP, daytime SBP; nSBP, night-time SBP; PP, pulse pressure; nPP, night-time PP; dPP, daytime PP; IVST, ventricular septal thickness; LVPW, left ventricular posterior wall thickness; LVDd, left ventricular end-diastolic diameter; LVEF, left ventricular ejection fraction; LVMI, left ventricular mass index.
Table 5
Risk of endpoint events in multivariate analysis.
|
Multivariate regression analysis
|
Odds ratio
|
HR (95% CI)
|
P
|
Age ( years)
|
——
|
——
|
——
|
Hypertension (yes)
|
——
|
——
|
——
|
Phosphorus (↑mmol/L)
|
——
|
——
|
——
|
Calcium (↑mmol/L)
|
——
|
——
|
——
|
Glucose (↑mmol/L)
|
——
|
——
|
——
|
BUN (↑mmol/L)
|
——
|
——
|
——
|
Creatinine (↑mmol/L
|
——
|
——
|
——
|
eGFR (↑ml/min/1.73/m2)
|
——
|
——
|
——
|
Uric acid (↑mmol/L)
|
——
|
——
|
——
|
Albumin (↑g/L)
|
——
|
——
|
——
|
Hemoglobin (↑g/L)
|
——
|
——
|
——
|
MBPS (↑10 mmHg)
|
3.124
|
3.124 (1.096–9.130)
|
0.037*
|
24-h SBP (↑10 mmHg)
|
1.789
|
1.789 (1.205–2.654)
|
0.004*
|
24-h PP (↑10 mmHg)
|
——
|
——
|
——
|
dPP (↑10 mmHg)
|
1.710
|
1.710 (1.200–2.437)
|
0.003*
|
nPP (↑10 mmHg)
|
1.318
|
1.318 (1.096–1.586)
|
0.003*
|
IVST (mm)
|
——
|
——
|
——
|
LVPW (mm)
|
——
|
——
|
——
|
LVEF (%)
|
——
|
——
|
——
|
LVDd (mm)
|
——
|
——
|
——
|
LVMI (g/m2)
|
——
|
——
|
——
|
*,means P <0.05.