Cardiol Res

Cardiology Research, ISSN 1923-2829 print, 1923-2837 online, Open Access

Article copyright, the authors; Journal compilation copyright, Cardiol Res and Elmer Press Inc

Journal website http://www.cardiologyres.org

Original Article

Volume 11, Number 2, April 2020, pages 106-112

Correlation Between the Cardio-Ankle Vascular Index and Renal Resistive Index in Patients With Essential Hypertension

Figure 1. The correlation between the CAVI and the RRI. CAVI: cardio-ankle vascular index; RRI: renal resistive index.

Figure 2. The receiver-operating characteristic curve analysis for the detection of high RRI based on the CAVI. The maximum Youden’s index indicated that a CAVI of > 9.0 was the optimal cutoff point for the determination of high RRI (area under the curve = 0.700, P < 0.001), with a true positive rate of 59.4% and a false positive rate of 20.1%. RRI: renal resistive index; CAVI: cardio-ankle vascular index; AUC: area under the curve.

**Table 1.** Characteristics of Patients
Continuous values are mean ± SD. LDL: low-density lipoprotein; HDL: high-density lipoprotein; eGFR: estimated glomerular filtration rate; d-ROMs: derivatives of reactive oxygen metabolites; RRI: renal resistive index; CAVI: cardio-ankle vascular index; CCB: calcium channel blocker; RAS: renin-angiotensin system.
n (male/female)	245 (95/150)
Age (years)	65 ± 13
Body mass index (kg/m²)	22.6 ± 3.7
Current smoker, n (%)	63 (26)
Systolic blood pressure (mm Hg)	138 ± 10
Diastolic blood pressure (mm Hg)	87 ± 10
Pulse rate (/min)	66 ± 11
Diabetes mellitus, n (%)	99 (40)
Fasting blood glucose (mg/dL)	114 ± 25
Hemoglobin A1c (%)	6.5 ± 1.3
Dyslipidemia, n (%)	155 (63)
Total cholesterol (mg/dL)	210 ± 39
LDL-cholesterol (mg/dL)	133 ± 36
Triglyceride (mg/dL)	130 ± 67
HDL-cholesterol (mg/dL)	50 ± 13
eGFR (mL/min/1.73 m²)	65 ± 21
d-ROMs test (U. CARR)	296 ± 96
RRI	0.69 ± 0.07
CAVI	8.7 ± 1.4
Medication
CCB, n (%)	185 (76)
RAS inhibitor, n (%)	136 (56)
β-blocker, n (%)	51 (21)
Statin, n (%)	102 (42)

Table 1. Characteristics of Patients

Continuous values are mean ± SD. LDL: low-density lipoprotein; HDL: high-density lipoprotein; eGFR: estimated glomerular filtration rate; d-ROMs: derivatives of reactive oxygen metabolites; RRI: renal resistive index; CAVI: cardio-ankle vascular index; CCB: calcium channel blocker; RAS: renin-angiotensin system.

n (male/female)

245 (95/150)

Age (years)

65 ± 13

Body mass index (kg/m²)

22.6 ± 3.7

Current smoker, n (%)

63 (26)

Systolic blood pressure (mm Hg)

138 ± 10

Diastolic blood pressure (mm Hg)

87 ± 10

Pulse rate (/min)

66 ± 11

Diabetes mellitus, n (%)

99 (40)

Fasting blood glucose (mg/dL)

114 ± 25

Hemoglobin A1c (%)

6.5 ± 1.3

Dyslipidemia, n (%)

155 (63)

Total cholesterol (mg/dL)

210 ± 39

LDL-cholesterol (mg/dL)

133 ± 36

Triglyceride (mg/dL)

130 ± 67

HDL-cholesterol (mg/dL)

50 ± 13

eGFR (mL/min/1.73 m²)

65 ± 21

d-ROMs test (U. CARR)

296 ± 96

RRI

0.69 ± 0.07

CAVI

8.7 ± 1.4

Medication

CCB, n (%)

185 (76)

RAS inhibitor, n (%)

136 (56)

β-blocker, n (%)

51 (21)

Statin, n (%)

102 (42)

**Table 2.** Comparisons of Clinical Parameters of the CCB Use and RAS Inhibitor Use Patients
	CCB	RAS inhibitor	P value
Data were evaluated in patients with single-agent. Continuous values are mean ± SD. CCB: calcium channel blocker; RAS: renin-angiotensin system; LDL: low-density lipoprotein; HDL: high-density lipoprotein; eGFR: estimated glomerular filtration rate; d-ROMs: derivatives of reactive oxygen metabolites; RRI: renal resistive index; CAVI: cardio-ankle vascular index.
n (male/female)	101 (41/60)	52 (19/33)	0.629
Age (years)	66 ± 14	64 ± 13	0.342
Body mass index (kg/m²)	23.2 ± 3.6	23.2 ± 3.5	0.970
Current smoker, n (%)	28 (28)	13 (25)	0.721
Systolic blood pressure (mm Hg)	139 ± 11	139 ± 10	0.942
Diastolic blood pressure (mm Hg)	85 ± 10	88 ± 9	0.082
Pulse rate (/min)	67 ± 10	68 ± 11	0.394
Diabetes mellitus, n (%)	41 (41)	24 (46)	0.513
Fasting blood glucose (mg/dL)	115 ± 25	117 ± 26	0.717
Hemoglobin A1c (%)	6.7 ± 1.4	6.4 ± 1.2	0.096
Dyslipidemia, n (%)	66 (65)	32 (62)	0.645
Total cholesterol (mg/dL)	211 ± 40	212 ± 41	0.853
LDL-cholesterol (mg/dL)	135 ± 37	136 ± 35	0.999
Triglyceride (mg/dL)	134 ± 75	127 ± 65	0.561
HDL-cholesterol (mg/dL)	49 ± 13	52 ± 13	0.227
eGFR (mL/min/1.73 m²)	63 ± 22	68 ± 25	0.146
d-ROMs test (U. CARR)	311 ± 94	283 ± 97	0.098
RRI	0.71 ± 0.07	0.68 ± 0.04	0.006
CAVI	9.2 ± 1.5	8.4 ± 0.9	< 0.001

Table 2. Comparisons of Clinical Parameters of the CCB Use and RAS Inhibitor Use Patients

CCB

RAS inhibitor

P value

Data were evaluated in patients with single-agent. Continuous values are mean ± SD. CCB: calcium channel blocker; RAS: renin-angiotensin system; LDL: low-density lipoprotein; HDL: high-density lipoprotein; eGFR: estimated glomerular filtration rate; d-ROMs: derivatives of reactive oxygen metabolites; RRI: renal resistive index; CAVI: cardio-ankle vascular index.

n (male/female)

101 (41/60)

52 (19/33)

0.629

Age (years)

66 ± 14

64 ± 13

0.342

Body mass index (kg/m²)

23.2 ± 3.6

23.2 ± 3.5

0.970

Current smoker, n (%)

28 (28)

13 (25)

0.721

Systolic blood pressure (mm Hg)

139 ± 11

139 ± 10

0.942

Diastolic blood pressure (mm Hg)

85 ± 10

88 ± 9

0.082

Pulse rate (/min)

67 ± 10

68 ± 11

0.394

Diabetes mellitus, n (%)

41 (41)

24 (46)

0.513

Fasting blood glucose (mg/dL)

115 ± 25

117 ± 26

0.717

Hemoglobin A1c (%)

6.7 ± 1.4

6.4 ± 1.2

0.096

Dyslipidemia, n (%)

66 (65)

32 (62)

0.645

Total cholesterol (mg/dL)

211 ± 40

212 ± 41

0.853

LDL-cholesterol (mg/dL)

135 ± 37

136 ± 35

0.999

Triglyceride (mg/dL)

134 ± 75

127 ± 65

0.561

HDL-cholesterol (mg/dL)

49 ± 13

52 ± 13

0.227

eGFR (mL/min/1.73 m²)

63 ± 22

68 ± 25

0.146

d-ROMs test (U. CARR)

311 ± 94

283 ± 97

0.098

RRI

0.71 ± 0.07

0.68 ± 0.04

0.006

CAVI

9.2 ± 1.5

8.4 ± 0.9

< 0.001

**Table 3.** Relationship Between RRI, CAVI and Various Clinical Parameters
	r
r expressed correlation coefficient. P < 0.05, P < 0.01, **P < 0.001. RRI: renal resistive index; CAVI: cardio-ankle vascular index; LDL: low-density lipoprotein; HDL: high-density lipoprotein; eGFR: estimated glomerular filtration rate; d-ROMs: derivatives of reactive oxygen metabolites; CCB: calcium channel blocker; RAS: renin-angiotensin system.
Sex (female = 0, male = 1)	0.06	0.10
Age	0.19**	0.39***
Body mass index	-0.12	-0.09
Current smoker (no = 0, yes = 1)	0.05	0.17**
Systolic blood pressure	0.13*	0.04
Diastolic blood pressure	-0.19**	-0.10
Pulse rate	-0.03	0.05
Diabetes mellitus (no = 0, yes = 1)	-0.01	0.18**
Fasting blood glucose	0.06	0.19**
Hemoglobin A1c	0.03	0.22***
Dyslipidemia (no = 0, yes = 1)	0.04	-0.04
Total cholesterol	0.03	0.09
LDL-cholesterol	0.03	0.09
Triglyceride	0.02	0.07
HDL-cholesterol	0.04	-0.05
eGFR	-0.29***	-0.34***
d-ROMs test	0.30***	0.31***
CCB (no = 0, yes = 1)	0.06	0.12
RAS inhibitor (no = 0, yes = 1)	-0.24***	-0.31***
β-blocker (no = 0, yes = 1)	0.12	-0.06
Statin (no = 0, yes = 1)	-0.03	-0.15*

Table 3. Relationship Between RRI, CAVI and Various Clinical Parameters

RRI

CAVI

r expressed correlation coefficient. *P < 0.05, **P < 0.01, ***P < 0.001. RRI: renal resistive index; CAVI: cardio-ankle vascular index; LDL: low-density lipoprotein; HDL: high-density lipoprotein; eGFR: estimated glomerular filtration rate; d-ROMs: derivatives of reactive oxygen metabolites; CCB: calcium channel blocker; RAS: renin-angiotensin system.

Sex (female = 0, male = 1)

0.06

0.10

Age

0.19**

0.39***

Body mass index

-0.12

-0.09

Current smoker (no = 0, yes = 1)

0.05

0.17**

Systolic blood pressure

0.13*

0.04

Diastolic blood pressure

-0.19**

-0.10

Pulse rate

-0.03

0.05

Diabetes mellitus (no = 0, yes = 1)

-0.01

0.18**

Fasting blood glucose

0.06

0.19**

Hemoglobin A1c

0.03

0.22***

Dyslipidemia (no = 0, yes = 1)

0.04

-0.04

Total cholesterol

0.03

0.09

LDL-cholesterol

0.03

0.09

Triglyceride

0.02

0.07

HDL-cholesterol

0.04

-0.05

eGFR

-0.29***

-0.34***

d-ROMs test

0.30***

0.31***

CCB (no = 0, yes = 1)

0.06

0.12

RAS inhibitor (no = 0, yes = 1)

-0.24***

-0.31***

β-blocker (no = 0, yes = 1)

0.12

-0.06

Statin (no = 0, yes = 1)

-0.03

-0.15*

**Table 4.** Multiple Regression Analyses for RRI
Variables	β	P value
R² = 0.30, P < 0.001. RRI: renal resistive index; CAVI: cardio-ankle vascular index; d-ROMs: derivatives of reactive oxygen metabolites; RAS: renin-angiotensin system; eGFR: estimated glomerular filtration rate; β: standardized regression coefficient; R²: coefficient of determination.
CAVI	0.28	< 0.001
d-ROMs test	0.15	0.009
RAS inhibitor	-0.14	0.019
eGFR	-0.13	0.043
Systolic blood pressure	-0.11	0.108
Diastolic blood pressure	0.10	0.235
Age	0.03	0.693

Table 4. Multiple Regression Analyses for RRI

Variables

P value

R² = 0.30, P < 0.001. RRI: renal resistive index; CAVI: cardio-ankle vascular index; d-ROMs: derivatives of reactive oxygen metabolites; RAS: renin-angiotensin system; eGFR: estimated glomerular filtration rate; β: standardized regression coefficient; R²: coefficient of determination.

CAVI

0.28

< 0.001

d-ROMs test

0.15

0.009

RAS inhibitor

-0.14

0.019

eGFR

-0.13

0.043

Systolic blood pressure

-0.11

0.108

Diastolic blood pressure

0.10

0.235

Age

0.03

0.693