J Clin Med Res

Journal of Clinical Medicine Research, ISSN 1918-3003 print, 1918-3011 online, Open Access

Article copyright, the authors; Journal compilation copyright, J Clin Med Res and Elmer Press Inc

Journal website http://www.jocmr.org

Original Article

Volume 11, Number 8, August 2019, pages 593-599

Relationships Between the Cardio-Ankle Vascular Index and Pulsatility Index of the Common Carotid Artery in Patients With Cardiovascular Risk Factors

Figure 1. The correlation between the CAVI and the PI of the CCA. CAVI: cardio-ankle vascular index; PI: pulsatility index; CCA: common carotid artery.

Figure 2. The receiver-operating characteristic curve analysis for the detection of high PI of the CCA based on the CAVI. The maximum Youden index indicated that a CAVI of > 9.1 was the optimal cut-off point to determine high PI (AUC = 0.750, P < 0.001) with a true positive rate of 56.5% and a false positive rate of 82.6%. PI: pulsatility index; CCA: common carotid artery; CAVI: cardio-ankle vascular index; AUC: area under the curve.

**Table 1.** Patient Characteristics
Continuous values are mean ± SD. HbA1c: hemoglobinA1c; AF: autofluorescence; AU: arbitrary units; LDL: low-density lipoprotein; HDL: high-density lipoprotein; eGFR: estimated glomerular filtration rate; hs-CRP: high-sensitivity C-reactive protein; PI: pulsatility index; CCA: common carotid artery; IMT: intima-media thickness; CAVI: cardio-ankle vascular index; RAS: renin-angiotensin system.
n (male/female)	405 (152/253)
Age (years)	64 ± 9
Body mass index (kg/m²)	22.7 ± 3.7
Current smoker, n (%)	104 (26)
Hypertension, n (%)	286 (71)
Systolic blood pressure (mm Hg)	139 ± 11
Diastolic blood pressure (mm Hg)	86 ± 9
Diabetes mellitus, n (%)	169 (42)
Fasting blood glucose (mg/dL)	114 ± 24
HbA1c (%)	6.2 ± 1.1
Skin AF (AU)	2.5 ± 0.6
Dyslipidemia, n (%)	251 (62)
Total cholesterol (mg/dL)	212 ± 41
LDL-cholesterol (mg/dL)	134 ± 37
Triglyceride (mg/dL)	129 ± 65
HDL-cholesterol (mg/dL)	51 ± 14
eGFR (mL/min/1.73 m² )	62 ± 21
Log-hs-CRP (mg/dL)	-1.2 ± 0.7
PI of CCA	1.59 ± 0.26
Max-IMT (mm)	1.36 ± 0.49
CAVI	8.7 ± 1.3
Medication
RAS inhibitor, n (%)	222 (55)
Statin, n (%)	167 (41)
Anti-diabetic drugs, n (%)	133 (33)

Table 1. Patient Characteristics

Continuous values are mean ± SD. HbA1c: hemoglobinA1c; AF: autofluorescence; AU: arbitrary units; LDL: low-density lipoprotein; HDL: high-density lipoprotein; eGFR: estimated glomerular filtration rate; hs-CRP: high-sensitivity C-reactive protein; PI: pulsatility index; CCA: common carotid artery; IMT: intima-media thickness; CAVI: cardio-ankle vascular index; RAS: renin-angiotensin system.

n (male/female)

405 (152/253)

Age (years)

64 ± 9

Body mass index (kg/m²)

22.7 ± 3.7

Current smoker, n (%)

104 (26)

Hypertension, n (%)

286 (71)

Systolic blood pressure (mm Hg)

139 ± 11

Diastolic blood pressure (mm Hg)

86 ± 9

Diabetes mellitus, n (%)

169 (42)

Fasting blood glucose (mg/dL)

114 ± 24

HbA1c (%)

6.2 ± 1.1

Skin AF (AU)

2.5 ± 0.6

Dyslipidemia, n (%)

251 (62)

Total cholesterol (mg/dL)

212 ± 41

LDL-cholesterol (mg/dL)

134 ± 37

Triglyceride (mg/dL)

129 ± 65

HDL-cholesterol (mg/dL)

51 ± 14

eGFR (mL/min/1.73 m² )

62 ± 21

Log-hs-CRP (mg/dL)

-1.2 ± 0.7

PI of CCA

1.59 ± 0.26

Max-IMT (mm)

1.36 ± 0.49

CAVI

8.7 ± 1.3

Medication

RAS inhibitor, n (%)

222 (55)

Statin, n (%)

167 (41)

Anti-diabetic drugs, n (%)

133 (33)

**Table 2.** Relationship Between the PI of the CCA, the CAVI and Various Clinical Parameters
	r
r expressed correlation coefficient. P < 0.05, P < 0.01, **P < 0.001. PI: pulsatility index; CCA: common carotid artery; CAVI: cardio-ankle vascular index; HbA1c: hemoglobinA1c; AF: autofluorescence; LDL: low-density lipoprotein; HDL: high-density lipoprotein; eGFR: estimated glomerular filtration rate; hs-CRP: high-sensitivity C-reactive protein; IMT: intima-media thickness; RAS: renin-angiotensin system.
Sex (female = 0, male = 1)	-0.01	0.07
Age	0.28***	0.32***
Body mass index	-0.01	-0.03
Current smoker (no = 0, yes = 1)	0.13*	0.13**
Hypertension (no = 0, yes = 1)	0.10*	0.12*
Systolic blood pressure	0.17**	0.11*
Diastolic blood pressure	-0.06	-0.08
Diabetes mellitus (no = 0, yes = 1)	0.31***	0.14**
Fasting blood glucose	0.09	0.13**
HbA1c	0.16**	0.19***
Skin AF	0.38***	0.44***
Dyslipidemia (no = 0, yes = 1)	-0.07	-0.04
Total cholesterol	-0.02	-0.06
LDL-cholesterol	-0.03	-0.06
Triglyceride	0.05	0.07
HDL-cholesterol	-0.03	-0.05
eGFR	-0.26***	-0.17***
Log-hs-CRP	0.35***	0.33***
Max-IMT	0.30***	0.34***
RAS inhibitor (no = 0, yes = 1)	-0.11*	-0.12*
Statin (no = 0, yes = 1)	-0.10*	-0.10*
Anti-diabetic drugs (no = 0, yes = 1)	0.21***	0.09

Table 2. Relationship Between the PI of the CCA, the CAVI and Various Clinical Parameters

PI of CCA

CAVI

r expressed correlation coefficient. *P < 0.05, **P < 0.01, ***P < 0.001. PI: pulsatility index; CCA: common carotid artery; CAVI: cardio-ankle vascular index; HbA1c: hemoglobinA1c; AF: autofluorescence; LDL: low-density lipoprotein; HDL: high-density lipoprotein; eGFR: estimated glomerular filtration rate; hs-CRP: high-sensitivity C-reactive protein; IMT: intima-media thickness; RAS: renin-angiotensin system.

Sex (female = 0, male = 1)

-0.01

0.07

Age

0.28***

0.32***

Body mass index

-0.01

-0.03

Current smoker (no = 0, yes = 1)

0.13*

0.13**

Hypertension (no = 0, yes = 1)

0.10*

0.12*

Systolic blood pressure

0.17**

0.11*

Diastolic blood pressure

-0.06

-0.08

Diabetes mellitus (no = 0, yes = 1)

0.31***

0.14**

Fasting blood glucose

0.09

0.13**

HbA1c

0.16**

0.19***

Skin AF

0.38***

0.44***

Dyslipidemia (no = 0, yes = 1)

-0.07

-0.04

Total cholesterol

-0.02

-0.06

LDL-cholesterol

-0.03

-0.06

Triglyceride

0.05

0.07

HDL-cholesterol

-0.03

-0.05

eGFR

-0.26***

-0.17***

Log-hs-CRP

0.35***

0.33***

Max-IMT

0.30***

0.34***

RAS inhibitor (no = 0, yes = 1)

-0.11*

-0.12*

Statin (no = 0, yes = 1)

-0.10*

Anti-diabetic drugs (no = 0, yes = 1)

0.21***

0.09

**Table 3.** Multiple Regression Analyses
Explanatory factor	β	P value
(A) Subordinate factor is PI of CCA; R² = 0.37; P < 0.001. (B) Subordinate factor is CAVI; R² = 0.36; P < 0.001. AF: autofluorescence; hs-CRP: high-sensitivity C-reactive protein; CAVI: cardio-ankle vascular index; IMT: intima-media thickness; PI: pulsatility index; CCA: common carotid artery; β: standardized regression coefficient; R²: coefficient of determination.
(A) Skin AF	0.25	< 0.001
Log-hs-CRP	0.20	< 0.001
CAVI	0.19	< 0.001
Diabetes mellitus	0.15	0.003
Max-IMT	0.14	0.009
(B) Skin AF	0.27	< 0.001
Max-IMT	0.19	< 0.001
PI of CCA	0.17	0.002
Log-hs-CRP	0.16	0.003
Age	0.15	0.007

Table 3. Multiple Regression Analyses

Explanatory factor

P value

(A) Subordinate factor is PI of CCA; R² = 0.37; P < 0.001. (B) Subordinate factor is CAVI; R² = 0.36; P < 0.001. AF: autofluorescence; hs-CRP: high-sensitivity C-reactive protein; CAVI: cardio-ankle vascular index; IMT: intima-media thickness; PI: pulsatility index; CCA: common carotid artery; β: standardized regression coefficient; R²: coefficient of determination.

(A) Skin AF

0.25

< 0.001

Log-hs-CRP

0.20

< 0.001

CAVI

0.19

< 0.001

Diabetes mellitus

0.15

0.003

Max-IMT

0.14

0.009

(B) Skin AF

0.27

< 0.001

Max-IMT

0.19

< 0.001

PI of CCA

0.17

0.002

Log-hs-CRP

0.16

0.003

Age

0.15

0.007