Stiffness index derived from digital volume pulse as a marker of target organ damage in untreated hypertension

Figures & data

Figure 1. Digital volume pulse (DVP) was recorded from a photoplethysmography. ΔT represented transitional time from first peak to second peak. Stiffness index derived from DVP (SI_DVP) was calculated from body height divided by Δt.

Table I. Correlations between clinical characteristics and aortic stiffness.

Characteristics	SIDVP	SI	DI
Age	r = 0.162, p = 0.071	r = 0.450, p<0.001	r = −0.514, p<0.001
Duration of hypertension	r = 0.163, p = 0.081	r = 0.357, p<0.001	r = −0.291, p = 0.002
Systolic blood pressure	r = 0.089, p = 0.324	r = 0.171, p = 0.058	r = −0.334, p<0.001
Diastolic blood pressure	r = 0.202, p = 0.024	r = −0.219, p = 0.015	r = 0.066, p = 0.468
Cholesterol	r = 0.044, p = 0.672	r = 0.195, p = 0.059	r = −0.249, p = 0.015
Triglyceride	r = 0.275, p = 0.008	r = 0.136, p = 0.196	r = −0.074, p = 0.484

SI_DVP, stiffness index derived from digital volume pulse; SI, stiffness index derived from M‐mode echocardiography; DI, distensibility.

Table II. Risk factors and aortic stiffness.

	SIDVP (m/s)	SI	DI (10^−6 cm^2/dyne)
Sex
Man (57)	9.03±2.01	9.58±6.30	1.99±1.10
Woman (67)	8.68±2.38	10.22±9.99	1.63±1.08
Diabetes mellitus
Present (12)	8.78±1.35	15.88±12.54	1.39±0.94
Absent (112)	8.84±2.30	11.08±8.08	1.84±1.11
Smoking
Present (20)	9.26±1.75	12.02±8.41	1.68±1.10
Absent (104)	8.76±2.30	11.45±8.75	1.82±1.10
Hyperlipidemia
Present (68)	9.07±2.40	12.45±8.51	1.64±1.09
Absent (56)	8.57±2.02	10.73±9.04	1.97±1.12

Data was expressed as mean±SD.

SI_DVP, stiffness index derived from digital volume pulse; SI, stiffness index derived from M‐mode echocardiography; DI, distensibility.

Table III. Correlation between aortic stiffness and measurements of end organ damage.

	SIDVP	SI	DI
BUN	r = 0.230, p = 0.023	r = 0.168, p = 0.100	r = −0.231, p = 0.023
Creatinine	r = 0.049, p = 0.628	r = 0.279, p = 0.005	r = −0.174, p = 0.083
LVMI	r = 0.177, p = 0.050	r = 0.117, p = 0.198	r = −0.239, p = 0.008
E/A	r = −0.031, p = 0.734	r = 0.279, p = 0.002	r = −0.102, p = 0.261

BUN, blood urea nitrogen; LVMI, left ventricular mass index; E/A, peak atrial velocity and early filling to atrial velocity ratio.

Table IV. Comparison between patients with or without vascular diseases.

	Vascular diseases (+) (n = 29)	Vascular diseases (−) (n = 95)	p‐value
Age (years)	57.2±13.1	54.9±13.1	0.403
Duration of hypertension (years)	4.2±3.5	3.5±4.5	0.446
Systolic blood pressure (mmHg)	189±26	180±27	0.133
Diastolic blood pressure (mmHg)	113±16	107±24	0.222
Cholesterol (mg/dl)	213.7±38.6	203.9±37.8	0.286
Triglyceride (mg/dl)	140.0±90.9	141.1±73.3	0.955
Fasting glucose (mg/dl)	99.5±19.7	104.2±24.6	0.478
LVMI (g/m^2)	114.4±40.6	96.8±35.1	0.026
E/A	0.91±0.34	1.79±1.49	0.530
SIDVP (m/s)	10.12±2.97	8.45±1.78	<0.001
SI	13.76±7.63	10.87±8.88	0.116
DI (10^−6 cm^2/dyne)	1.34±0.88	1.93±1.12	0.010

Data was expressed as mean±SD.

LVMI, left ventricular mass index; E/A, peak atrial velocity and early filling to atrial velocity ratio; SI_DVP, stiffness index derived from digital volume pulse; SI, stiffness index derived from M‐mode echocardiography; DI, distensibility.

Table V. Multiple logistic analysis for association of vascular diseases.

	Odd ratio (95% CI)	p value
SIDVP	1.389 (1.062–1.817)	0.016
SI	0.977 (0.887–1.076)	0.639
DI	0.494 (0.201–1.216)	0.125
Age	1.017 (0.967–1.070)	0.506
Duration of hypertension	1.027 (0.891–1.184)	0.712
Systolic blood pressure	0.991 (0.967–1.017)	0.498
Diastolic blood pressure	1.019 (0.984–1.054)	0.291

SI_DVP, stiffness index derived from digital volume pulse; SI, stiffness index derived from M‐mode echocardiography; DI, distensibility.