Increased arterial stiffness in resistant hypertension is associated with inflammatory biomarkers

Figures & data

Table I. General characteristics of normotensive, mild to moderate hypertensive and resistant hypertensive subjects.

	RHTN (n = 32)	HTN (n = 20)	NT (n = 20)	p-value
Age (years)	57.4 ± 12.9	55.1 ± 12.0	51.7 ± 5.0	0.075
Gender (F/M)	19/13	13/7	9/11	0.413
BMI (kg/m^2)	26.3 ± 2.9	26.9 ± 2.2	25.1 ± 2.3	0.103
Office SBP (mmHg)	146 ± 16^ab	131 ± 8	121 ± 14	< 0.001
Office DBP (mmHg)	86 ± 14	80 ± 7	78 ± 8	0.198
Office PP (mmHg)	61 ± 13^ab	51 ± 8	43 ± 9	< 0.001
ABPM SBP (mmHg)	131 ± 13^b	123 ± 1	–	0.014
ABPM DBP mmHg)	81 ± 12	76 ± 7	–	0.165
ABPM PP (mmHg)	51 ± 10	47 ± 8	–	0.156
PWV (m/s)	10.5 ± 2.2^ab	8.7 ± 2.1^a	7.2 ± 1.0	< 0.001

Values are expressed as mean± standard deviation. RHTN, resistant hypertension; HTN, mild to moderate hypertension; NT, normotensive subjects; F, female; M, male; BMI, body mass index; SBP, systolic blood pressure; DBP, diastolic blood pressure; PP, pulse pressure; PWV, pulse wave velocity; ABPM, ambulatory blood pressure measurement. ^avs NT; ^bvs HTN.

Table II. Biochemical parameters of normotensive, mild to moderate hypertensive and resistant hypertensive subjects.

	RHTN (n = 32)	HTN (n = 20)	NT (n = 20)	p-value
Glucose (mg/dl)	94.3 ± 11.3^a	95.0 ± 10.5^a	83.2 ± 7.9	< 0.001
Cholesterol (mg/dl)	194.8 ± 50.3	204.1 ± 36.3	207.2 ± 37.2	0.882
HDL-c (mg/dl)	49.8 ± 10.7	45.3 ± 13.6	46.8 ± 10.0	0.359
LDL-c (mg/dl)	123.9 ± 30.1	125.1 ± 28.3	120.8 ± 37.0	0.725
Triglycerides (mg/dl)	141.6 ± 77.1	162.9 ± 86.3	129.0 ± 45.2	0.437
Creatinine (mg/dl)	1.1 ± 0.3	0.9 ± 0.3	0.9 ± 0.1	0.102
Creatinine clearance (ml/min/1.73 m^2)	83.2 ± 40.9	89.8 ± 31.4	90.5 ± 15.5	0.182
Urine sodium excretion (mEq/24 hrs)	199.5 ± 79.7	183.9 ± 58.9	197.5 ± 37.8	0.467
hs-CRP (mg/l)	3.58 ± 4.26^a	3.55 ± 2.69^a	1.42 ± 2.2	< 0.001
Aldosterone (ng/dl)	10.3 ± 8.4	10.0 ± 9.2	6.6 ± 2.0	0.911
PRA (ng/ml/h)	8.1 ± 8.5	16.4 ± 25.2^a	2.9 ± 1.3	0.015
ARR (ng/dl per ng/ml/h)	2.7 ± 3.6	1.9 ± 1.8	2.7 ± 1.4	0.114

Values are expressed as mean± standard deviation. RHTN, resistant hypertension; HTN, mild to moderate hypertension; NT, normotensive subjects; LDL and HDL, low- and high-density lipoproteins, respectively; hs-CRP, high sensitivity C-reactive protein; PRA, plasma renin activity; ARR, aldosterone–renin ratio. ^avs NTN.

Figure 1. Frequency of patients according interleukin 1β (IL-1β) and interleukin 10 (IL-10) levels in normotensive, mild to moderate hypertensive and resistant hypertensive subjects (chi-square test: p = 0.0002 and p < 0.0001, respectively). NT, normotensive; HTN, mild to moderate hypertension; RHTN, resistant hypertension.

Figure 2. Comparison between tumor necrosis factor- α (TNF-α) and interleukin 6 (IL-6) levels in normotensive, mild to moderate hypertensive and resistant hypertensive subjects. (mean (95% CI). NT, normotensive; HTN, mild to moderate hypertension; RHTN, resistant hypertension). p = 0.0018. *vs NT.

Figure 3. Arterial stiffness (pulse wave velocity, PWV) in normotensive (NT), mild to moderate hypertensive (HTN) and resistant hypertensive subjects (RHTN). p < 0.0001 *vs NT; ^#vs HTN.

Table III. Multivariate linear regression analysis for the associations between inflammatory biomarkers [interleukin 1β (IL-1β), interleukin 10 (IL-10), tumor necrosis factor-α (TNF-α) and high-sensitivity C-reactive protein (hs-CRP)], and arterial stiffness of normotensive, mild to moderate hypertensive and resistant hypertensive subjects.

	β	SE	p-value
IL-1β (pg/ml)	0.077	0.022	< 0.001*
IL-10 (pg/ml)	0.007	0.020	0.728
TNF-α (pg/ml)	0.001	0.003	0.657
hs-CRP (mg/l)	0.034	0.026	0.194
Glucose (mg/dl)	0.0005	0.0004	0.192
Age (years)	0.003	0.0008	0.001*
Office SBP (mmHg)	0.001	0.0005	0.041*

R = 0.7; R² = 0.50; adjusted R² = 0.46; β, beta coefficient; SE, standard error; SBP, systolic blood pressure, n = 72.

*p 0.05.