Cellular adhesion molecules and blood pressure: interaction with sex in a multi-ethnic population

Synergism of cell adhesion regulatory genes and instant air pollutants on blood pressure elevation

Accumulating evidence suggests that an instant exposure to particulate matter (PM) may elevate blood pressure (BP), where cell-adhesion regulatory genes may be involved in the interplay. However, few studies to date critically examined their interaction, and it remained unclear whether these genes modified the association. To assess the association between instant PM exposure and BP, and to examine whether single-nucleotide polymorphisms (SNPs) mapped in four cell adhesion regulatory genes modify the relationship, a cross-sectional study was performed, based on the baseline of an ongoing family-based cohort in Beijing, China. A total of 4418 persons from 2089 families in Northern China were included in the analysis. Four tagged SNPs in cell adhesion regulatory genes were selected among ZFHX3, CXCL12, RASGRP1 and MIR146A. A generalized additive model (GAM) with a Gaussian link was adopted to estimate the change in blood pressure after instant PM_2.5 or PM₁₀ exposure. A cross-product term of PM_2.5/PM₁₀ and genotype was incorporated into the GAM model to test for interaction. The study observed that an instant exposure to either PM_2.5 or PM₁₀ was found to be associated with elevated systolic blood pressure (SBP). On average, a 10 μg/m³ increase in instant exposure to PM_2.5 and PM₁₀ concentration corresponded to 0.140% (95% CI: 0.014%-0.265%, P = 0.029) and 0.173% (95% CI: 0.080%-0.266%, P < 0.001) higher SBP. However, diastolic blood pressure (DBP) was not elevated as the PM_2.5 or PM₁₀ concentration increased (P > 0.05). A synergetic interaction on SBP was observed between SNPs in four cell adhesion regulatory genes (rs2910164 in MIR146A, rs2297630 in CXCL12, rs7403531 in RASGRP1, and rs7193343 in ZFHX3) and instant PM_2.5 exposure (P_{for interaction} <0.05). Briefly, as carriers of risk alleles in each of these four genes increased, an enhanced association was found between instant PM_2.5 exposure and SBP.

Selective inhibition of histone deacetylase 8 improves vascular hypertrophy, relaxation, and inflammation in angiotensin II hypertensive mice

Background

The dysregulation of histone deacetylase (HDAC) protein expression or its enzyme activity is implicated in a variety of diseases. Cardiac HDAC6 and HDAC8 enzyme activity induced by deoxycorticosterone acetate (DOCA) hypertension was attenuated by sodium valproate, a pan-HDAC inhibitor. However, the HDAC6-selective inhibitor, tubastatin A, did not attenuate angiotensin II-induced hypertension. The purpose of this study was to investigate whether PCI34051, an HDAC8-selective inhibitor, can modulate angiotensin II-induced hypertension and its regulatory mechanism.

Methods

An angiotensin II-regulated mouse model was used in this study. Animals received vehicle or PCI34051 (3 mg·kg - ¹·day- ¹) via intraperitoneal injection. Systolic blood pressure was measured by the tail-cuff method. Blood vessel thickness was measured following hematoxylin and eosin staining, VCAM-1 immunohistochemistry was performed in the aortas, and mRNA expression of renin-angiotensin system components, inflammation markers, and NADPH oxidase (Nox) was determined by RT-PCR. The effect of PCI34051 on vasorelaxation was studied in rat aortic rings, and its effect on nitric oxide (NO) production was determined using DAF-FM DA, a fluorescent dye, in human umbilical vascular endothelial cells (HUVECs).

Results

PCI34051 administration reduced systolic blood pressure via downregulation of angiotensin II receptor type 1 (AT1) mRNA expression. PCI34051 treatment attenuated vascular hypertrophy by decreasing E2F3 and GATA6 mRNA expression. Vascular relaxation after PCI34051 treatment was more dependent on vascular endothelial cells and it was blocked by an NO synthase (NOS) inhibitor. In addition, NO production increased in HUVECs after PCI34051 treatment; this was decreased by the NOS inhibitor. The expression of inflammatory molecules and adhesion molecules VCAM-1 and ICAM-1 decreased in the aortas of angiotensin II-infused mice after PCI34051 administration. However, PCI34051 did not affect Nox or its regulatory subunits.

Conclusions

PCI34051 lowered high blood pressure through modulation of arterial remodeling, vasoconstriction, and inflammation in an angiotensin II-induced hypertension model. We suggest that HDAC8 could be a potential therapeutic target for hypertension.

Intercellular adhesion molecule-1 (ICAM-1) associates with 24-hour ambulatory blood pressure variability in type 2 diabetes and controls

BACKGROUND AND AIM

Endothelial dysfunction is a common feature in hypertension and type 2 diabetes. Whether blood pressure (BP) variability is influencing serum intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) remains to be clarified. We aimed to assess the association between the circulating adhesion molecules and ambulatory blood pressure variability in patients with type 2 diabetes and controls.

PATIENTS AND METHODS

The study included data from type 2 diabetes with controlled BP (n = 55), type 2 diabetes with uncontrolled BP (n = 55) and control subjects (n = 28). ICAM-1 and VCAM-1 were measured with specific enzyme-linked immunosorbent assay method. BP variability was assessed using standard deviation of mean systolic and diastolic BP evaluated during 24-hour ambulatory BP monitoring.

RESULTS

The uncontrolled BP type 2 diabetes group had significantly higher serum ICAM-1 and VCAM-1 levels compared to controlled BP type 2 diabetes and control groups. In linear regression analysis, after adjustment, higher ICAM-1 was consistently associated with higher daytime and 24-hour diastolic BP variability, and daytime systolic BP variability in the study population. VCAM-1 was associated only with daytime systolic BP variability.

CONCLUSIONS

Our study evaluating the association of serum ICAM-1 and VCAM-1 with 24-hour ambulatory BP variability in patients with type 2 diabetes and controls might offer better understanding of the mechanisms generating endothelial dysfunction. Elevated 24-hour ambulatory BP variability might induce endothelial activation by increasing circulating adhesion molecules levels.

Biomarkers of inflammation and endothelial dysfunction as predictors of pulse pressure and incident hypertension in type 1 diabetes: a 20 year life-course study in an inception cohort

AIMS/HYPOTHESIS

Vascular inflammation and endothelial dysfunction are thought to contribute to arterial stiffening and hypertension. This study aims to test this hypothesis with longitudinal data in the context of type 1 diabetes.

METHODS

We investigated, in an inception cohort of 277 individuals with type 1 diabetes, the course, tracking and temporal inter-relationships of BP, specifically pulse pressure (a marker of arterial stiffening) and hypertension, and the following biomarkers of systemic and vascular inflammation/endothelial dysfunction: C-reactive protein (CRP), soluble intracellular adhesion molecule-1 (sICAM-1), soluble vascular cellular adhesion molecule-1 (sVCAM-1) and soluble E-selectin (sE-selectin). These biomarkers and other risk factors were measured at baseline and repeatedly up to 20 years after the onset of type 1 diabetes. Data were analysed with generalised estimating equations including adjustments for age, sex, smoking status, BMI, HbA_1c, serum creatinine, total cholesterol, urinary AER, insulin treatment dose and mean arterial pressure.

RESULTS

Increases were noted in all biomarkers except sE-selectin, which decreased over time. Levels differed from baseline at 2-4 years and preceded the increase in pulse pressure, which occurred at 8-10 years after the onset of type 1 diabetes. Higher levels of sICAM-1 and sVCAM-1, but not CRP or sE-selectin, at baseline and throughout the 20 year follow-up, were significantly associated with higher (changes in) pulse pressure at subsequent time points. Higher levels of sVCAM-1 at baseline and during follow-up were also significantly associated with the prevalence (OR 3.60 [95% CI 1.36, 9.53] and OR 2.28 [1.03, 5.25], respectively) and incidence (OR 2.89 [1.08, 7.75] and OR 3.06 [1.01, 9.26], respectively) of hypertension. We also investigated the longitudinal associations between BP or hypertension as determinants of subsequent (changes in) levels of CRP, sICAM-1, sVCAM-1 and sE-selectin, but did not find evidence to support a reverse causality hypothesis.

CONCLUSIONS/INTERPRETATION

These findings support the involvement of vascular endothelial dysfunction and inflammation in the development of premature arterial stiffening and hypertension in type 1 diabetes.

Expression of Heat Shock Protein 70 Gene and Its Correlation with Inflammatory Markers in Essential Hypertension

OBJECTIVES

Hypertension is characterized by systemic high blood pressure and is the most common and important risk factor for the development of cardiovascular diseases. Studies have shown that the circulating levels of certain inflammatory markers such as tumor necrosis factor-alpha (TNF-alpha), interlukin-6 (IL-6), c-reactive protein (CRP), and tumor suppressor protein-53 (p53) are upregulated and are independently associated with essential hypertension. However, mechanism of increase in the levels of HSP70 protein is not clear. No such studies are reported in the blood circulation of patients with essential hypertension. In the present study, we investigated the expression of circulating HSP70 at mRNA and protein levels and its relationship with other inflammatory markers in patients with essential hypertension.

MATERIALS AND METHODS

We recruited 132 patients with essential hypertension and 132 normal controls from similar socio-economic-geographical background. The expression of HSP70 at mRNA levels was determined by Real Time PCR and at protein levels by indirect Elisa and Western Blot techniques.

RESULTS

We found a significantly higher expression of HSP70 gene expression (approximately 6.45 fold, P < 0.0001) in hypertensive patients as compared to healthy controls. A significant difference (P < 0.0001) in the protein expression of HSP70 was also observed in plasma of patients as compared to that of controls.

CONCLUSION

Higher expression of HSP70 is positively correlated with inflammatory markers in patients with essential hypertension and this correlation could play an important role in essential hypertension.

Plasma sE-selectin level is positively correlated with neutrophil count and diastolic blood pressure in Japanese men

Increased levels of circulating soluble type of E-selectin (sE-selectin), neutrophil counts and blood pressure are associated with the development of cardiovascular diseases (CVD). In this study, we conducted a cross-sectional study of men who participated in health check-ups, and selected those who were not diagnosed with or being treated for metabolic diseases such as diabetes, hypertension and lipid abnormality according to the health check-ups. We measured their basic clinical parameters including blood pressure and neutrophil count, plasma sE-selectin concentration and lifestyle factors, and assessed their interrelations by multivariate linear regression (MLR) analysis. A total of 351 subjects aged 47.5±8.41 (range, 30-64) y were recruited. Significantly correlated with sE-selectin concentration were neutrophil count, diastolic blood pressure (DBP), and systolic blood pressure (SBP) (Pearson's correlation coefficient, 0.194, 0.220 and 0.175, respectively). MLR analysis showed that sE-selectin concentration was independently positively related with DBP and neutrophil count, whereas neutrophil count was positively associated with sE-selectin concentration but not DBP. DBP, but not SBP, was independently positively correlated with sE-selectin concentration but not neutrophil count. These results indicate that circulating sE-selectin concentration may be a biomarker for indicating subsequent development of metabolic diseases, in particular CVD, from a healthy state.

Cyclophilin-A: a novel biomarker for untreated male essential hypertension

Vascular cytokines, total nitrite, and cyclophilin-A (CyP-A) may be related to the pathogenesis of untreated hypertension. Forty males with normotensive and untreated essential hypertension were recruited in this cytokines survey. Body mass index (BMI), hyperlipidemia, and plasma CyP-A were increased in the hypertensive group (p < 0.05). However, only BMI (p = 0.022) and plasma CyP-A (p = 0.020) were found to be significant contributors to hypertension by multiple regression analysis. CyP-A was also positively correlated with systolic blood pressure (p = 0.029) and diastolic blood pressure (p = 0.047). These findings indicated that plasma CyP-A is a critical molecular biomarker in the early pathogenesis of essential hypertension.

Selectins and Associated Adhesion Proteins in Inflammatory disorders

Inflammation is defined as the normal response of living tissue to injury or infection. It is important to emphasize two components of this definition. First, that inflammation is a normal response and, as such, is expected to occur when tissue is damaged. Infact, if injured tissue does not exhibit signs of inflammation this would be considered abnormal and wounds and infections would never heal without inflammation. Secondly, inflammation occurs in living tissue, hence there is need for an adequate blood supply to the tissues in order to exhibit an inflammatory response. The inflammatory response may be triggered by mechanical injury, chemical toxins, and invasion by microorganisms, and hypersensitivity reactions. Three major events occur during the inflammatory response: the blood supply to the affected area is increased substantially, capillary permeability is increased, and leucocytes migrate from the capillary vessels into the surrounding interstitial spaces to the site of inflammation or injury. The inflammatory response represents a complex biological and biochemical process involving cells of the immune system and a plethora of biological mediators. Cell-to-cell communication molecules such as cytokines play an extremely important role in mediating the process of inflammation. Inflammation and platelet activation are critical phenomena in the setting of acute coronary syndromes. An extensive exposition of this complex phenomenon is beyond the scope of this article (Rankin 2004).

Circulating inflammatory and endothelial markers and risk of hypertension in white and black postmenopausal women

BACKGROUND

Systemic inflammation and endothelial activation are implicated in the development of hypertension. However, epidemiologic studies have yet to compare multiple corresponding biomarkers in relation to risk of hypertension, particularly in multiethnic populations.

METHODS

We identified 800 individuals with incident hypertension and 800 matched controls, each group with equal numbers of white and black women, in a nested case-control study within the Women's Health Initiative Observational Study. We measured markers of inflammation [high-sensitivity C-reactive protein (hsCRP), interleukin (IL)-6, IL-1β, tumor necrosis factor receptor 2 (TNF-r2)] and endothelial activation [soluble intercellular adhesion molecule-1 (sICAM-1)] in baseline blood samples.

RESULTS

Before adjustment for measures of adiposity, higher hsCRP and IL-6 concentrations were associated with increased risk of hypertension in both white and black women, higher TNF-r2 was associated with increased risk of hypertension in black women only, and IL-1β and sICAM-1 were not associated with risk of hypertension. All the positive associations were attenuated after adjustment for body mass index. The resulting multivariable-adjusted relative risks (95% CI) of hypertension comparing the highest vs lowest quartile were 1.52 (0.94-2.48) and 1.23 (0.76-1.97) for hsCRP and IL-6 in white women and 1.30 (0.81-2.07), 1.58 (0.96-2.59), and 1.49 (0.94-2.36) for hsCRP, IL-6, and TNF-r2 in black women. The results after adjustment for waist circumference were similar.

CONCLUSIONS

After adjustment for measures of adiposity, there was no significant association of hsCRP, IL-6, IL-1β, TNF-r2, or sICAM-1 with incident hypertension in either white or black women. The interrelationships between inflammation and adiposity in development of hypertension need further investigation.

Association of elevated inflammatory and endothelial biomarkers with prehypertension among Mongolians in China

Chronic inflammation and endothelial dysfunction may be associated with hypertension and cardiovascular disease. We examined associations between inflammatory and endothelial dysfunction biomarkers and the risk of prehypertension among Mongolians. A cross-sectional study was conducted among 2589 Mongolians aged 20 years and older in Inner Mongolia, China. Three blood pressure measurements, body weight, height and lifestyle factors were obtained for all participants. Overnight fasting blood samples were obtained to measure the biomarkers, including C-reactive protein (CRP), soluble intercellular adhesion molecule-1 (sICAM-1), soluble E-selectin (sE-selectin) and angiotensin II. The average levels of CRP (7.43 vs. 5.86), sICAM-1 (339.38 vs. 328.05), sE-selectin (19.11 vs. 18.32) and angiotensin II (52.00 vs. 47.00) were all significantly higher in hypertensives than that in prehypertensives (all P<0.05); prehypertensives had higher levels of CRP (5.86 vs. 4.85) and sICAM-1 (328.05 vs. 314.14) compared with normotensives (both P<0.05). Hypertension (odds ratio (OR): 1.50, 95% confidence interval (CI): 1.07, 2.11) and prehypertension (OR: 1.38, 95% CI: 1.02, 1.85) were positively and significantly associated with elevated CRP adjusted for multivariable. Hypertension (OR: 1.56, 95% CI: 1.18, 2.06) and prehypertension (OR: 1.32, 95% CI: 1.02, 1.71) were also positively and significantly associated with higher sICAM-1 adjusted for age and gender. Elevated CRP and sICAM-1 were associated with prehypertension among Mongolian population. This study suggests that inflammation and endothelial dysfunction may have a role in the development of hypertension.

Circulating levels of cell adhesion molecules in hypertension

Hypertension causes complications such as coronary atherosclerosis and thrombosis wherein inflammatory factors play significant role. In the present study inflammatory molecules such as cell adhesion molecules (CAMs); endothelial (E)-selectin, platelet (P)-selectin, intercellular CAM-1 (ICAM-1), vascular CAM-1 (VCAM-1) and platelet endothelial CAM-1 (PECAM-1) were analysed in subjects newly diagnosed with hypertension with no secondary cause against normotensive healthy individuals. In each group 57 subjects were recruited and soluble (s) levels of CAMs were analysed by ELISA. As compared to controls median of sE-selectin (49.2%, P=0.001), sP-selectin (54.3%, P=0.001), and sICAM-1 (18.9%, P=0.012) were significantly elevated in hypertensive subjects. Significant negative correlation was observed of sP-selectin (spearman rank correlation coefficient (rs) =-0.345, p=0.027) and sPECAM-1 (rs =-0.446, p=0.003) with age in hypertension group. Hypertension may increase expression of certain CAMs while younger hypertensives in addition are also at increased risk of atherothrombosis.

Chronic discrimination predicts higher circulating levels of E-selectin in a national sample: the MIDUS study

Chronic discrimination in both minority and non-minority populations is linked to adverse health outcomes, including increased risk of cardiovascular disease and increased mortality, but the biological processes through which discrimination affects health are unclear. The current study tested the hypothesis that discrimination in a sample of Caucasians would predict elevated serum levels of E-selectin, an indication of endothelial dysfunction which itself is associated with atherosclerosis and cardiovascular disease risk. Participants (N=804) in the biomarker sample from the Survey of Midlife in the United States (MIDUS) provided information about experiences of both major and everyday discrimination at two times separated by a 9-10 year interval. The discrimination measures were designed to assess perceived unfair treatment (e.g. being fired unfairly) independently of the perceived reasons for the unfair treatment (e.g. race, gender). Serum E-selectin was measured at the second wave of data collection. Women reported significantly more instances of major (P<0.05) and everyday P<0.001) discrimination than men. Analyses of Covariance (ANCOVA) showed that both greater lifetime exposure to major discrimination (P<0.05) and chronic exposure to everyday discrimination (P<0.05) predicted higher circulating levels of E-selectin, but only in men. These associations remained statistically significant after adjustments for potential confounding variables, including age, race, socioeconomic status, health status, and health behavior. These results highlight a potential biological mechanism by which exposure to unfair treatment may be related to health, particularly cardiovascular function. Moreover, they add to a growing literature suggesting that unfair treatment in general may predict adverse health outcomes.

Elevation of serum soluble E- and P-selectin in patients with hypertension is reversed by benidipine, a long-acting calcium channel blocker

Hypertension is a major risk factor for atherosclerotic cardiovascular disease. Selectins, cell-surface adhesion molecules involved in leukocyte rolling and attachment to the vascular endothelium, play a role in the initiation of atherosclerosis. We investigated whether or not serum levels of soluble adhesion molecules are elevated in patients with essential hypertension (EH) and examined whether antihypertensive therapy lowers such levels. Twenty-one patients who had untreated mild to moderate EH without diabetes mellitus, hyperlipidemia, or obesity were recruited at a clinic for hypertensive patients. Blood pressure was measured, and the serum levels of soluble E-selectin, P-selectin, L-selectin, intercellular adhesion molecule 1 (ICAM-1), and vascular-cell adhesion molecule 1 (VCAM-1) were determined by enzyme-linked immunosorbent assays before and after 12, 24, and 53 weeks of antihypertensive treatment with benidipine, a long-acting calcium channel blocker, given at a dose of 6 mg/day for 53 weeks. As a control, 21 age- and sex-matched patients without hypertension were studied. Serum E- and P-selectin levels were significantly higher in the subjects with EH than in the controls (p < 0.01). There were no differences in serum levels of soluble L-selectin, VCAM-1, or ICAM-1 levels between the patients with EH and the controls. Treatment with benidipine decreased the elevated blood pressure over a 53-week study period (mean blood pressure: 119.8 +/- 6.5 mmHg at baseline, 101.0 +/- 5.9 mmHg at 12 weeks, 98.6 +/- 7.3 mmHg at 24 weeks, and 93.9 +/- 5.5 mmHg at 53 weeks). Serum levels of soluble E- and P-selectin decreased after the initiation of benidipine treatment and correlated with diastolic blood pressure. Serum levels of soluble L-selectin, VCAM-1, and ICAM-1 did not change significantly during the period of benidipine treatment. Benidipine treatment reduced the content of P-selectin in the platelets from patients with EH, as determined by Western blot analysis. In conclusion, decreased blood pressure may reduce the rate of progression of atherosclerosis by affecting the expression of E- and P-selectin in the endothelium, the platelets, or both. Benidipine may be protective against vascular damage in people with hypertension, not only by lowering blood pressure, but also by inhibiting the expression of selectins.

Circulating markers of endothelial function in cardiovascular disease

Endothelial dysfunction is a key event in cardiovascular disease. Measurement of endothelial dysfunction in vivo presents a major challenge, but has important implications since it may identify the clinical need for therapeutic intervention, specifically in primary prevention. Several biological markers have been used as indicators of endothelial dysfunction. The soluble adhesion molecules sICAM-1 and sVCAM-1 lack specificity and are increased in inflammatory processes. Both markers are increased in coronary artery disease. sICAM-1 level predicts the risk for cardiovascular disease or diabetes mellitus in healthy individuals. sE-selectin is specific for the endothelium and is increased in coronary artery disease and diabetes mellitus. sE-selectin is also associated with diabetic risk. The endothelium-specific marker, soluble thrombomodulin, is associated with severity of coronary artery disease, stroke or peripheral occlusive arterial disease and is not increased in healthy or asymptomatic subjects. Interestingly, thrombomodulin decreases during treatment of hypercholesterolemia or hyperhomocysteinemia. In contrast, von Willebrand factor is the best endothelial biomarker and predicts risk for ischemic heart disease or stroke.

Cellular adhesion molecules and their relationship with measures of obesity and metabolic syndrome in a multiethnic population

BACKGROUND

The relationships between adhesion molecules and measures of obesity and metabolic syndrome in different ethnic populations are unclear.

OBJECTIVE

Our aim was to study the association between body mass index (BMI), waist-hip ratio (WHR) and the parameters of the metabolic syndrome with four different adhesion molecules, adjusting for potential confounders, in men and women from different ethnic origins.

METHODS

Soluble plasma adhesion molecules (sP-selectin, sE-selectin, intracellular adhesion molecule-1 (sICAM-1) and vascular cell adhesion molecule-1 (sVCAM-1) were measured in 261 white (120 women), 188 African origin (99 women) and 215 South Asian (99 women) individuals living in South London. All were free from coronary heart disease (CHD), stroke and other cardiovascular disease (CVD), diabetes, drug therapy for hypertension or high lipids, hormone replacement therapy or oral contraceptive pill.

RESULTS

sE-selectin levels were positively and significantly associated with both BMI (P < 0.001) and WHR (P < 0.001). There were no major interactions with either sex or ethnicity. The strength of the association between sE-selectin and WHR was not affected by multiple adjustment for age, sex, ethnicity smoking, blood pressure, serum lipids and insulin (P < 0.001), whereas the association with BMI was attenuated by multiple adjustments (P = 0.037). An approximate 2% higher sE-selectin levels would be associated with a 1 unit higher BMI and a 0.01 unit greater WHR.

CONCLUSIONS

The relationships between adhesion molecules and conventional measures of obesity are adhesion molecule specific and are strongest between sE-selectin and WHR.

Effects of angiotensin II-receptor blockers on soluble cell adhesion molecule levels in uncomplicated systemic hypertension: An observational, controlled pilot study in Taiwanese adults

BACKGROUND

Controversy exists as to whether individuals with hypertension without risk factors for atherosclerosis (eg, diabetes mellitus, dyslipidemia.

OBJECTIVE

The aim of this study was to determine whether (1) levels of solubleCAMs (sCAMs) (soluble E-selectin [sE-selectin], soluble intercellular adhesion molecule-1 [sICAM-1 ], soluble vascular cell adhesion molecule-1 [sVCAM-1 ], and von Willebrand factor [vWF]) are elevated in Taiwanese adults with uncomplicated essential hypertension without other risk factors; (2) CAM levels increase with severity (stage) of hypertension; and (3) monotherapy with the angiotensin II-receptor blocker (ARB) irbesartan modulates CAM expression in a subgroup of these patients.

METHODS

This observational, controlled pilot study was conducted at the Hypertension Clinic, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan. Adult patients with uncomplicated essential hypertension without other risk factors (eg, diabetes mellitus, dyslipidemia, obesity) and normotensive controls were eligible. Blood pressure (BP) was determined using 24-hour ambulatory BP monitoring (ABPM) in all participants, and the staging of hypertension was classified based on criteria in The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (normotensive, prehypertension, stage I hypertension, and stage II hypertension). The SCAM levels and 24-hour ABPM were measured before and after 8 weeks of open-label irbesartan monotherapy in a subgroup of the patients with hypertension. Patients who had difficulty achieving the target BP values on irbesartan monotherapy were treated with combination therapy (2 or 3 antihypertensive agents); levels of sCAMs were not measured in these patients. Plasma levels of sE-selectin, the sCAMs, and vWF were measured using enzyme-linked immunosorbent assay.

RESULTS

The study comprised 61 patients with uncomplicated essentialhypertension (33 men and 28 women; mean [SD] age, 51 [12] years) and 17 normotensive controls (11 men, 6 women; mean [SD] age, 52 [ 11 ] years). The mean (SD) dose of irbesartan was 243 (63) mg. Hypertensive patients had significantly higher circulating levels of sICAM-1 compared with normotensive controls (P = 0.009). No significant differences in levels of sVCAM-1, sE-selectin, or vWF were found between hypertensive patients and controls. The mean sICAM-1 level was significantly higher in the prehypertensive patients compared with normotensive controls (P = 0.03). The mean sE-selectin level was significantly higher in the patients with stage I hypertension compared with the prehypertensive group (P = 0.01). The 18 patients given 8 weeks of irbesartan monotherapy showed a significant decrease from baseline in systolic and diastolic BP (both, P = 0.001) and sE-selectin (P= 0.006), but not in sVCAM-1 or sICAM. Forty-three patients did not reach target BP on irbesartan monotherapy and thus were treated with combination therapy.

CONCLUSIONS

Based on the results of this observational, controlled pilotstudy in Taiwanese patients, we suggest that ARB therapy, in addition to reducing BP, has the potential to suppress CAM expression and to improve endothelial dysfunction in hypertension.