Future Treatment of Hypertension: Shifting the Focus from Blood Pressure Lowering to Arterial Stiffness Modulation?

Interaction between body mass index and blood pressure on the risk of vascular stiffness : A community-based cross-sectional study and implications for nursing

Objective

This study aimed to analyze associations between body mass index (BMI) and vascular measurements (brachial ankle pulse wave velocity [baPWV] and ankle-brachial index [ABI]), whether blood pressure (BP) was involved in the relationship, and implications for nursing.

Methods

A cross-sectional study was conducted, including 1,894 middle-aged and older adults who underwent routine health screening at a community medical center in the Zhangjiang community in Shanghai, China. Participants were divided into three groups based on BMI: normal weight (n = 1,202), overweight (n = 480), and obese (n = 212). Multivariate linear regression models and smooth curve fittings were used to evaluate the associations between BMI and indices of vascular stiffness. Mediation analysis examined whether blood pressure mediate the association between BMI and vascular stiffness.

Results

Multiple linear regression analysis showed that BMI to be significantly and negatively associated with baPWV (β = -0.06 [-0.10, -0.03]) and ABI (β = -0.004 [-0.005, -0.003]), respectively. The interaction test results of systolic blood pressure (SBP) in the relationship between BMI and baPWV were significant (P for interaction = 0.01). After adjusting for age and sex, mediation analyses showed that BMI and baPWV were correlated (β = 0.090, P < 0.001) and mediated by SBP (β = 0.533, P < 0.001) and diastolic blood pressure (DBP) (β = 0.338, P < 0.001). A negative association was found between BMI and ABI (β = -0.135, P < 0.001), which appeared to be partially mediated by SBP (β = 0.124, P < 0.001) and DBP (β = 0.053, P < 0.001). Additional subgroup analysis based on blood pressure levels did not revealed statistically significant mediating effects.

Conclusions

Our findings showed conflicting associations between BMI and non-invasive vascular measurements of arterial stiffness. BP may have a biological interaction in the relationship between BMI and baPWV. Managing blood pressure and weight through comprehensive clinical care is crucial for preventing stiffness or blockage of vessels in middle-aged and older adults.

Association between Arteriosclerosis and Uncontrolled Blood Pressure in Patients with Essential Hypertension: Cross-Sectional Observational Study Results of the BEST Study

Whether arteriosclerosis can influence the hypertension control remains incompletely understood. We hypothesized that higher arteriosclerosis may be associated with uncontrolled hypertension. Arteriosclerosis was assessed by carotid femoral artery pulse wave velocity (CF-PWV) and uncontrolled hypertension (systolic blood pressure [BP] ≥130 mm Hg or diastolic BP ≥80 mm Hg). The multivariable-adjusted logistic regression was used for analysis. A total of 1,428 patients with essential hypertension (mean age 68 years, 49.6% male) were enrolled into the study from 2010 to 2017. The BP was uncontrolled in 50.7% of the participants and the mean level of CF-PWV was 12.3 m/s. All the cardiovascular risk factors were worse and CF-PWV was higher in patients with uncontrolled hypertension (all p < 0.05). Multivariable-adjusted logistic regression analysis showed that CF-PWV as a continuous variable (odd ratio [OR] 1.093, 95% confidence interval [CI] 1.046-1.142) was independently associated with uncontrolled hypertension, after male (OR 1.511) and total cholesterol (OR 1.167), followed by body mass index (OR 1.092), fasting plasma glucose (OR 1.075), and creatinine (OR 1.010) (all p < 0.05). As a binary variable, CF-PWV >12 m/s was also independently associated with uncontrolled hypertension (OR 1.690, 95% CI 1.320-2.164, p < 0.05). Arteriosclerosis is independently associated with uncontrolled BP in patients with hypertension.

Sustained-release isosorbide mononitrate as adjuvant treatment in isolated systolic hypertension in the elderly

Hypertension is one of the main cardiovascular risk factors. In the elderly, the most common form is isolated systolic hypertension, a consequence of the increase in arterial stiffness. None of the antihypertensives currently used affects arterial stiffness, whereas nitrates seem to have an effect. The aim of this work was to assess their effect on elderly patients with uncontrolled isolated systolic hypertension, defined as systolic blood pressure over 140 mmHg and diastolic blood pressure under 90 mmHg. The present study is a phase III, randomized, multicenter, double-blind, placebo-controlled clinical trial, conducted at the University Hospital La Princesa in Madrid. Patients of both sexes, aged 65 years or older, with poorly controlled isolated systolic hypertension, were treated with 40-60 mg of sustained-release isosorbide mononitrate or matching placebo for 12 weeks. The main objective was to assess the effect on clinical pulse pressure (PP); in addition, its effect on vascular function was evaluated. Analysis was performed by intention to treat. The study was registered at the European Union Clinical Trials Register (EUDRACT 2012-002988-10) and was funded by the Spanish Ministry of Health. A total of 58 patients with an average age of 77 years were enrolled, 32 were treated with nitrate, and 26 with placebo. No significant differences were found either in PP decline (5.28 vs 7.49 mmHg, p = 0.79) or in other variables, including parameters of vascular function. There were no differences in adverse events. The results of this study have not confirmed the benefit of nitrate treatment in isolated systolic hypertension or the improvement of vascular function.

Prognostic Value of Changes in Aortic Stiffness for Cardiovascular Outcomes and Mortality in Resistant Hypertension: a Cohort Study

The prognostic importance of changes in aortic stiffness for the occurrence of adverse cardiovascular outcomes and mortality has never been investigated in patients with resistant hypertension. We aimed to evaluate it in a prospective cohort of 442 resistant hypertension individuals. Changes in aortic stiffness were assessed by 2 carotid-femoral pulse wave velocity (CF-PWV) measurements performed over a median time interval of 4.7 years. Multivariate Cox analysis examined the associations between changes in CF-PWV (evaluated as continuous variables and categorized into quartiles and as increased/persistently high or reduced/persistently low) and the occurrence of total cardiovascular events (CVEs), major adverse CVEs, and cardiovascular/all-cause mortalities. During a median follow-up of 4.1 years after the second CF-PWV measurement, there were 49 total CVEs (42 major adverse CVEs) and 53 all-cause deaths (32 cardiovascular). As continuous variables, increments in absolute and relative changes in CF-PWV were associated with higher risks of CVEs and major adverse CVEs occurrence, but not of mortality. Divided into quartiles of CF-PWV changes, risks increased in the third and fourth quartile subgroups in relation to the reference first quartile subgroup (those with greatest CF-PWV reductions) for all outcomes. Patients who either increased or persisted with high CF-PWV had excess risks of cardiovascular morbidity/mortality, with hazard ratios ranging from 2.7 to 3.0, in relation to those who reduced or persisted with low CF-PWV values. In conclusion, reducing or preventing progression of aortic stiffness was associated with significant cardiovascular protection in patients with resistant hypertension, suggesting that it may be an additional clinical target of antihypertensive treatment.

Conductance artery stiffness impairs atrio-ventriculo-arterial coupling before manifestation of arterial hypertension or left ventricular hypertrophic remodelling

As part of normal ageing, conductance arteries lose their cushion function, left ventricle (LV) filling and also left atrial emptying are impaired. The relation between conductance artery stiffness and LV diastolic function is normally explained by arterial hypertension and LV hypertrophy as needed intermediaries. We examined whether age-related aortic stiffening may influence LV diastolic function in normal healthy subjects. Aortic distensibility and pulse wave velocity (PWV) were related to LV emptying and filling parameters and left atrial emptying parameters as determined by magnetic resonance imaging in 36 healthy young (< 35 years) and 16 healthy middle-aged and elderly (> 35 years) with normal arterial blood pressure and myocardial mass. In the overall cohort, total aorta PWV correlated to a decrease in LV peak-emptying volume (r = 0.43), LV peak-filling (r = 0.47), passive atrial emptying volume (r = 0.66), and an increase in active atrial emptying volume (r = 0.47) (all p < 0.001). PWV was correlated to passive atrial emptying volume even if only the > 35-year-old were considered (r = 0.53; p < 0.001). Total peripheral resistance demonstrated similar correlations as PWV, but in a regression analysis only the total aorta PWV was related to left atrial (LA) passive emptying volume. Via impaired ventriculo-arterial coupling, the increased aortic PWV seen with normal ageing hence affects atrio-ventricular coupling, before increased aortic PWV is associated with significantly increased arterial blood pressure or LV hypertrophic remodelling. Our findings reinforce the existence of atrio-ventriculo-arterial coupling and suggest aortic distensibility should be considered an early therapeutic target to avoid diastolic dysfunction of the LV.

Gender-specific associations between apolipoprotein A1 and arterial stiffness in patients with nonalcoholic fatty liver disease

Background

Lipid metabolism factors may play an important role in the progression of nonalcoholic fatty liver disease (NAFLD) and its related cardiovascular dysfunctions. The study aims to assess whether Apolipoprotein A-1 (ApoA1) was associated with vascular stiffness in NAFLD patients.

Methods

From 2012 to 2013, we included 2,295 non-alcohol users with fatty liver disease (1,306 male patients) and completely excluded subjects who drank any alcohol ever to eliminate the effect of alcohol intake. The serum ApoA1 levels and the brachial-ankle pulse wave velocity (baPWV) were measured.

Results

The baPWV in men was much higher than in female patients (1,412.79 cm/s vs. 1,358.69 cm/s, P < 0.001). ApoA1 level was positively associated with baPWV odd ratio (OR), 4.18; 95% confidence interval (CI) [1.16-15.1], P < 0.05) in patients with AST/ALT < 1 and (OR, 4.70; 95% CI [1.36-16.23], P < 0.05) in patients with AST/ALT ≥ 1 respectively. Only arterial stiffness in men was associated with ApoA1 (OR, 3.96; 95% CI [1.29-12.30], P < 0.05) in logistics regression models adjusted for age, gender, body mass index, education attainment, physical activity, smoking, history of hypertension and high-density lipoprotein. The relationship between ApoA1 and baPWV in male NAFLD patients remained significant (confidence, 156.42; 95% CI [49.34-263.50], P < 0.05) in the fully adjusted linear regression model.

Conclusion

The serum ApoA1 was associated with arterial stiffness in male NAFLD patients. Increased ApoA1 level should be considered as an independent risk factor for arterial stiffness in male NAFLD patients, suggesting that NAFLD may alter arterial stiffness by "ApoA1-related" mechanism in men.

Prognostic Impact of Aortic Stiffness in Patients With Resistant Hypertension

The prognostic importance of aortic stiffness in patients with resistant hypertension has never been investigated. We aimed to evaluate it for the occurrence of adverse cardiovascular outcomes and mortality in a prospective cohort of resistant hypertensive patients. Aortic stiffness was assessed by carotid-femoral pulse wave velocity (cf-PWV) at baseline in 891 resistant hypertensive patients who were followed-up for a median of 7.8 years. Multivariate Cox analysis examined the associations between cf-PWV and the occurrence of total cardiovascular events (CVE), major adverse CVEs, and cardiovascular and all-cause mortalities. The improvement in risk stratification was assessed by C statistics and the integrated discrimination improvement index. During follow-up, 138 patients had a CVE (123 major adverse CVE) and 142 patients died (91 from cardiovascular causes). The cf-PWV, analyzed either as a continuous or as a categorical variable, predicted all cardiovascular and mortality outcomes. Patients with increased aortic stiffness (cf-PWV ≥10 m/s after correction for the white-coat effect, or uncorrected directly measured ≥11 m/s) had a significant 2.2- to 2.6-fold increased risk of CVEs and mortality, after adjustments for other risk factors, including 24-hour ambulatory blood pressures and dipping patterns. Aortic stiffness significantly improved cardiovascular risk stratification, with integrated discrimination improvement indices ranging from 13% (for total CVEs) to 18% (for major adverse CVE). In conclusion, increased aortic stiffness predicts adverse cardiovascular outcomes and mortality and improves cardiovascular risk stratification in resistant hypertensive patients. cf-PWV measurement should be included into the routine clinical management of resistant hypertension.

Continuous non-invasive determination of nocturnal blood pressure variation using photoplethysmographic pulse wave signals: comparison of pulse propagation time, pulse transit time and RR-interval

OBJECTIVE

Cardiovascular diseases are the leading cause of death, whereas nocturnal ambulatory blood pressure (BP) is the most potent predictor for cardiovascular risk. The volume clamp and pulse transit time (PTT) are common methods for continuous non-invasive BP measurement, but have drawbacks during unsupervised ambulatory use and undisturbed sleep. The pulse propagation time (PPT), defined as the time between pulse wave systolic peak and diastolic peak, provides valid information about the pressure pulse waveform. However, the use of PPT for nocturnal BP variation determination and whether such variation is affected by BP or heart rate (i.e. RR-interval or RRI) has not been investigated.

APPROACH

To assess whether the PPT method is suitable for ubiquitous nocturnal BP monitoring, we compared systolic blood pressure (SBP) estimates derived from PPT, PTT, and RRI signals with parallel recorded BP measurements. The RRI-derived SBP signals were used as a baseline for testing a potential heart rate dependency. This work provides an overview of BP measurements, presents the developed real-time signal analysis, and describes the performance assessment. The signal analysis was validated with data records from 42 subjects acquired from an ergometry and sleep laboratory in equal parts.

MAIN RESULTS

The algorithms applied to the ergometry laboratory database achieved a correlation coefficient between reference SBP and estimated SBP_PPT of 0.89 (p  <  0.001) with bias 0.1 mmHg and limits of agreement (LoA)  -29.8 to 30.0 mmHg, SBP_PTT of 0.97 (p  <  0.001) with bias 0.0 mmHg and LoA  -15.2 to 15.3 mmHg, and SBP_RRI of 0.96 (p  <  0.001) with bias 0.0 mmHg and LoA  -19.5 to 19.5 mmHg. For the sleep laboratory database, the correlation coefficient was 0.95 (p  <  0.001) with bias 0.2 mmHg and LoA  -18.3 to 18.8 mmHg for SBP_PPT, 0.88 (p  <  0.001) with bias 0.0 mmHg and LoA  -25.0 to 24.9 mmHg for SBP_PTT, and 0.88 (p  <  0.001) with bias of 0.1 mmHg and LoA  -23.6 to 23.7 mmHg for SBP_RRI. A heart rate dependency of PPT or PTT could not be found. The analysis of variance shows no significant differences between the reference SBP values and the estimated values for either the ergometry (F(3, 627)  =  2.27, p  =  0.08) or the sleep laboratory (F(3, 327)  =  2.28, p  =  0.08).

SIGNIFICANCE

In conclusion, the PPT method seems to be an interesting alternative for continuous determination of SBP during simplified cardiovascular monitoring and sleep screening compared to more expensive devices based on volume clamp or PTT methods.

Wnt signaling in cardiovascular disease: opportunities and challenges

PURPOSE OF REVIEW

Cardiometabolic diseases increasingly afflict our aging, dysmetabolic population. Complex signals regulating low-density lipoprotein receptor-related protein (LRP) and frizzled protein family members - the plasma membrane receptors for the cadre of Wnt polypeptide morphogens - contribute to the control of cardiovascular homeostasis.

RECENT FINDINGS

Both canonical (β-catenin-dependent) and noncanonical (β-catenin-independent) Wnt signaling programs control vascular smooth muscle (VSM) cell phenotypic modulation in cardiometabolic disease. LRP6 limits VSM proliferation, reduces arteriosclerotic transcriptional reprogramming, and preserves insulin sensitivity while LRP5 restrains foam cell formation. Adipose, skeletal muscle, macrophages, and VSM have emerged as important sources of circulating Wnt ligands that are dynamically regulated during the prediabetes-diabetes transition with cardiometabolic consequences. Platelets release Dkk1, a LRP5/LRP6 inhibitor that induces endothelial inflammation and the prosclerotic endothelial-mesenchymal transition. By contrast, inhibitory secreted frizzled-related proteins shape the Wnt signaling milieu to limit myocardial inflammation with ischemia-reperfusion injury. VSM sclerostin, an inhibitor of canonical Wnt signaling in bone, restrains remodeling that predisposes to aneurysm formation, and is downregulated in aneurysmal vessels by epigenetic methylation.

SUMMARY

Components of the Wnt signaling cascade represent novel targets for pharmacological intervention in cardiometabolic disease. Conversely, strategies targeting the Wnt signaling cascade for other therapeutic purposes will have cardiovascular consequences that must be delineated to establish clinically useful pharmacokinetic-pharmacodynamic relationships.

The Contribution of Inflammation to the Development of Hypertension Mediated by Increased Arterial Stiffness

BACKGROUND

The mechanisms underlying the possible contribution of chronic inflammation to the development of hypertension remain unclear. We examined the longitudinal association of inflammation with the progression of vascular and/or renal abnormalities in the development of hypertension.

METHODS AND RESULTS

In 3274 middle-aged Japanese men without hypertension at the study baseline, brachial-ankle pulse wave velocity, blood pressure, estimated glomerular filtration rate, and serum CRP (C reactive protein) levels were measured annually during a 9-year period. During this study period, 474 participants (14.5%) developed hypertension. Analysis of the repeated-measures data revealed that sustained elevation of serum CRP levels was associated with a longitudinal increase of the brachial-ankle pulse wave velocity. A linear mixed model analysis revealed that higher log-transformed serum CRP values (log CRP) at each measurement were associated with a higher annual increase of the brachial-ankle pulse wave velocity (estimate=32.553±11.635 cm/s per log CRP, P=0.018), and that higher values of the brachial-ankle pulse wave velocity at each measurement were associated with a higher annual elevation of blood pressure (estimate=0.025±0.002 mm Hg per log CRP, P<0.001).

CONCLUSIONS

In middle-aged Japanese men without hypertension at study baseline, long-term active inflammation appears to be associated with a longitudinal increase of arterial stiffness. In turn, this longitudinal increase of arterial stiffness appears to be associated with longitudinal elevation of blood pressure to the hypertensive range. Thus, systemic inflammation may play a role in the pathogenesis of hypertension by the progression of arterial stiffness.

Effect of endoskeleton stent graft design on pulse wave velocity in patients undergoing endovascular repair of the aortic arch

PURPOSE

Pulse wave velocity (PWV), which measures vascular stiffness, is a powerful predictor of cardiovascular event. Treatment of aneurysms with endovascular prosthesis has been reported to increase PWV. The purpose of this study was to evaluate whether an endoskeleton stent graft design has less effect on PWV than the exoskeleton stent graft design.

METHODS

Between July 2008 and September 2016, 74 patients underwent endovascular treatment of aortic arch aneurysm in our institution. PWV before and after surgery were compared between those who underwent treatment with Najuta, an endoskeleton stent graft (n = 51), and those treated with other commercially available exoskeleton stent grafts (n = 23).

RESULTS

Preoperative PWV (endoskeleton: 2004 ± 379.2 cm/s vs. exoskeleton: 2083 ± 454.5 cm/s, p = 0.47) was similar between the two groups. Factors that were associated with preoperative PWV were age (r = 0.37, 95% CI 0.15-0.56, p = 0.002) and mean arterial pressure (r = 0.53, 95% CI 0.34-0.68, p < 0.001). There was a significant increase in PWV in patients treated by exoskeleton stent grafts (before: 2083 ± 454.5 cm/s vs. after: 2305 ± 479.7 cm/s, p = 0.023) while endoskeleton stent graft showed no change in PWV (before: 2003 ± 379.2 vs. after: 2010 ± 521.1, p = 0.56). In a multivariate analysis, mean arterial pressure (coef 17.5, 95% CI 6.48-28.59, p = 0.002) and exoskeleton stent graft (coef 359.4, 95% CI 89.36-629.43, p = 0.010) were independently associated with PWV after surgery.

CONCLUSIONS

Physiological changes after endovascular treatment should be considered including effect on vascular stiffness. Endoskeleton stent graft may provide aneurysm repair with minimum effect in PWV after surgery.

miR-181b regulates vascular stiffness age dependently in part by regulating TGF-β signaling

BACKGROUND

Endothelial dysfunction and arterial stiffening play major roles in cardiovascular diseases. The critical role for the miR-181 family in vascular inflammation has been documented. Here we tested whether the miR-181 family can influence the pathogenesis of hypertension and vascular stiffening.

METHODS AND RESULTS

qPCR data showed a significant decrease in miR-181b expression in the aorta of the older mice. Eight miR-181a1/b1-/- mice and wild types (C57BL6J:WT) were followed weekly for pulse wave velocity (PWV) and blood pressure measurements. After 20 weeks, the mice were tested for endothelial function and aortic modulus. There was a progressive increase in PWV and higher systolic blood pressure in miR-181a1/b1-/- mice compared with WTs. At 21 weeks, aortic modulus was significantly greater in the miR-181a1/b1-/- group, and serum TGF-β was found to be elevated at this time. A luciferase reporter assay confirmed miR-181b targets TGF-βi (TGF-β induced) in the aortic VSMCs. In contrast, wire myography revealed unaltered endothelial function along with higher nitric oxide production in the miR-181a1/b1-/- group. Cultured VECs and VSMCs from the mouse aorta showed more secreted TGF-β in VSMCs of the miR-181a1/b1-/- group; whereas, no change was observed from VECs. Circulating levels of angiotensin II were similar in both groups. Treatment with losartan (0.6 g/L) prevented the increase in PWV, blood pressure, and vascular stiffness in miR-181a1/b1-/- mice. Immunohistochemistry and western blot for p-SMAD2/3 validated the inhibitory effect of losartan on TGF-β signaling in miR-181a1/b1-/- mice.

CONCLUSIONS

Decreased miR-181b with aging plays a critical role in ECM remodeling by removing the brake on the TGF-β, pSMAD2/3 pathway.

Mean Platelet Volume and Arterial Stiffness - Clinical Relationship and Common Genetic Variability

Vessel wall stiffening is an important clinical parameter, but it is unknown whether platelets, key elements in the pathogenesis of arterial thrombosis, are associated with arterial stiffness. The present studies sought to determine whether mean platelet volume (MPV), a potential marker of platelet activation, is linked to vascular elasticity as assessed by the augmentation index (AIx), in 15,010 individuals from the population-based Gutenberg Health Study. Multivariable analysis showed that MPV in both males (β 0.776; 95^thCI [0.250;1.16]; p = 0.0024) and females (β 0.881[0.328;1.43]; p = 0.0018) is strongly associated with AIx. Individuals with MPV and AIx above the sex-specific medians had worse survival. Association analysis between MPV-related genetic variants and arterial stiffness identified four genetic variants in males and one in females related with AIx. Cox regression analysis for mortality identified one of these joint genetic variants close to ring finger protein 145 gene (RNF145, rs10076782) linked with increased mortality (hazard ratio 2.02; 95^thCI [1.35;3.02]; p = 0.00061). Thus, these population-based data demonstrate a close relation between platelet volume as a potential marker of platelet activation and arterial stiffness in both sexes. Further research is warranted to further elucidate the mechanisms underlying larger platelets‘ role in arterial stiffening including the role of shared common genetics.

Single nucleotide polymorphism of adiponectin +276 G/T is associated with the susceptibility to essential hypertension in a Turkish population

BACKGROUND

It is well known that arterial stiffness is associated with hypertension. Recent studies have shown that adiponectin +276 G/T, ACE I/D, AGTR1 A1166C, and eNOS E298D polymorphisms are likely to be risk factors for arterial stiffness. In this study, we aimed to investigate possible associations between these single-nucleotide polymorphisms (SNPs) and essential hypertension in a Turkish population.

METHODS

The study population consisted of 170 patients who were diagnosed with essential hypertension and 170 sex- and age-matched controls. Genotyping of adiponectin +276 G/T, ACE I/D, AGTR1 A1166C, and eNOS E298D SNPs were performed using real-time polymerase chain reaction and commercially produced kits.

RESULTS

The percentage of the adiponectin +276 T allele carriers was significantly higher in the patients with hypertension (33%) than in the controls (25%, p < 0.011). Through multiple logistic regression analysis, the adiponectin +276 T allele carrier was found to be associated with an increased risk of hypertension (TT vs. GG and TG: odds ratio = 3.318, p = 0.014, 95% confidence interval: 1.269-8.678). The genotype distributions or allelic frequencies of ACE I/D, AGTR1 A1166C, and eNOS E298D SNPs did not significantly differ between the patients with hypertension and the controls.

CONCLUSION

The present study demonstrated that the adiponectin +276 G/T SNP is likely to be a risk factor for essential hypertension in a Turkish population.

Hypertension-linked mechanical changes of rat gut

Hypertension is the most prevalent risk factor for cardiovascular disease caused by a persistent increase in arterial blood pressure that has lasting effects on the mechanical properties of affected tissues like myocardium and blood vessels. Our group recently discovered that gut dysbiosis is linked to hypertension in several animal models and humans; however, whether hypertension influences the gut's mechanical properties remains unknown. In this study, we evaluated the hypothesis that hypertension increases fibrosis and thus mechanical properties of the gut. A custom indentation system was used to test colon samples from Wistar Kyoto (WKY) normotensive rats and Spontaneously Hypertensive Rats (SHR). Using force-displacement data, we derived an steady-state modulus metric to quantify mechanical properties of gastrointestinal tissue. We observed that SHR proximal colon has a mean steady-state modulus almost 3 times greater than WKY control rat colon (5.11±1.58kPa and 18.17±11.45kPa, respectively). These increases were associated with increase in vascular smooth muscle cells layer and collagen deposition in the intestinal wall in the SHR.

STATEMENT OF SIGNIFICANCE

Mechanical characterization of biological materials can provide insight into health and disease of tissue. Recent investigations into a variety of cardiovascular pathologies show coincident changes in the microbiome and pathology of the gut. In this study, we sought to quantify changes in the gut in hypertension through mechanical characterization. Our methods and simple models for characterization, adapted from Hertz indentation models, prove useful to identify a meaningful steady-state modulus metric for small and irregular tissues from laboratory animals. Our data, for the first time, establish a stiffening of the gut wall in Spontaneously Hypertensive Rats. This observation suggests significant structural and functional changes in the gut correlate with hypertension, and future experiments are warranted to explore the specific causal relationship between dysbiosis, fibrosis, and stiffening in the gut during the development and maintenance of hypertension.

Differential effects of lercanidipine/enalapril versus amlodipine/enalapril and hydrochlorothiazide/enalapril on target organ damage and sympathetic activation in non-obese essential hypertensive subjects

OBJECTIVE

The aim of the present study was to compare the effects of the combination of lercanidipine/enalapril versus amlodipine/enalapril and hydrochlorothiazide/enalapril on blood pressure, target organ damage and sympathetic activation in patients with grade 2 essential hypertension.

RESEARCH DESIGN AND METHODS

This was a 3 month, randomized, blinded-endpoint study in essential hypertensive patients.

MAIN OUTCOME MEASURES

Office and ambulatory blood pressure, arterial stiffness, urinary albumin to creatinine ratio, renal arterial resistive index, and muscle sympathetic nerve activity were evaluated at baseline, after a 2 week run-in placebo period, at 1 month and at 3 months.

RESULTS

In total, 56 patients were assigned to lercanidipine/enalapril (n = 19), enalapril/amlodipine (n = 18) and hydrochlorothiazide/enalapril (n = 19). Each pharmacological combination tested was effective in reducing office blood pressure at 1 month and 3 months, and 24 h ambulatory blood pressure at 3 months. Renal arterial resistive index (RI) significantly improved at 1 month and 3 months compared with baseline in all groups. However in the lercanidipine/enalapril and hydrochlorothiazide/enalapril groups, RI was favorably reduced (0.53 ± 0.03 and 0.54 ± 0.04 respectively, p < 0.05) in comparison with the enalapril/amlodipine RI value (0.57 ± 0.03) at 3 months. Moreover, after 3 months of treatment, a significant decrease (by -5.47 bursts/min) (p < 0.05) in muscle sympathetic nerve activity was observed in the lercanidipine/enalapril group (50.79 ± 6.49) compared with baseline (56.26 ± 6.05), while no differences were detected in the amlodipine/enalapril and hydrochlorothiazide/enalapril groups.

CONCLUSIONS

Our study provides evidence of the efficacy of the lercanidipine/enalapril combination in ameliorating hypertension-related target organ damage and in reducing sympathetic overdrive.

Aspects of Hyperglycemia Contribution to Arterial Stiffness and Cardiovascular Complications in Patients With Type 1 Diabetes

Controlling the blood glucose level is of outmost importance for the prevention of the micro- and macrovascular diabetic complications observed in patients with type 1 diabetes (T1D). Although the pathogenesis behind the complex cascade of complications is far from solved, one possible mechanism could be a negative effect of glucose on the arteries resulting in a stiffening of the arteries and ultimately in vascular complications. Intriguingly, patients with T1D have been shown to suffer from premature arterial aging compared to nondiabetic subjects-an association that is even more evident in the presence of diabetic complications such as diabetic nephropathy. Arterial stiffness has in several patient populations been shown to independently predict cardiovascular disease. However, interventional studies aimed at attenuating arterial stiffness to reduce cardiovascular disease in T1D are yet to come. Moreover, most of the data on pharmacological treatments of arterial stiffening are directed toward pathophysiological pathways other than hyperglycemia. Interestingly, the sodium-glucose transport-2 (SGLT2) inhibitor empagliflozin was recently shown to reduce both blood pressure and arterial stiffness in patients with type 2 diabetes. Whether, these effects can also be replicated in patients with T1D is an intriguing question. Tight metabolic and antihypertensive control are still of central importance for the prevention and the treatment of diabetic complications. However, the need for a noninvasive intermediate marker to identify at risk patients for aggressive treatment is evident. One such tool might be arterial stiffness linking diabetes to increased cardiovascular risk. Future research efforts exploring large-scale databases will play a key role in the identification of other clinically useful markers.

Measurement of Arterial Stiffness: A Novel Tool of Risk Stratification in Hypertension

Cardiovascular diseases are the leading causes of morbidity and mortality in industrialized countries worldwide, despite highly effective preventive treatments available. As a difference continues to exist between the estimated and true number of events, further improvement of risk stratification is an essential part of cardiovascular research.Among hypertensive patients measurement of arterial stiffness parameters, like carotid-femoral pulse wave velocity (cfPWV) or brachial-ankle pulse wave velocity (baPWV) can contribute to the identification of high-risk subpopulation of patients. This is a hot topic of vascular research including the possibility of the non-invasive measurement of central hemodynamics, wave reflections and recently, 24-h arterial stiffness monitoring as well. This chapter discusses the past and the present of this area including the scientific achievements with cfPWV, baPWV and other measures, provides a short overview of methodologies and the representation of arterial stiffness parameters in guidelines.