Systolic hypertension in the elderly: arterial wall mechanical properties and the renin-angiotensin-aldosterone system

Effects of nitroglycerin-induced vasodilation on elastic and muscular artery stiffness in older Veterans

Vascular smooth muscle tone may play an important role in the physiology of increased arterial stiffness that occurs with aging. This study evaluated the impact of smooth muscle tone on arterial stiffness in older individuals following nitroglycerin-induced vasodilation in elastic and muscular arteries. Forty older Veterans (≥60 years old) without known cardiovascular disease were included in this study. Twenty Veterans were included as hypertensive participants (70.8 ± 6.6 years, 10 females), and 20 were included as normotensive controls (72.0 ± 9.3 years, 8 females). Nitroglycerin (NTG)-induced changes in arterial stiffness were measured locally with vascular ultrasound in the carotid and brachial arteries and regionally by carotid-femoral pulse wave velocity (cfPWV) with tonometry. With NTG treatment, both hypertensive participants and normotensive controls Veterans showed increased carotid PWV (6.4 ± 1.3 m/s to 7.2 ± 1.4 m/s, Δ 0.8 ± 1.1 m/s, p = 0.007) and cfPWV (8.6 ± 1.9 m/s to 9.5 ± 2.4 m/s, Δ 0.9 ± 2.3 m/s, p = 0.020) but did not show changes in brachial PWV (11.2 ± 2.4 m/s to 11.1 ± 2.2 m/s, Δ -0.2 ± 2.5 m/s, p = 0.72). The carotid artery was dilated more in control participants than hypertensive Veterans (Δ 0.54 ± 0.19 mm vs. 0.42 ± 0.12 mm, p = 0.022). Brachial artery dilation was similar between the two groups (Δ 0.55 ± 0.26 mm vs. 0.51 ± 0.20 mm, p = 0.46). In older Veterans without known cardiovascular disease, NTG-induced vasodilation increased elastic artery stiffness but did not change muscular artery stiffness. Increased central arterial stiffness and a decrease in the arterial stiffness gradient could offset some of the benefits of lowering blood pressure in older patients who are prescribed vasodilators as an antihypertensive therapy. Elastic artery stiffening with vasodilation warrants further investigation, as it may be important for antihypertensive medication selection and influence CVD development.

Prevalence of hypertension among individuals with diabetes and its determinants: Evidences from the National Family Health Survey 2015-16, India

BACKGROUND

The incidence of Diabetes mellitus (DM) has escalated in recent decades, and the risk of diabetes-related mortality has increased dramatically due to the co-existence of hypertension (HTN). DM and HTN, having similar aetiology and disease mechanism, are influenced by lifestyle factors and greatly contribute to critical health complications.

AIM

The present study attempted to explore the co-existence of DM-HTN and the potential determinants considering rapid upsurge of both the diseases.

SUBJECTS AND METHODS

National Family Health Survey data were used, which included 7092 adult diabetic individuals, to find out the prevalence rate of HTN in diabetic persons in India. Appropriate statistical analyses were performed to accomplish the study objectives.

RESULTS

Prevalence rate of HTN in diabetic individuals was approximately 37%. Higher BMI was associated with DM-HTN co-existence. In males, increased age, higher BMI, alcohol consumption, poorest wealth index, and non-smoking (tobacco) were the significant determinants of the co-existence of DM-HTN, while in females, they were increased age, higher BMI, and geographical region.

CONCLUSION

This study unveiled the significance of healthy lifestyle maintenance and equitable health care services to prevent HTN among the diabetics, along with promotion of the awareness and management of DM and HTN through appropriate pharmacological treatments.

Carotid Artery Stiffening With Aging: Structural Versus Load-Dependent Mechanisms in MESA (the Multi-Ethnic Study of Atherosclerosis)

Elastic arteries stiffen via 2 main mechanisms: (1) load-dependent stiffening from higher blood pressure and (2) structural stiffening due to changes in the vessel wall. Differentiating these closely coupled mechanisms is important to understanding vascular aging. MESA (Multi-Ethnic Study of Atherosclerosis) participants with B-mode carotid ultrasound and brachial blood pressure at exam 1 and exam 5 (year 10) were included in this study (n=2604). Peterson and Young elastic moduli were calculated to represent total stiffness. Structural stiffness was calculated by adjusting Peterson and Young elastic moduli to a standard blood pressure of 120/80 mm Hg with participant-specific models. Load-dependent stiffness was the difference between total and structural stiffness. Changes in carotid artery stiffness mechanisms over 10 years were compared by age groups with ANCOVA models adjusted for baseline cardiovascular disease risk factors. The 75- to 84-year age group had the greatest change in total, structural, and load-dependent stiffening compared with younger groups (P<0.05). Only age and cessation of antihypertensive medication were predictive of structural stiffening, whereas age, race/ethnicity, education, blood pressure, cholesterol, and antihypertensive medication were predictive of increased load-dependent stiffening. On average, structural stiffening accounted for the vast majority of total stiffening, but 37% of participants had more load-dependent than structural stiffening. Rates of structural and load-dependent carotid artery stiffening increased with age. Structural stiffening was consistently observed, and load-dependent stiffening was highly variable. Heterogeneity in arterial stiffening mechanisms with aging may influence cardiovascular disease development.

The role of body mass index in the association between dietary sodium intake and blood pressure: A mediation analysis with NHANES

BACKGROUND AND AIMS

Recent research demonstrated that obesity and high dietary sodium intake, the two established risk factors for hypertension, were associated with each other. The objective was to investigate the potential indirect effect of sodium intake on blood pressure via body mass index (BMI).

METHODS AND RESULTS

Using ten years data from US NHANES (2007-2016), the study included adult participants (>20 years old) who were not taking antihypertensive medications and without baseline diseases (n = 12,262). BMI was modelled as the mediator of sodium intake on systolic and diastolic blood pressure, adjusted for age, sex, socioeconomic status, smoking, drinking, physical activity, calorie intake, fluid intake and potassium intake. Mediation analysis was performed to evaluate total effect, direct effect and indirect effect via BMI. Subgroup analyses based on three age subgroups (20-40, 41-60 and ≥61 years old) were performed. The mean age was 39.29 (13.4) years and 53.1 (0.45) % were males. The mean BMI was 27.8 (6.20) kg/m². Overall, 1 g/d increase in sodium intake was associated with an increased systolic blood pressure by 0.36 (95% confidence interval 0.14 to 0.58) mmHg, with a direct effect (0.14 (0.09-0.19)) and an indirect effect via BMI (0.23 (0.02-0.44)). The indirect effect was mainly observed in participants ≤60 years old.

CONCLUSION

Sodium intake showed both direct effect and indirect effect (via BMI) on systolic blood pressure in US NHANES. The findings provide evidence for combining sodium restriction and weight reduction measures for prevention of hypertension. Cautions should be taken when generalizing the findings to other populations with lower average BMI.

Epigenetic dysregulation in cardiovascular aging and disease

Cardiovascular disease (CVD) is the leading cause of mortality and morbidity for all sexes, racial and ethnic groups. Age, and its associated physiological and pathological consequences, exacerbate CVD incidence and progression, while modulation of biological age with interventions track with cardiovascular health. Despite the strong link between aging and CVD, surprisingly few studies have directly investigated heart failure and vascular dysfunction in aged models and subjects. Nevertheless, strong correlations have been found between heart disease, atherosclerosis, hypertension, fibrosis, and regeneration efficiency with senescent cell burden and its proinflammatory sequelae. In agreement, senotherapeutics have had success in reducing the detrimental effects in experimental models of cardiovascular aging and disease. Aside from senotherapeutics, cellular reprogramming strategies targeting epigenetic enzymes remain an unexplored yet viable option for reversing or delaying CVD. Epigenetic alterations comprising local and global changes in DNA and histone modifications, transcription factor binding, disorganization of the nuclear lamina, and misfolding of the genome are hallmarks of aging. Limited studies in the aging cardiovascular system of murine models or human patient samples have identified strong correlations between the epigenome, age, and senescence. Here, we compile the findings in published studies linking epigenetic changes to CVD and identify clear themes of epigenetic deregulation during aging. Pending direct investigation of these general mechanisms in aged tissues, this review predicts that future work will establish epigenetic rejuvenation as a potent method to delay CVD.

Determinants of hypertension among patients with type 2 diabetes mellitus on follow-up at Tikur Anbessa Specialized Hospital, Addis Ababa: A case-control study

INTRODUCTION

Hypertension (HTN) in patients with diabetes mellitus (DM) is a common problem that increases the risk of mortality and morbidity, and lowers the quality of life. Despite the disproportionately high burden of HTN in DM patients, determinants for the comorbidity have not been sufficiently explored. Therefore, this study aimed to identify the determinants of HTN among patients with type 2 diabetes mellitus on follow-up at Tikur Anbessa Specialized Hospital.

METHODS AND MATERIALS

We conducted a hospital-based unmatched case-control study at Tikur Anbessa Specialized Hospital on 386 randomly selected patients with type 2 diabetes on follow-up (200 cases and 186 controls). We collected data by using a structured interviewer-administered questionnaire and data extraction form. To identify determinants of hypertension, a multivariable binary logistic regression was fitted, and the findings are presented using adjusted odds ratio (AOR) with 95% confidence interval (CI).

RESULTS

The mean reported age (±SD) of the cases and the controls was 60.3 (±9.9) and 55.3 (±11.3) years, respectively. The eight identified independent determinants of hypertension with AOR [95% CI] were obesity: 2.82 [1.43, 5.57], sedentary activity of ≥4hrs/day: 1.75 [1.10, 2.79], higher stress score: 1.05 [1.01, 1.10], serum creatinine above 1.1 mg/dl: 2.35 [1.13, 4.91], age: 1.05 [1.02, 1.08], being government employee as compared to private workers: 2.18 [1.06, 4.50] and family history of hypertension: 2.11 [1.26, 3.54]. Further, interaction of diabetes duration with insulin use: 1.03 [1.01, 1.07] was also a significant predictor of HTN among DM patients.

CONCLUSION

The finding calls for interventions for mitigating these determinants. Further research is needed to examine the interaction between diabetes duration and insulin use.

Impact of Valvulo-Arterial Impedance on Long-Term Quality of Life and Exercise Performance After Transcatheter Aortic Valve Replacement

BACKGROUND

In aortic stenosis, valvulo-arterial impedance (Zva) estimates the overall left ventricular afterload (valve and arterial component). We investigated the association of Zva (≥5 versus <5 mm Hg mL^-1 m^-2) on quality of life (QOL) and exercise performance (EP) ≥1 year after transcatheter aortic valve replacement (TAVR).

METHODS

The study population consists of 250 TAVR patients in whom baseline Zva and follow-up QOL was prospectively assessed using EuroQOL-5-dimensions instruments; EP was assessed in 192 patients who survived ≥1 year after TAVR using questionnaires related to daily activities. In 124 patients, Zva at 1-year was also available and was used to study the change in Zva (baseline to 1 year) on QOL/EP.

RESULTS

Elevated baseline Zva was present in 125 patients (50%). At a median of 28 (IQR, 17-40) months, patients with elevated baseline Zva were more limited in mobility (88% versus 71%; P=0.004), self-care (40% versus 25%; P=0.019), and independent daily activities (taking a shower: 53% versus 38%, P=0.030; walking 100 meter: 76% versus 54%, P=0.001; and walking stairs: 74% versus 54%, P=0.011). By multivariable analysis, elevated Zva predicted unfavorable QOL (lower EuroQOL-5-dimensions-Utility Index, odds ratio, 1.98; CI, 1.15-3.41) and unfavorable EP (any limitation in ≥3 daily activities, odds ratio, 2.55; CI, 1.41-4.62). After TAVR, the proportion of patients with elevated Zva fell from 50% to 21% and remained 21% at 1 year and was found to be associated with more limitations in mobility, self-care, and daily activities compared with patients with Zva <5 mm Hg mL^-1 m^-2.

CONCLUSIONS

Elevated Zva was seen in half of patients and predicted unfavorable long-term QOL and EP. At 1 year after TAVR, the prevalence of elevated Zva was 21% but remained associated with poor QOL/EP.

Senescent cells: a therapeutic target for cardiovascular disease

Cellular senescence, a major tumor-suppressive cell fate, has emerged from humble beginnings as an in vitro phenomenon into recognition as a fundamental mechanism of aging. In the process, senescent cells have attracted attention as a therapeutic target for age-related diseases, including cardiovascular disease (CVD), the leading cause of morbidity and mortality in the elderly. Given the aging global population and the inadequacy of current medical management, attenuating the health care burden of CVD would be transformative to clinical practice. Here, we review the evidence that cellular senescence drives CVD in a bimodal fashion by both priming the aged cardiovascular system for disease and driving established disease forward. Hence, the growing field of senotherapy (neutralizing senescent cells for therapeutic benefit) is poised to contribute to both prevention and treatment of CVD.

25-hydroxyvitamin D and parathyroid hormone levels do not predict changes in carotid arterial stiffness: the Multi-Ethnic Study of Atherosclerosis

OBJECTIVE

To evaluate the impact of vitamin D and parathyroid hormone (PTH) on longitudinal changes in arterial stiffness.

APPROACH AND RESULTS

Distensibility coefficient and Young's elastic modulus of the right common carotid artery were evaluated at baseline and after a mean (SD) of 9.4 (0.5) years in 2580 Multi-Ethnic Study of Atherosclerosis (MESA) participants. Cross-sectional and longitudinal associations were evaluated using multivariable linear regression and analysis of covariance. At baseline, participants were 60.1 (9.4) years old (54% female; 26% black, 20% Hispanic, 14% Chinese). Mean annualized 25(OH)D was <20 ng/dL in 816 participants, and PTH was >65 pg/dL in 285 participants. In cross-sectional analyses, low 25(OH)D (<20 ng/mL) was not associated with stiffer arteries after adjustment for cardiovascular disease risk factors (P>0.4). PTH >65 pg/mL was associated with stiffer arteries after adjustment for cardiovascular disease risk factors, other than systolic blood pressure (distensibility coefficient: β=-2.4×10(-4) mm Hg(-1), P=0.003; Young's elastic modulus: β=166 mm Hg, P=0.01); however, after adjustment for systolic blood pressure, these associations no longer were statistically significant. Longitudinal arterial stiffening was associated with older age (P<0.0001), higher systolic blood pressure (P<0.008), and use of antihypertensive medications (P<0.006), but not with 25(OH)D or PTH (both P>0.1).

CONCLUSIONS

Carotid arterial stiffness is not associated with low 25(OH)D concentrations. Cross-sectional associations between arterial stiffness and high PTH were attenuated by systolic blood pressure. After nearly a decade of follow-up, neither baseline PTH nor 25(OH)D concentrations were associated with progression of carotid arterial stiffness.

β-Blockers

Objective: To review the pharmacology, pharmacokinetics, and pharmacodynamic properties of commonly used β-blockers (atenolol, carvedilol, metoprolol succinate, metoprolol tartrate, and nebivolol). Data Sources: A MEDLINE literature search (1966-May 2013) was performed using the following key terms: hypertension, β-blockers, atenolol, carvedilol, metoprolol tartrate, metoprolol succinate, nebivolol, pharmacology, pharmacodynamics, pharmacokinetics, blood pressure, metabolic, lipid, central aortic pressure, diabetes, and insulin resistance. References from publications reviewed were included. Study Selection and Data Extraction: English-language articles identified were reviewed. Animal studies and studies in patients for a primary diagnosis of coronary artery disease were excluded. Data Synthesis: β-Blockers are no longer recommended first-line therapy for primary hypertension, based on data showing that β-blockers are inferior to other antihypertensives and no better than placebo, in spite of provision of blood pressure reduction. Because atenolol is the β-blocker used in 75% of these studies, uncertainty about widespread application to all β-blockers exists. Different pharmacological and physiological properties, both within β-blockers and compared with other antihypertensives, may explain divergent effects. Evidence shows that β-blockers have a truncated effect on central aortic pressure, an independent predictor of cardiovascular events, compared with other antihypertensive classes; differences within the class may exist, but the evidence is inconclusive. Metabolic effects differ within the β-blocker class, with evidence that carvedilol causes less metabolic dysregulation. Conclusion: Emerging evidence reveals physiological differences within the β-blocker class and in comparison to other antihypertensives. These differences provide insight into the diverse clinical effects β-blockers provide in cardiovascular disease.

Longitudinal effects of a decade of aging on carotid artery stiffness: the multiethnic study of atherosclerosis

BACKGROUND AND PURPOSE

Arterial stiffening is associated with hypertension, stroke, and cognitive decline; however, the effects of aging and cardiovascular disease risk factors on carotid artery stiffening have not been assessed prospectively in a large multiethnic longitudinal study.

METHODS

Distensibility coefficient and the Young's elastic modulus (YEM) of the right common carotid artery were calculated at baseline and after a mean of 9.4 (standard deviation [SD], 0.5) years in 2650 participants. Effects of age and cardiovascular disease risk factors were evaluated by multivariable mixed regression and ANCOVA models.

RESULTS

At baseline, participants were 59.9 (SD, 9.4) years old (53% women; 25% black, 22% Hispanic, 14% Chinese). YEM increased from 1581 (SD, 927) to 1749 (SD, 1306) mm Hg (P<0.0001), and distensibility coefficient decreased from 3.1 (SD, 1.3) to 2.7 (SD, 1.1)×10(-3) mm Hg(-1) (P<0.001), indicating progressive arterial stiffening. YEM increased more among participants who were aged>75 years old at baseline (P<0.0001). In multivariable analyses, older age and less education independently predicted worsening YEM and distensibility coefficient. Stopping antihypertensive medication during the study period predicted more severe worsening of YEM (β=360.2 mm Hg; P=0.008). Starting antihypertensive medication after examination 1 was predictive of improvements in distensibility coefficient (β=1.1×10(-4) mm Hg(-1); P=0.024).

CONCLUSIONS

Arterial stiffening accelerates with advanced age. Older individuals experience greater increases in YEM than do younger adults, even after considering the effects of traditional risk factors. Treating hypertension may slow the progressive decline in carotid artery distensibility observed with aging and improve cerebrovascular health.

Large arteries and the kidney

In subjects with chronic renal disease, high systolic blood pressure (SBP) is the most modifiable cardiovascular (CV) risk factor that enables prevention of the progression of chronic kidney disease renal failure and the occurrence of CV events. Although large-artery stiffness and wave reflections are the principal hemodynamic determinants of SBP, their precise role in the progression of chronic renal disease has been poorly investigated. However, in subjects with mild to severe renal insufficiency, increased arterial stiffness and reduced creatinine clearance are closely related, independently of age; mean arterial pressure level; and presence of other traditional risk factors, including atherosclerotic plaques. Through inflammatory mechanisms, as well as through the development of arterial calcifications (including microscopic) and sodium-related alterations in extracellular matrix composition, arterial stiffness is associated with significant SBP and increased pulse pressure (PP). In the presence of renal dysfunction, frequently observed in elderly hypertensive or diabetic subjects, or even in some living donors, the resulting increase in PP may be transmitted toward and across glomeruli, even when peripheral blood pressure values are maintained. This alteration alone may initiate glomerulosclerosis and/or tubulointerstitial damage, eventually leading to CV events. In subjects with end-stage renal disease and high CV risk, pharmacological modulation of the renin-angiotensin system has been shown to prevent independently such complications.

An emerging concept of vascular salt sensitivity

Excessive amounts of salt in food, as usually consumed worldwide, affect the vascular system, leading to high blood pressure and premature disabilities. Salt entering the vascular bed after a salty meal is transiently bound to the endothelial glycocalyx, a negatively charged biopolymer lining the inner surface of the blood vessels. This barrier protects the endothelium against salt overload. A poorly-developed glycocalyx increases the salt permeability of the vascular system and the amount of salt being deposited in the body, which affects organ function. A simple test system is now available that evaluates vascular salt sensitivity in humans and identifies individuals who are at risk of salt-induced hypertension. This short review aims to discuss how the underlying basic research can be translated into medical practice and, thus, meaningful health outcomes.

Sex-specific association of age with carotid artery distensibility: multi-ethnic study of atherosclerosis

BACKGROUND

Older women have a higher prevalence of systolic hypertension than do men; however, whether or not this relates to arterial properties, such as distensibility coefficient (DC), is not known. We examined whether the association of carotid artery DC with age differed by sex in the Multi-Ethnic Study of Atherosclerosis (MESA).

METHODS

B-mode ultrasound-measured carotid diameters and brachial pressures were obtained from 6359 participants (53% female, 38% white, 12% Chinese, 27% black, 22% Hispanic, aged 45-85 years) of the MESA baseline examination. The within-individual slopes of 2log(diameter) vs. blood pressure fit using mixed models (MM) are interpreted as the DC, and interaction terms are interpreted as differences in DC. The MM calculation allows for correction of the confounding caused by the association of age, sex, and race with blood pressure, the denominator in the calculation of DC.

RESULTS

DC was associated with age, sex, and race (all p<0.001). Women had a greater age-related lowering of DC compared to men (2.52×10(-5) vs. 2.16×10(-5)/mm Hg lower DC per year of age, p=0.006). Mean diameter of carotid arteries was greater with age (p<0.001); this association also was significantly stronger in women compared to men (0.24% vs. 0.14% larger mean carotid diameter per year of age, p<0.001).

CONCLUSIONS

Greater stiffening and enlargement of arteries are seen in older women compared to older men. This implies that the afterload on the heart of older women is likely to be greater than that among older men.

Effects of Azelnidipine plus OlmesaRTAn versus amlodipine plus olmesartan on central blood pressure and left ventricular mass index: the AORTA study

PURPOSE

The aim of this study was to compare the effects of olmesartan combined with either azelnidipine or amlodipine on central blood pressure (CBP) and left ventricular mass index (LVMI) in hypertensive patients.

PATIENT AND METHODS

Patients with brachial systolic BP ≥ 140 mmHg and/or diastolic BP ≥ 90 mmHg received olmesartan monotherapy (20 mg daily) for 12 weeks. The patients were then randomly assigned to fixed-dose add-on therapy with azelnidipine (16 mg daily) or amlodipine (5 mg daily) (25 patients/group) for a further 24 weeks. CBP and LVMI were measured at baseline and at the end of the study.

RESULTS

Baseline characteristics were similar in both groups. The decrease in brachial BP was similar in both groups. CBP and LVMI decreased significantly in both groups (both, P < 0.001). However, the decreases in CBP and LVMI were significantly greater with olmesartan/azelnidipine than with olmesartan/amlodipine (CBP, P < 0.001; LVMI, P = 0.002).

CONCLUSIONS

These findings indicate that olmesartan/azelnidipine had greater effects on CBP and LVMI than did olmesartan/amlodipine, even though the reduction in brachial BP was similar in both groups. These differential effects on CBP and LVMI may have important implications for cardiovascular risk reduction.

High urinary sodium is associated with increased carotid intima-media thickness in normotensive overweight and obese adults

BACKGROUND

Increased dietary sodium has been reported to increase cardiovascular disease (CVD) risk, perhaps through blood pressure (BP)-independent vascular remodeling. Carotid intima-media thickness (IMT) is an accepted measure of structural vascular remodeling and a strong predictor of CVD. This study aimed to determine whether urinary sodium is positively associated with carotid IMT in normotensive overweight and obese adults.

METHODS

We evaluated baseline data from 258 participants in the Slow Adverse Vascular Effects (SAVE) clinical trial. Urinary sodium was measured from one 24-h urine collection from each individual. Carotid IMT was measured using high-resolution B-mode ultrasonography. Participants were categorized into quartiles of urinary sodium.

RESULTS

There was a significant positive trend with greater IMT associated with increasing urinary sodium quartile in univariate linear regression (P = 0.047). This trend was significant when adjusting for age, sex, race, and systolic BP (SBP) (P = 0.03) as well as in a fully adjusted model (P = 0.04). In pairwise comparisons, the highest urinary sodium quartile had a significantly greater mean IMT (0.62 mm) than the lowest urinary sodium quartile (0.59 mm) after adjustment for age, sex, race, and SBP (P = 0.04). This comparison lost significance after the addition of BMI.

CONCLUSIONS

In our community-based sample of normotensive overweight and obese adults, we observed a significant positive trend in carotid IMT with increasing quartile of urinary sodium. If the ongoing clinical trial confirms this relationship between sodium and carotid IMT, it would lend support to efforts to decrease sodium intake in overweight and obese individuals.

Use of medicines by persons with disabilities in São Paulo state areas, Southeastern Brazil

OBJECTIVE

To analyze the use of medicines and the main therapeutic groups consumed by persons with physical, hearing and visual disabilities.

METHODS

A cross-sectional study was performed, where data from the 2002 Inquérito Multicêntrico de Saúde no Estado de São Paulo (ISA-SP - São Paulo State Multicenter Health Survey), as well as the 2003 Inquérito de Saúde no Município de São Paulo (ISA-Capital - City of São Paulo Health Survey), Southeastern Brazil, were analyzed. Respondents who reported having disabilities were studied, according to variables that comprise the database: geographic area, gender, income, age group, ethnic group, use of medicines and types of drugs consumed.

RESULTS

The percentage of use of drugs by persons with disabilities was 62.8% among the visually impaired; 60.2% among the hearing impaired; and 70.1% among the persons with physical disabilities. Individuals with physical disabilities consumed 20% more medications than non-disabled ones. Among persons with visual disabilities, the most frequently consumed drugs were diuretics, agents of the renin-angiotensin system and analgesics. Persons with hearing disabilities used more analgesics and agents of the renin-angiotensin system. Among those with physical disabilities, analgesics, antithrombotics and agents of the renin-angiotensin system were the most frequently consumed medicines.

CONCLUSIONS

There was a greater use of medicines among persons with disabilities than non-disabled ones. Persons with physical disabilities were those who most consumed medicines, followed by the visually impaired and the hearing impaired.

Ménage à trois: aldosterone, sodium and nitric oxide in vascular endothelium

Aldosterone, a mineralocorticoid hormone mainly synthesized in the adrenal cortex, has been recognized to be a regulator of cell mechanics. Recent data from a number of laboratories implicate that, besides kidney, the cardiovascular system is an important target for aldosterone. In the endothelium, it promotes the expression of epithelial sodium channels (ENaC) and modifies the morphology of cells in terms of mechanical stiffness, surface area and volume. Additionally, it renders the cells highly sensitive to small changes in extracellular sodium and potassium. In this context, the time course of aldosterone action is pivotal. In the fast (seconds to minutes), non-genomic signalling pathway vascular endothelial cells respond to aldosterone with transient swelling, softening and insertion of ENaC in the apical plasma membrane. In parallel, nitric oxide (NO) is released from the cells. In the long-term (hours), aldosterone has opposite effects: The mechanical stiffness increases, the cells shrink and NO production decreases. This leads to the conclusion that both the physiology and pathophysiology of aldosterone action in the vascular endothelium are closely related. Aldosterone, at concentrations in the physiological range and over limited time periods can stabilize blood pressure and regulate tissue perfusion while chronically high concentrations of this hormone over extended time periods impair sodium homeostasis promoting endothelial dysfunction and the development of tissue fibrosis.

Relation between the estimated glomerular filtration rate and pulse wave velocity in Japanese

OBJECTIVE

We investigated the link between renal function as evaluated by estimated glomerular filtration rate (eGFR) and pulse wave velocity (PWV) in Japanese without medications.

METHODS

A total of 1,244 Japanese subjects, aged 20-79 years, were recruited in a cross-sectional clinical investigation study. They received no medications. eGFR was calculated using serum creatinine (Cr), age and sex. Peripheral arterial stiffness was evaluated by brachial-ankle PWV (baPWV).

RESULTS

eGFR and baPWV were significantly correlated with age. eGFR was negatively correlated with baPWV (men: r=-0.308, p<0.0001, women: r=-0.293, p<0.0001). Twenty-six men (5.6%) and 35 women (4.5%) were diagnosed as reduced eGFR (eGFR <60 mL/min/1.73 m(2)). We compared clinical parameters between subjects with reduced eGFR (Group R) and without such reduction (Group N). baPWV in Group R was significantly higher than that in Group N even after adjusting for age. In women, systolic blood pressure in Group R was also significantly higher than that in Group N.

CONCLUSION

eGFR was closely associated with peripheral arterial stiffness in Japanese.

The macrocirculation and microcirculation of hypertension

Changes in vascular structure that accompany hypertension may contribute to hypertensive end-organ damage. Both the macrovascular and microvascular levels should be considered, as interactions between them are believed to be critically important. Regarding the macrocirculation, the article first reviews basic concepts of vascular biomechanics, such as arterial compliance, arterial distensibility, and stress-strain relationships of arterial wall material, and then reviews how hypertension affects the properties of conduit arteries, particularly examining evidence that it accelerates the progressive stiffening that normally occurs with advancing age. High arterial stiffness may increase central systolic and pulse pressure by two different mechanisms: 1) Abnormally high pulse wave velocity may cause pressure waves reflected in the periphery to reach the central aorta in systole, thus augmenting systolic pressure; 2) In the elderly, the interaction of the forward pressure wave with high arterial stiffness is mostly responsible for abnormally high pulse pressure. At the microvascular level, hypertensive disease is characterized by inward eutrophic or hypertrophic arteriolar remodeling and capillary rarefaction. These abnormalities may depend in part on the abnormal transmission of highly pulsatile blood pressure into microvascular networks, especially in highly perfused organs with low vascular resistance, such as the kidney, heart, and brain, where it contributes to hypertensive end-organ damage.

Aldosterone-induced endothelial dysfunction of rat aorta: role of poly(ADP-ribose) activation

Introduction. The aim of this study was to investigate whether activation of the nuclear enzyme poly(ADP-ribose) polymerase (PARP) contributes to the development of aldosterone-induced endothelial dysfunction and treatment with the potent PARP inhibitor 1,5-isoquinolinediol (3 mg/kg/day, i.p.) could prevent endothelial dysfunction caused by aldosterone.

Methods. Infusion of subpressor doses of aldosterone with subcutaneously implanted mini-osmotic pumps (0.05 mg/kg/day) to rats for 21 days induced the development of endothelial dysfunction. In order to evaluate endothelial function, isometric tension studies were performed in response to acetylcholine and sodium nitroprusside.Additionally, PAR (the end product of activated PARP) and PARP-1 expressions in the endothelium of thoracic aortas were evaluated by immunohistochemistry.

Results. There was a significant loss of endothelium-dependent vasodilatation in response to acetylcholine in aldosterone-infused rats. In animals treated with 1,5-isoquinolinediol, the effect of aldosterone on vascular responsiveness was less than the untreated groups. Immunohistochemical studies demonstrated that aldosterone administration increased PAR and PARP-1 expressions in the endothelium of thoracic aortas, whereas PARP inhibition decreased their expressions to control levels.

Conclusion. Our results indicate that PARP activation in the vascular system may be a contributory factor to the impaired endothelial function associated with aldosterone administration.

Effects of age, genes, and pulse pressure on executive functions in healthy adults

Executive functions (EF) evidence significant age-related declines, but the mechanisms underpinning those changes are unclear. In this study, we focus on two potential sources of variation: a physiological indicator of vascular health, and genetic variants related to vascular functions. In a sample of healthy adults (n=158, ages 18-81), we examine the effects of age, pulse pressure, and two polymorphisms (comt val158met and ace insertion/deletion) on working memory and cognitive flexibility. Results indicate that in addition to often-replicated age differences, the alleles of two polymorphisms that promote vasoconstriction (comt val and ace D) and reduced availability of dopamine in neocortical synapses (comt val), negatively impact virtually all aspects of EF tasks that involve working memory. In some cases, suppression of cognitive performance is limited to men or necessitates a combination of both risk-associated alleles. After accounting for genetic and age-related variation, pulse pressure had no additional effect on EF. These findings suggest that in healthy adults, the effects of genetic risk factors significantly modulate the course of cognitive aging.

Renin-angiotensin system revisited

New components and functions of the renin-angiotensin system (RAS) are still being unravelled. The classical RAS as it looked in the middle 1970s consisted of circulating renin, acting on angiotensinogen to produce angiotensin I, which in turn was converted into angiotensin II (Ang II) by angiotensin-converting enzyme (ACE). Ang II, still considered the main effector of RAS was believed to act only as a circulating hormone via angiotensin receptors, AT1 and AT2. Since then, an expanded view of RAS has gradually emerged. Local tissue RAS systems have been identified in most organs. Recently, evidence for an intracellular RAS has been reported. The new expanded view of RAS therefore covers both endocrine, paracrine and intracrine functions. Other peptides of RAS have been shown to have biological actions; angiotensin 2-8 heptapeptide (Ang III) has actions similar to those of Ang II. Further, the angiotensin 3-8 hexapeptide (Ang IV) exerts its actions via insulin-regulated amino peptidase receptors. Finally, angiotensin 1-7 (Ang 1-7) acts via mas receptors. The discovery of another ACE2 was an important complement to this picture. The recent discovery of renin receptors has made our view of RAS unexpectedly complex and multilayered. The importance of RAS in cardiovascular disease has been demonstrated by the clinical benefits of ACE inhibitors and AT1 receptor blockers. Great expectations are now generated by the introduction of renin inhibitors. Indeed, RAS regulates much more and diverse physiological functions than previously believed.

Predicting arterial stiffness with ambulatory blood pressure: an 11-year follow-up

No prospective data have been published on whether ambulatory blood pressure (BP) works better than casual measurements in predicting arterial stiffness. This study with 11-year follow-up was launched to evaluate the usefulness of ambulatory intra-arterial BP in predicting pulse wave velocity (PWV). Ninety-seven previously healthy men were recruited from a routine physical check-up at baseline. BP was measured with standard cuff and intra-arterial ambulatory methods. Sixty-seven subjects with no antihypertensive medication were enrolled for a visit after a follow-up of 11 years. Arterial stiffness was estimated with PWV derived with impedance cardiography. Ambulatory 24-h systolic blood pressure (SBP) (r = 0.30, P = 0.01), 24-h mean arterial pressure (r = 0.27, P = 0.03), 24-h pulse pressure (r = 0.27, P = 0.03) and daytime SBP (r = 0.26, P = 0.03) were the best BP variables in predicting future PWV. Casual BP values did not bear significant correlations with future PWV. In hierarchical regression analysis, the best predictive value for future PWV was achieved with the model including ambulatory 24-h SBP, smoking (number of cigarettes) and age (adjusted R(2) = 0.26). In conclusion, to our knowledge, this is the only prospective follow-up study to show that ambulatory BP is superior to casual BP measurement in predicting future PWV.

Association between wasted pressure effort and left ventricular hypertrophy in hypertension: influence of arterial wave reflection

BACKGROUND

Wave reflection during the systole increases left ventricular (LV) pressure, tension-time index (TTI) and myocardial oxygen requirement. The purpose of this study was to extract that component of extra myocardial oxygen requirement that is due to early systolic wave reflection, define it as wasted effort (DeltaE(w)), and examine its relationship to LV hypertrophy (LVH).

METHODS

Radial artery pressure waveforms were recorded using applanation tonometry and central aortic waveforms generated in 98 patients with untreated hypertension. Aortic augmentation index (AI(a)), wave reflection amplitude (i.e., aortic augmented pressure (AG)) and systolic duration (ED-Tr), ejection duration (ED) and round-trip travel time of the pressure wave (Tr) were calculated from the aortic waveform, and DeltaE(w) estimated as 2.09 AG (ED-Tr). Carotid-femoral pulse wave velocity (PWV(e)) was also measured and LV mass index (LVMI) determined by echocardiography.

RESULTS

DeltaE(w) was significantly correlated with age, body height, and LVMI. Women had greater DeltaE(w) than men. The correlation between DeltaE(w) and LVMI was independent of age, gender and body height (P = 0.003). Patients with LVH (LVH (+) group) showed greater DeltaE(w) than patients without LVH (LVH (-) group) (P = 0.003), and this difference remained significant when adjusted for confounding factors. Also, AI(a) and AG were higher in the LVH (+) than in the LVH (-) group (both P < 0.01). In contrast, PWV(e) was not different between the groups, and Tr showed only a marginal difference (P = 0.07).

CONCLUSIONS

DeltaE(w) appears to be directly and positively associated with LVH in untreated hypertensive patients. The amplitude and duration of the reflected wave, rather than its travel time, are probably responsible for this association.

An association between decreased estimated glomerular filtration rate and arterial stiffness

OBJECTIVE

Chronic kidney disease (CKD) is a major public health problem, but there is controversy over whether or not CKD is an independent risk factor for peripheral arterial stiffness in community residents.

PATIENTS AND METHODS

We randomly recruited 107 men, aged 68+/-9 (mean +/- standard deviation) years, and 203 women, aged 67+/-7 years during their annual health examination in a single community. Study subjects did not have a clinical history of cerebrovascular disease or current neurological abnormalities. Peripheral arterial stiffness was evaluated by mean pulse wave velocity (PWV) determined at three points: from heart to the carotid artery, to the brachial artery, and to the ankle, and CKD was evaluated by estimated glomerular filtration rate (eGFR) using the Modification of Diet in Renal Disease Study Group equation.

RESULTS

Estimated GFR was significantly correlated with mean PWV (r=-0.317, p<0.001). Stepwise multiple linear regression analysis using mean PWV as an objective variable, adjusted by explanatory variables, showed that eGFR (beta,-0.171; p<0.001) significantly contributed to mean PWV, along with age, body mass index, systolic blood pressure, diastolic blood pressure, and antihypertensive drug use, and improved multiple coefficient of determination in the model.

CONCLUSION

Decreased eGFR is associated with an increased risk of arterial stiffness in community residents.

Vascular microarray profiling in two models of hypertension identifies caveolin-1, Rgs2 and Rgs5 as antihypertensive targets

BACKGROUND

Hypertension is a complex disease with many contributory genetic and environmental factors. We aimed to identify common targets for therapy by gene expression profiling of a resistance artery taken from animals representing two different models of hypertension. We studied gene expression and morphology of a saphenous artery branch in normotensive WKY rats, spontaneously hypertensive rats (SHR) and adrenocorticotropic hormone (ACTH)-induced hypertensive rats.

RESULTS

Differential remodeling of arteries occurred in SHR and ACTH-treated rats, involving changes in both smooth muscle and endothelium. Increased expression of smooth muscle cell growth promoters and decreased expression of growth suppressors confirmed smooth muscle cell proliferation in SHR but not in ACTH. Differential gene expression between arteries from the two hypertensive models extended to the renin-angiotensin system, MAP kinase pathways, mitochondrial activity, lipid metabolism, extracellular matrix and calcium handling. In contrast, arteries from both hypertensive models exhibited significant increases in caveolin-1 expression and decreases in the regulators of G-protein signalling, Rgs2 and Rgs5. Increased protein expression of caveolin-1 and increased incidence of caveolae was found in both smooth muscle and endothelial cells of arteries from both hypertensive models.

CONCLUSION

We conclude that the majority of differences in gene expression found in the saphenous artery taken from rats with two different forms of hypertension reflect distinctive morphological and physiological alterations. However, changes in common to caveolin-1 expression and G protein signalling, through attenuation of Rgs2 and Rgs5, may contribute to hypertension through augmentation of vasoconstrictor pathways and provide potential targets for common drug development.

Plasma sodium stiffens vascular endothelium and reduces nitric oxide release

Dietary salt plays a major role in the regulation of blood pressure, and the mineralocorticoid hormone aldosterone controls salt homeostasis and extracellular volume. Recent observations suggest that a small increase in plasma sodium concentration may contribute to the pressor response of dietary salt. Because endothelial cells are (i) sensitive to aldosterone, (ii) in physical contact with plasma sodium, and (iii) crucial regulators of vascular tone, we tested whether acute changes in plasma sodium concentration, within the physiological range, can alter the physical properties of endothelial cells. The tip of an atomic force microscope was used as a nanosensor to measure stiffness of living endothelial cells incubated for 3 days in a culture medium containing aldosterone at a physiological concentration (0.45 nM). Endothelial cell stiffness was unaffected by acute changes in sodium concentration <135 mM but rose steeply between 135 and 145 mM. The increase in stiffness occurred within minutes. Lack of aldosterone in the culture medium or treatment with the epithelial sodium channel inhibitor amiloride prevented this response. Nitric oxide formation was found down-regulated in cells cultured in aldosterone-containing high sodium medium. The results suggest that changes in plasma sodium concentration per se may affect endothelial function and thus control vascular tone.

Paradoxical role of angiotensin II type 2 receptors in resistance arteries of old rats

The role of angiotensin II type 2 receptors (AT2Rs) remains a matter of controversy. Its vasodilatory and antitrophic properties are well accepted. Nevertheless, in hypertensive rats, AT2R stimulation induces a vasoconstriction counteracting flow-mediated dilation (FMD). This contraction is reversed by hydralazine. Because FMD is also decreased in aging, another risk factor for cardiovascular diseases, we hypothesized that AT2R function might be altered in old-rat resistance arteries. Mesenteric resistance arteries (250 mum in diameter) were isolated from old (24 months) and control (4 months) rats receiving hydralazine (16 mg/kg per day; 2 weeks) or water. FMD, NO-mediated dilation, and endothelial NO synthase expression were lower in old versus control rats. AT2R blockade improved FMD in old rats, suggesting that AT2R stimulation produced vasoconstriction. AT2R expression was higher in old rats and mainly located in the smooth muscle layer. In old rats, AT2R stimulation induced endothelium-independent contraction, which was suppressed by the antioxidant Tempol. Reactive oxygen species level was higher in old-rat arteries than in controls. Hydralazine improved FMD and NO-dependent dilation in old rats without change in AT2R expression and location. In old rats treated with hydralazine, reactive oxygen species level was reduced in endothelial and smooth muscle cells, and AT2R-dependent contraction was abolished. Thus, AT2R stimulation induced vasoconstriction through activation of reactive oxygen species production, contributing to decrease FMD in old-rat resistance arteries. Hydralazine suppressed AT2R-dependent reactive oxygen species production and AT2R-dependent contraction, improving FMD. Importantly, endothelial alterations in aging were reversible. These findings are important to consider in the choice of vasoactive drugs in aging.

Blood pressure and ageing

Isolated systolic hypertension, an elevation in systolic but not diastolic pressure, is the most prevalent type of hypertension in those aged 50 or over, occurring either de novo or as a development after a long period of systolic-diastolic hypertension with or without treatment. The increase in blood pressure with age is mostly associated with structural changes in the arteries and especially with large artery stiffness. It is known from various studies that rising blood pressure is associated with increased cardiovascular risk. In the elderly, the most powerful predictor of risk is increased pulse pressure due to decreased diastolic and increased systolic blood pressure. All evidence indicates that treating the elderly hypertensive patient will reduce the risk of cardiovascular events. However, there is no evidence yet for the very elderly. This population is particularly susceptible to side effects of treatments and the reduction of blood pressure, although reducing the risk of cardiovascular events such as stroke, may result in increased mortality.

Is the vascular endothelium under the control of aldosterone? Facts and hypothesis

Fluid and electrolyte balance in the human organism is controlled by aldosterone, a mineralocorticoid hormone of the suprarenal glands. The major target cells are localized in the kidney where the hormone controls transepithelial salt transport. Over the past few years, evidence has been accumulated that cells of the cardiovascular system are also targeted by the hormone. As an example, endothelial cells resemble similar mechanisms triggered by aldosterone as shown for the kidney. Although the pathological alterations induced by aldosterone excess are obvious, the physiological changes are largely unknown. On the basis of recent experiments, using atomic force microscopy as an imaging tool and a mechanical sensor, I present a hypothesis on the physiological role of aldosterone in endothelial function and its potential implications in the control of blood pressure.

Insulin resistance is associated with arterial stiffness in nondiabetic hypertensives independent of metabolic status

We sought to determine whether insulin resistance (IR) is related to arterial stiffness in nondiabetic hypertensive patients, independent of metabolic status and gender. IR has been associated with increased arterial stiffness in patients with diabetes. In nondiabetic hypertensive patients, the correlation between IR and arterial stiffness has yet to be investigated. We enrolled 284 nondiabetic patients who were being treated for hypertension. At the time of enrollment, the patients underwent a baseline laboratory assessment including homeostatic model assessment (HOMA) IR index and pulse wave velocity (PWV). The HOMA IR index is used as a marker of IR, and brachial to ankle PWV (baPWV) was used as a marker of arterial stiffness. Of the 284 study subjects, 121 were classified as having metabolic syndrome. The patients with metabolic syndrome were older than the non-metabolic syndrome patients (55.4+/-10.7 vs. 52.1+/-11.6 years, p=0.013), but there was no gender difference between the two groups. The average baPWV was significantly higher in the patients with metabolic syndrome (1,506+/-235 vs. 1,435+/-211 cm/s, p=0.009). The HOMA index was independently associated with an increase in arterial stiffness (r=0.548, p<0.001) after controlling for age, systolic blood pressure (SBP), heart rate, medication and gender. The independent association of HOMA with arterial stiffness was demonstrated in subgroup analysis, regardless of the metabolic status and gender. In conclusion, increased IR was associated with arterial stiffness, independent of age, baseline SBP, gender and heart rate. This independent association of IR was demonstrated regardless of gender and metabolic status.

Arterial aging: is it an immutable cardiovascular risk factor?

Age is the dominant risk factor for cardiovascular diseases. However, until recently, convincing mechanistic or molecular explanations for the increased cardiovascular risks conferred by aging have been elusive. Aging is associated with alterations in a number of structural and functional properties of large arteries, including diameter, wall thickness, wall stiffness, and endothelial function. Emerging evidence indicates that these age-associated changes are also accelerated in the presence of cardiovascular diseases, and that these changes are themselves risk factors for the appearance or progression of these diseases. In this review, the evidence demonstrating that arterial aging is accelerated in cardiovascular diseases and that accelerated arterial aging is a risk factor for adverse cardiovascular outcomes is briefly reviewed, and selected advances in vascular biology that provide insights into the mechanisms that may underlie the increased risks conferred by arterial aging are summarized. Remarkably, a host of biochemical, enzymatic, and cellular alterations that are operative in accelerated arterial aging have also been implicated in the pathogenesis and progression of arterial diseases. These vascular alterations are thus putative candidates that could be targeted by interventions aimed at attenuating arterial aging, similar to the lifestyle and pharmacological interventions that have already been proven effective. Therefore, the notion that aging is a chronological process and that its risky components cannot be modulated is no longer tenable. It is our hope that a greater appreciation of the links between arterial aging and cardiovascular diseases will stimulate further investigation into strategies aimed at preventing or retarding arterial aging.