Relationships between left ventricular mass and the renin-angiotensin system, catecholamines, insulin and leptin

Prevalence of left ventricular hypertrophy in children and young people with primary hypertension: Meta-analysis and meta-regression

BACKGROUND

Left ventricular hypertrophy (LVH) is the main marker of HMOD in children and young people (CYP). We aimed to assess the prevalence of LVH and its determinants in CYP with primary hypertension (PH).

METHODS

A meta-analysis of prevalence was performed. A literature search of articles reporting LVH in CYP with PH was conducted in Medline, Embase, and Cochrane databases. Studies with a primary focus on CYP (up to 21 years) with PH were included. Meta-regression was used to analyze factors explaining observed heterogeneity.

RESULTS

The search yielded a total of 2,200 articles, 153 of those underwent full-text review, and 47 reports were included. The reports evaluated 51 study cohorts including 5,622 individuals, 73% male subjects, and a mean age of 13.6 years. LVH was defined as left ventricle mass index (LVMI) ≥ 95th percentile in 22 (47%), fixed cut-off ≥38.6 g/m2.7 in eight (17%), sex-specific fixed cut-off values in six (13%), and miscellaneously in others. The overall prevalence of LVH was 30.5% (95% CI 27.2-33.9), while heterogeneity was high (I 2 = 84%). Subgroup analysis including 1,393 individuals (76% male subjects, mean age 14.7 years) from pediatric hypertension specialty clinics and LVH defined as LVMI ≥95th percentile only (19 study cohorts from 18 studies), reported prevalence of LVH at 29.9% (95% CI 23.9 to 36.3), and high heterogeneity (I 2 = 84%). Two studies involving patients identified through community screening (n = 1,234) reported lower LVH prevalence (21.5%). In the meta-regression, only body mass index (BMI) z-score was significantly associated with LVH prevalence (estimate 0.23, 95% CI 0.08-0.39, p = 0.004) and accounted for 41% of observed heterogeneity, but not age, male percentage, BMI, or waist circumference z-score. The predominant LVH phenotype was eccentric LVH in patients from specialty clinics (prevalence of 22% in seven studies with 779 participants) and one community screening study reported the predominance of concentric LVH (12%).

CONCLUSION

Left ventricular hypertrophy is evident in at least one-fifth of children and young adults with PH and in nearly a third of those referred to specialty clinics with a predominant eccentric LVH pattern in the latter. Increased BMI is the most significant risk association for LVH in hypertensive youth.

Cardiovascular Outcomes in Kidney Transplant Recipients With ADPKD

Introduction

Cardiovascular disease leads to high morbidity and mortality in patients with kidney failure. Autosomal Dominant Polycystic Kidney Disease (ADPKD) is a systemic disease with various cardiac abnormalities. Details on the cardiovascular profile of patients with ADPKD who are undergoing kidney transplantation (KT) and its progression are limited.

Methods

Echocardiographic data within 2 years before KT (1993-2020), and major adverse cardiovascular events (MACEs) after transplantation were retrieved. The primary outcome is to assess cardiovascular abnormalities on echocardiography at the time of transplantation in ADPKD as compared with patients without ADPKD matched by sex (male, 59.4%) and age at transplantation (57.2 ± 8.8 years).

Results

Compared with diabetic nephropathy (DN, n = 271) and nondiabetic, patients without ADPKD (NDNA) (n = 271) at the time of KT, patients with ADPKD (n = 271) had lower rates of left ventricular hypertrophy (LVH) (39.4% vs. 66.4% vs. 48.6%), mitral (2.7% vs. 6.3% vs. 7.45) and tricuspid regurgitations (1.8% vs. 6.6% vs. 7.2%). Patients with ADPKD had less diastolic (25.3%) and systolic (5.6%) dysfunction at time of transplantation. Patients with ADPKD had the most favorable post-transplantation survival (median 18.7 years vs. 12.0 for diabetic nephropathy [DN] and 13.8 years for nondiabetic non-ADPKD [NDNA]; P < 0.01) and the most favorable MACE-free survival rate (hazard ratio = 0.51, P < 0.001). Patients with ADPKD had worsening of their valvular function and an increase in the sinus of Valsalva diameter post-transplantation (38.2 vs. 39.9 mm, P < 0.01).

Conclusion

ADPKD transplant recipients have the most favorable cardiac profile pretransplantation with better patient survival and MACE-free survival rates but worsening valvular function and increasing sinus of Valsalva diameter, as compared with patients with other kidney diseases.

Stress Reduction in the Prevention of Left Ventricular Hypertrophy: A Randomized Controlled Trial of Transcendental Meditation and Health Education in Hypertensive African Americans

Background

African Americans have disproportionately high rates of cardiovascular disease (CVD). Left ventricular hypertrophy (LVH) is an independent risk factor for CVD and may contribute to this disparity. Psychological stress contributes to LVH in African Americans and other populations.

Objective

This study evaluated the effects of stress reduction with the Transcendental Meditation (TM) technique on preventing LVH in African American adults with hypertension.

Setting

Martin Luther King Hospital - Charles R. Drew University of Medicine and Science, Los Angeles, CA.

Method

In this trial, 85 African American adults (average 52.8 years) were randomly assigned to either TM program or health education (HE) control group and completed posttesting. Participants were tested at baseline and after six months for left ventricular mass index (LVMI) by M-mode echocardiography, blood pressure, psychosocial stress and behavioral factors. Change in outcomes was analyzed between groups by ANCOVA and within groups by paired t-test.

Results

The TM group had significantly lower LVMI compared with the HE group (-7.55gm/m², 95% CI -14.78 to -.34 gm/m², P=.040). Both interventions showed significant within group reductions in BP, (SBP/DBP changes for TM: -5/ -3 mm Hg, and for HE: -7/-6 mm Hg, P=.028 to <.001) although between group changes were not significant. In addition, both groups showed significant reductions in anger (P=.002 to .001). There were no other changes in lifestyle factors.

Conclusions

These findings indicate that stress reduction with TM was effective in preventing LVMI progression and thus may prevent LVH and associated CVD in high-risk African American patients.

Renin angiotensin aldosterone inhibition in the treatment of cardiovascular disease

A collective century of discoveries establishes the importance of the renin angiotensin aldosterone system in maintaining blood pressure, fluid volume and electrolyte homeostasis via autocrine, paracrine and endocrine signaling. While research continues to yield new functions of angiotensin II and angiotensin-(1-7), the gap between basic research and clinical application of these new findings is widening. As data accumulates on the efficacy of angiotensin converting enzyme inhibitors and angiotensin II receptor blockers as drugs of fundamental importance in the treatment of cardiovascular and renal disorders, it is becoming apparent that the achieved clinical benefits is suboptimal and surprisingly no different than what can be achieved with other therapeutic interventions. We discuss this issue and summarize new pathways and mechanisms effecting the synthesis and actions of angiotensin II. The presence of renin-independent non-canonical pathways for angiotensin II production are largely unaffected by agents inhibiting renin angiotensin system activity. Hence, new efforts should be directed to develop drugs that can effectively block the synthesis and/or action of intracellular angiotensin II. Improved drug penetration into cardiac or renal sites of disease, inhibiting chymase the primary angiotensin II forming enzyme in the human heart, and/or inhibiting angiotensinogen synthesis would all be more effective strategies to inhibit the system. Additionally, given the role of angiotensin II in the maintenance of renal homeostatic mechanisms, any new inhibitor should possess greater selectivity of targeting pathogenic angiotensin II signaling processes and thereby limit inappropriate inhibition.

Brain natriuretic peptide as a potential novel marker of salt-sensitivity in chronic kidney disease patients without cardiac dysfunction

Although the renin-angiotensin system (RAS) is counter-balanced by a salt-sensitive mechanism in the hypertensive state, both are reported to be up-regulated in chronic kidney disease (CKD) patients. We conducted this study to evaluate the associations among the RAS, renal function, hypertension, and atherosclerosis, as well as to identify markers for salt-sensitivity. A total of 213 pre-dialysis CKD patients with preserved cardiac function (EF >50 %) were enrolled. Their renal and cardiac biochemical markers and plasma renin activity (PRA) were measured, and echocardiography and carotid artery ultrasound were performed. Their salt intake was estimated by the NaCl excretion from a 24-h collected urine sample. The PRA was higher in patients with hypertension (p = 0.018), and had a significant negative correlation with the eGFR (r = -0.23, p = 0.0067). Importantly, the PRA had a strong negative correlation with the brain natriuretic peptide (BNP) level (r = -0.28, p = 0.017) regardless of whether the patients were being treated with RAS inhibitors. The BNP level was related to the renal functions (eGFR: p = 0.001, ACR: p = 0.009). There was a significant positive correlation between the BNP level and carotid intima-media thickness (p < 0.001). A multivariate analysis revealed that older age and an excess of NaCl excretion were independent predictors of BNP elevation (p = 0.02 and 0.003, respectively). Our analysis revealed details of the counterbalance between BNP and PRA, as well as identifying that excess salt intake is a predictor of BNP elevation. These results indicate that the BNP could be a possible valuable marker for salt sensitivity, and that high salt sensitivity could facilitate atherosclerosis in CKD patients.

Right ventricular remodeling and updated left ventricular geometry classification: is there any relationship?

OBJECTIVE

We sought to evaluate right ventricular (RV) structure and function in hypertensive patients with various left ventricular (LV) geometric patterns using an updated classification for LV geometry.

METHODS

This cross-sectional study included 232 hypertensive subjects. All the subjects underwent complete two-dimensional (2D) and three-dimensional (3D) echocardiographic examination. Using LV mass index, LV end-diastolic diameter and relative wall thickness, according to the updated classification, all subjects were divided into six different groups: normal LV geometry, concentric remodeling, eccentric LV hypertrophy (LVH), concentric, dilated, and concentric-dilated LVH.

RESULTS

RV wall thickness was increased in concentric and concentric-dilated LVH compared with normal LV geometry and LV concentric remodeling. RV longitudinal function was reduced in concentric and concentric-dilated patients compared with other hypertensive groups. 3D RV volumes were significantly higher in eccentric, dilated, and concentric-dilated LVH hypertensive subjects. Conversely, 3D RV ejection fraction was lower in these groups.

CONCLUSION

RV longitudinal myocardial function and 3D RV function are significantly influenced by LV geometry in hypertensive patients. RV remodeling is the most pronounced in the patients with concentric, dilated, and concentric-dilated LVH geometric patterns.

Clinical correlates and prognostic significance of change in standardized left ventricular mass in a community-based cohort of African Americans

Background

Though left ventricular mass (LVM) predicts cardiovascular events (CVD) and mortality in African Americans, limited data exists on factors contributing to change in LVM and its prognostic significance. We hypothesized that baseline blood pressure (BP) and body mass index (BMI) and change in these variables over time are associated with longitudinal increases in LVM and that such increase is associated with greater incidence of CVD.

Methods and Results

We investigated the clinical correlates of change in standardized logarithmically transformed‐LVM indexed to height2.7 (log‐LVMI) and its association with incident CVD in 606 African Americans (mean age 58±6 years, 66% women) who attended serial examinations 8 years apart. Log‐LVMI and clinical covariates were standardized within sex to obtain z scores for both visits. Standardized log‐LVMI was modeled using linear regression (correlates of change in standardized log‐LVMI) and Cox proportional hazards regression (incidence of CVD [defined as coronary heart disease, stroke, heart failure and intermittent claudication]). Baseline clinical correlates (standardized log‐LVM, BMI, systolic BP) and change in systolic BP over time were significantly associated with 8‐year change in standardized log‐LVMI. In prospective analysis, change in standardized LVM was significantly (P=0.0011) associated with incident CVD (hazards ratio per unit standard deviation change log‐LVMI 1.51, 95% CI 1.18 to 1.93).

Conclusions

In our community‐based sample of African Americans, baseline BMI and BP, and change in BP on follow‐up were key determinants of increase in standardized log‐LVMI, which in turn carried an adverse prognosis, underscoring the need for greater control of BP and weight in this group.

Plasma aldosterone and its relationship with left ventricular mass in hypertensive patients with early-stage chronic kidney disease

Plasma aldosterone concentrations (PACs) are often increased in the advanced stages of chronic kidney disease (CKD); however, PAC has not been fully investigated in early CKD. Moreover, little is known about the relationship between aldosteronemia and left ventricular (LV) mass in subjects with mild-to-moderate CKD. The study objectives were to analyze PAC, LV mass (LVM), LV geometry and their relationships, in a group of hypertensive patients with stage I-III CKD. One hundred ninety-five hypertensive patients with stage I-III CKD were enrolled and compared with a control group of 82 hypertensive patients without renal dysfunction. LVM was higher in subjects with CKD than in the control group and increased progressively with advancing stages of CKD (P=0.004). A similar trend was observed for PAC (P<0.0001), in which PAC was greater in CKD subjects with LV concentric geometry than in those with eccentric LV hypertrophy (P=0.01). Furthermore, in CKD patients, PAC was directly and significantly correlated with LVM (r=0.29; P<0.0001) and with relative wall thickness (RWT; r=0.36; P<0.0001). These associations remained significant even after adjustment for various confounding factors in multiple regression analyses (P<0.001). In summary, the results demonstrated that in CKD hypertensive patients, LVM, RWT and PAC are increased and related to each other from the earliest stages of renal dysfunction. Furthermore, it seems biologically plausible to speculate that aldosterone may promote a concentric geometry of the left ventricle and increase LVM in hypertensive patients with early CKD.

Aliskiren - an alternative to angiotensin-converting enzyme inhibitors or angiotensin receptor blockers in the therapy of arterial hypertension

There has been enormous progress in antihypertensive therapy over the last few decades. However, the management of arterial hypertension is still insufficient and more efforts are needed to improve both non-pharmacological and pharmacological treatment of this widely prevalent disease. Renin-angiotensin-aldosterone system (RAAS) inhibition is crucial both for blood pressure (BP) control and for prevention of organ damage or its development in patients with hypertension. Angiotensin-converting enzyme inhibitors and/or sartans block RAAS incompletely. Aliskiren is one of the novel drugs that has been introduced to antihypertensive therapy recently. Up to now no trial has confirmed that aliskiren is efficacious in reducing cardiovascular events. Double RAAS blockade with aliskiren was not always safe. This review article presents the current view on the place of aliskiren in the therapy of arterial hypertension.

Association of endostatin with mortality in patients with chronic heart failure

BACKGROUND

Experimental data imply that in decompensated heart failure (HF), the anti-angiogenic factor endostatin is increased. This study aimed to investigate whether the angiogenesis inhibitor endostatin is related to the risk of all-cause mortality in a prospective cohort study of chronic HF patients.

METHODS

In this prospective observational cohort study, endostatin serum concentrations were determined in patients with chronic HF. Mortality data were recorded during a median follow-up of 31 months.

RESULTS

One fifty one patients were included. The overall mortality rate was 20%. Baseline endostatin concentrations > 245 ng/mL were associated with higher risk of all-cause mortality [HR 8·7 (95% CI 2·5-30·0); P = 0·001] in the multivariate analysis as compared to endostatin concentrations ≤ 245 ng/mL. When both endostatin and NT-proBNP were above the calculated cut-off of 245 ng/mL and 2386 pg/mL, respectively, the prognostic utility of both biomarkers increased [HR 40·8 (95% CI 4·7-354·6); P = 0·001] compared with values lower than the cut-offs.

CONCLUSIONS

Serum endostatin concentrations are independently associated with all-cause mortality. Furthermore, combination of endostatin and NT-proBNP discriminates patients at high risk.

Relationship between Plasma Aldosterone Levels and Left Ventricular Mass in Hypertensive Africans

Background. Hypertension is the most common cardiovascular disease worldwide and is a major cause of morbidity and mortality. Studies have suggested that the activity of the renin-angiotensin-aldosterone system play a major role in the target organ damage such as left ventricular hypertrophy occuring in hypertension. We sought to determine the relationship between plasma aldosterone and left ventricular mass in untreated African hypertensives. Methods. We recruited 82 newly diagnosed and untreated hypertensives and 51 normal controls. Measurements obtained included echocardiographic LV mass index, plasma aldosterone and renin. Results. The hypertensive subjects had lower renin levels (21.03[6.974] versus 26.66[7.592] ng.mL⁻¹, P = 0.0013), higher LV mass index (52.56[14.483] versus 42.02[8.315] g.m^−2.7P < 0.0001) when compared with the controls. There were no univariate associations between LV mass index and plasma aldosterone (r = 0.0179, P = 0.57) and between LV mass index and plasma renin (r = 0.0887, P = 0.61). In a multivariate model involving LV mass index and age, sex, body mass index (BMI), plasma aldosterone, plasma renin and systolic blood pressure (SBP), only age (P = 0.008), BMI (P = 0.046), and SBP (P = 0.001) were independently associated with the LV mass index. Conclusions. In this group of hypertensive Africans, there is no independent association of plasma aldosterone with LV mass. The height of the blood pressure, the body mass index and the age of the subjects determined the LV mass.

Elevated circulating levels of copper and nickel are found in elderly subjects with left ventricular hypertrophy

Identified risk factors for left ventricular hypertrophy (LVH) are hypertension, diabetes and obesity. However, since these risk factors only explain a part of the variation in left ventricular mass, we investigated if trace and heavy metals might also play a role in LVH. In the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study, left ventricular mass index (LVMI) and relative wall thickness (RWT) were determined by echocardiography together with eleven different trace and heavy metals in 993 subjects aged 70 years. Only copper levels were significantly related to LVMI following adjustment for sex, blood pressure, antihypertensive treatment, diabetes and body mass index (BMI) (p<0.0001). However, both copper (Cu) and nickel (Ni) were related to RWT following adjustment (p<0.0001). When divided into four geometric groups, both Cu and Ni were elevated in subjects with concentric remodelling and concentric LVH, but not in those with eccentric hypertrophy, when compared to subjects with a normal left ventricle. No relationships were found for zinc, aluminium, manganese, molybdenum, mercury, lead, cadmium, cobalt or chromium. Elevated levels of copper and nickel are found in elderly subjects with LVH, especially of the concentric type, following adjustment for known risk factors for LVH.

Aliskiren as a novel therapeutic agent for hypertension and cardio-renal diseases

Objectives

High blood pressure (BP) is a major risk factor for cardiovascular and renal complications. A majority of treated hypertensive patients still complain of high BP. The renin-angiotensin aldosterone system (RAAS) has been a centre-stage target for all the cardiovascular and cardio-renal complications. Aliskiren, is the first direct renin inhibitor (DRI) to be approved by the US FDA. Renin controls the rate-limiting step in the RAAS cascade and hence is the most favorable target for RAAS suppression.

Key findings

This review article strives to summarize the pharmacokinetic, preclinical and clinical studies done so far pertaining to the efficacy of aliskiren. Further, the pharmacology of aliskiren has been comprehensively dealt with to enhance understanding so as to further research in this unfathomed area in the multitude of cardiovascular disorders and renal diseases.

Summary

Aliskiren has been shown to have comparable BP-lowering effects to other RAAS inhibitors. Recent clinical trials have indicated that it might contribute significantly in combination with other agents for the protection of end-organ diseases.

The relationship between metabolic syndrome and left ventricular mass index in obese children

OBJECTIVE

To investigate the relationships between metabolic syndrome (MS), other metabolic features and left ventricular mass index (LVMI) in a population of obese children and adolescents with MS.

METHODS

Two hundred and eight obese children and adolescents (119 females and 89 males, mean age: 11.9±2.7 years) and control subjects (24 females and 26 males, mean age: 11.4±2.9 years) were enrolled in the study. The insulin sensitivity index and LVMI were determined. The International Diabetes Federation criteria were used to diagnose MS.

RESULTS

The obese patients were divided into MS group (n=55) and non-MS (n=153) group. The values of LVMI in the MS group were significantly higher than those in the non-MS group (p=0.014). The present LVMI cut-off point of 33 g/m² for the diagnosis of MS yielded a sensitivity of 97% and a specificity of 98%. LVMI was found to be positively correlated in univariate analysis with height, weight, body mass index (BMI) SDS, fasting insulin level, homeostasis model assessment of insulin resistance (HOMA-IR) and fasting glucose to insulin ratio (FGIR) and negatively correlated with quantitative insulin sensitivity check index (QUICK-I).

CONCLUSIONS

We suggest that our optimal LVMI cut-off value for identifying MS may be considered as a sensitive index in screening obese children and adolescents for pediatric MS. Assessment of LVMI in obese children and adolescents may be used as a tool in predicting the presence of MS and its associated cardiovascular risks.

Renoprotection, renin inhibition, and blood pressure control: the impact of aliskiren on integrated blood pressure control

Hypertension (HTN) is an important factor in progressive loss of renal function. The kidney can be both a contributor to and a target of HTN. The functional integrity of the kidney is vital for the maintenance of cardiovascular homeostasis. Chronic activation of the renin system causes HTN and, ultimately, end-organ damage. Direct renin inhibitors (DRIs) inhibit plasma renin activity (PRA), thereby preventing the conversion of angiotensinogen to angiotensin I; consequently, the levels of both Ang I and Ang II are reduced. There is no compensatory increase in PRA activity with DRIs as seen with angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs). There are reasons to speculate that renin inhibition might prove to be a superior strategy for blocking the renin-angiotensin-aldosterone system compared with ACEIs or ARBs. Evidence for the efficacy of aliskiren (a DRI) is considered to be relatively strong, based on published, short-term, double-blind, randomized, controlled trials showing that aliskiren is as effective as other antihypertensive agents in reducing blood pressure (BP), with no rebound effects on BP after treatment withdrawal. When combined with diuretics, fully additive BP reduction is seen. When given with an ACEI or ARB, aliskiren produces significant additional BP reduction indicative of complimentary pharmacology and more complete renin-angiotensin system blockade.

The association between left ventricular hypertrophy and biomarkers in patients on continuous ambulatory peritoneal dialysis

Background and Objectives

Left ventricular hypertrophy (LVH) is a major cardiovascular complication and an important predictor of mortality in patients with end stage renal disease. Some studies have shown that the serum aldosterone levels are correlated with LVH in non-diabetic patients undergoing hemodialysis. The objective of this study was to elucidate the relationships between serum biomarkers, including aldosterone, and echocardiographic findings, such as LVH, in patients on peritoneal dialysis.

Subjects and Methods

Thirty patients on continuous ambulatory peritoneal dialysis (CAPD) for >12 months at Soonchunhyang University Cheonan Hospital were included. Transthoracic echocardiography was performed and the left ventricular mass index (LVMI) was calculated using the Devereux formula. Serum biomarkers {N-terminal pro B-type natriuretic peptide (NT-proBNP), troponin T, C-reactive protein, renin, and aldosterone} were measured.

Results

Sixteen of 30 patients had LVH on the basis of the LVMI. The mean serum aldosterone level was 62.53±60.73 pg/mL (range, 5.03-250.68 pg/mL). LVH, on the basis of the LVMI, was not correlated with the serum aldosterone level. The serum aldosterone levels were not associated with echocardiographic findings, even with co-existing diabetes mellitus. The LVMI had a negative correlation with the hemoglobin (r=-0.405, p=0.029) and hematocrit (r=-0.374, p=0.042), and a positive correlation with NT-proBNP (r=0.560, p=0.002). The other biomarkers (renin, aldosterone, troponin T, and C-reactive protein) were not correlated with the LVMI. The LVMI was correlated with the left atrium volume index (r=0.675, p<0.001).

Conclusion

NT-proBNP is a good marker to predict LVH in patients undergoing CAPD. The serum aldosterone level is not correlated with LVMI, even with co-existing diabetes mellitus.

Plasma aldosterone and its relationships with left ventricular mass in essential hypertensive patients with the metabolic syndrome

BACKGROUND

The association of aldosterone with the metabolic syndrome (MetS) has not been fully elucidated. The aim of our study was to evaluate the relationships of plasma aldosterone concentration (PAC) with MetS and left ventricular mass (LVM) in nondiabetic Caucasian patients with essential hypertension.

METHODS

Measurements were taken with the patients off antihypertensive medications. The measurements included 24-h blood pressure (BP) readings, plasma renin activity (PRA) and aldosterone, and an echocardiogram.

RESULTS

Subjects with MetS (n = 201) had higher age-adjusted PAC (10.2 +/- 5.8 vs. 11.6 +/- 5.9 ng/dl; P = 0.01) and greater age-adjusted LVM indexed for height2.7 (LVMH2.7) (56 +/- 19 vs. 62 +/- 20 g/m2; P = 0.001) than those without MetS (n = 249). The difference in respect of PAC between the two groups was independent of PRA and was attributable mainly to obesity. After adjusting for potential confounders, LVMH2.7 was associated with MetS as a whole (beta = 0.11; P = 0.02) and with body mass index (BMI) (beta = 0.19; P < 0.0001) in the overall population. The latter relationship was attenuated (beta = 0.15; P = 0.001) after further adjustment for PAC. In the MetS group the association of LVMH2.7 with PAC held (beta = 0.19; P = 0.007) in multivariate analyses. In subjects without MetS, this relationship had only borderline statistical significance.

CONCLUSIONS

Our results suggest that the elevated PAC related to obesity may help to explain the increased LVM observed in association with MetS, and may contribute to enhancing the cardiovascular risk associated with MetS.

Left ventricular hypertrophy and clinical outcomes in hypertensive patients

The prevalence of left ventricular hypertrophy (LVH) rises with severity of hypertension (HT), age, and obesity. Its prevalence ranges from 20% in mildly hypertensive patients to almost 100% in those with severe or complicated HT. However, the diagnosis of LVH is not straightforward, and the definitions and criteria used in clinical studies lack consistency. While many factors play a role in the onset and progression of LVH, blood pressure (BP) is recognized as a central factor. Twenty-four-hour BP measurements are more closely related to LVH than conventional BP readings taken in the clinician's office. Increased renin-angiotensin system (RAS) activity also plays an important role in the development of LVH, and various studies show a correlation between plasma renin activity and left ventricular mass (LVM). LVH is a recognized marker of HT-related target organ damage, and a strong and independent risk factor for adverse cardiovascular (CV) outcomes. CV risk increases with increasing LVM, and decreases with regression of LVH in response to antihypertensive treatment. Therefore the detection, prevention, and reversal of LVH are important goals in HT management. Most antihypertensive drugs can attenuate BP and LVH. However, each drug class may induce LVH regression to a different extent and these extents seldom correlate with the degree of BP reduction achieved. Data from the few large comparative studies in this area suggest that certain classes of antihypertensive drugs and/or their combinations are more effective than others. In particular, calcium channel blockers and drugs that target the RAS, such as angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs), appear to have a specific effect on LVH, independent of BP reduction. Guidelines, therefore, have recommended these drug classes for the treatment of hypertensive patients with LVH.

Impact of metabolic syndrome on left ventricular mass in overweight and obese hypertensive subjects

BACKGROUND

Metabolic syndrome (MS) has been associated with an increased left ventricular (LV) mass in recent reports. Little is known about the association of MS with LV mass (LVM) in overweight and obese individuals. The aim of our study was to investigate the relation between MS and LVM in a population of overweight and obese hypertensive subjects.

METHODS

289 non-diabetic essential hypertensives with a body mass index >25 kg/m2, were enrolled. In all subjects routine blood chemistry, echocardiographic examination and 24-h ambulatory blood pressure monitoring were performed.

RESULTS

In the group of overweight patients, participants with MS (n=58), when compared to those without it (n=127), exhibited significantly greater LVM indexed for height(2.7) (LVMH(2.7)) (50+/-12 vs 44+/-11 g/m(2.7); p=0.0001), even after controlling for age, gender and 24-h systolic blood pressure. Similar results were obtained in the group of obese individuals, being LVMH(2.7) (56+/-12 vs 44+/-9 g/m(2.7); p<0.0001) greater in subjects with MS (n=77) than in those without MS (n=27), even after adjustment for age, gender and clinic systolic blood pressure. The independent association of MS with LVMH(2.7) in overall study population was confirmed by linear multiple regression analyses (beta=0.20; p=0.0004).

CONCLUSIONS

MS seems to increase LVM over and above the potential contribution of blood pressure, body size and other single components of this syndrome. Since LV hypertrophy is a well-known predictor of cardiovascular events, our results may partly explain the enhanced cardiovascular risk associated with MS.

Aliskiren

Aliskiren (Tekturna) is an orally active, nonpeptidic inhibitor of renin, the enzyme involved in the initial and rate-limiting step of the renin-angiotensin system (RAS). In the US, aliskiren is approved for the treatment of hypertension and may be used alone or in combination with other antihypertensive agents. Monotherapy with aliskiren 150-300mg once daily was effective in lowering blood pressure (BP) and providing 24-hour BP control; it was generally well tolerated when administered for up to 1 year to patients with mild to moderate hypertension. In the short term (1-3 months), the BP-lowering effect of aliskiren 150-300mg once daily was significantly greater than that of hydrochlorothiazide (HCTZ) 12.5-25mg once daily and noninferior to, or significantly greater than, that of ramipril 5-10mg once daily. It was similar to that of valsartan 160-320mg once daily and losartan 100mg once daily, and similar to, or significantly greater than, that of irbesartan 150mg once daily. Aliskiren provided significant additional BP-lowering effects when combined with HCTZ 12.5-25 mg/day, ramipril 5-10 mg/day, amlodipine 5mg once daily or valsartan 160-320 mg/day; combination therapy was well tolerated. Long-term administration of aliskiren-based therapy was superior to HCTZ- and ramipril-based therapies in lowering BP after 6 months, and was similarly well tolerated. The ultimate role of aliskiren will be determined by the results of target organ protection studies, which are ongoing, and a cardiovascular outcome trial, which is planned. Nonetheless, by offering a new approach to the blockade of the RAS, aliskiren provides a useful addition to the therapeutic options available to treat patients with mild to moderate hypertension.

The metabolic syndrome and its relationship to hypertensive target organ damage

High blood pressure is often associated with various metabolic abnormalities, including abdominal obesity, dyslipidemia, elevated plasma glucose, and insulin resistance, which are the main features of the metabolic syndrome. The metabolic syndrome is extremely common worldwide. This high prevalence is of considerable concern because several studies suggest that the metabolic syndrome carries an increased risk for cardiovascular events. Several lines of evidence seem to indicate that the metabolic syndrome is associated with an increased prevalence of preclinical cardiovascular and renal changes, such as left ventricular hypertrophy, microalbuminuria, impaired aortic elasticity, and early carotid atherosclerosis, most of which are recognized as significant independent predictors of adverse cardiovascular outcomes. It is conceivable that these data may partly explain the high rates of cardiovascular morbidity and mortality that are observed in patients with the metabolic syndrome.

Left ventricular hypertrophy and arterial wall thickening in children with essential hypertension

OBJECTIVE

Our aim was to determine the prevalence of left ventricular hypertrophy (LVH) and increased intima-media thickness (IMT) in Caucasian children with newly diagnosed, untreated essential hypertension (EH).

PARTICIPANTS

Our study cohort consisted of 72 children with EH (mean age: 14.5 years; range: 5-18 years). The control groups consisted of 103 age-matched, healthy children.

METHODS

We evaluated the left ventricular mass (LVM), intima-media thickness in the carotid (cIMT) and superficial femoral (fIMT) arteries, 24-h ambulatory blood pressure, and biochemical cardiovascular risk factors.

RESULTS

Of the hypertensive children examined, 41.6% had LVM above the 95th percentile, and 13.2% had LVM above 51 g/m2.7. Of the hypertensive subjects, the cIMT was above 2 SDS of normal values in 38.8%, and the flMT was above 2 SDS of normal values in 17.5%. Patients with LVM above 51 g/m2.7 had a higher birth weight than other patients. LVM, cIMT, and fIMT correlated with 24-h SBP and pulse pressure; LVM also correlated with homocysteine and serum uric acid concentrations. fIMT correlated with low Aprotein A1 (ApoA1), higher ApoB and C reactive protein, and daily sodium excretion. Step-wise regression analysis revealed that serum uric acid and higher birth weight were predictors for LVM, pulse pressure was a predictor for cIMT, and ApoB was a predictor for fIMT.

CONCLUSIONS

A significant number of adolescents with EH already had cardiovascular damage at diagnosis. LVM and markers of arterial injury correlate with SBP, biochemical, and perinatal cardiovascular risk factors. Serum uric acid and higher birth weight are predictors of LVM.

Role of leptin in blood pressure regulation and arterial hypertension

Leptin is a 16-kDa protein secreted by white adipose tissue that is primarily involved in the regulation of food intake and energy expenditure. Plasma leptin concentration is proportional to the amount of adipose tissue and is markedly increased in obese individuals. Recent studies suggest that leptin is involved in cardiovascular complications of obesity, including arterial hypertension. Acutely administered leptin has no effect on blood pressure, probably because it concomitantly stimulates the sympathetic nervous system and counteracting depressor mechanisms such as natriuresis and nitric oxide (NO)-dependent vasorelaxation. By contrast, chronic hyperleptinemia increases blood pressure because these acute depressor effects are impaired and/or additional sympathetic nervous system-independent pressor effects appear, such as oxidative stress, NO deficiency, enhanced renal Na reabsorption and overproduction of endothelin. Although the cause-effect relationship between leptin and high blood pressure in humans has not been demonstrated directly, many clinical studies have shown elevated plasma leptin in patients with essential hypertension and a significant positive correlation between leptin and blood pressure independent of body adiposity both in normotensive and in hypertensive individuals. In addition, leptin may contribute to end-organ damage in hypertensive individuals such as left ventricular hypertrophy, retinopathy and nephropathy, independent of regulating blood pressure. Here, current knowledge about the role of leptin in the regulation of blood pressure and in the pathogenesis of arterial hypertension is presented.

The effect of percutaneous dilatation of renal arterial stenosis on captopril renography in hypertension

BACKGROUND

The clinical effects of percutaneous transluminal renal artery angioplasty (PTRA) in patients with renal vascular stenosis and hypertension is controversial.

METHODS

We consecutively recruited all 23 patients referred for evaluation of renovascular hypertension that eventually underwent unilateral PTRA, to be investigated with captopril MAG3 renography (CR), both before and after the endovascular procedure. Data were evaluated on an intention-to-treat basis.

RESULTS

We found that the relative MAG3 clearance of the stenotic kidney increased (from 29.9+/-14% to 35.1+/-14%, p=0.01) and that the creatinine levels fell following the intervention (from 110+/-19 to 99+/-17 micromol/l, p=0.0003). Blood pressure levels were also lowered (from 173+/-32/93+/-17 to 158+/-31/86+/-15 mmHg, p<0.006) while the mean number of anti-hypertensive drugs was unchanged following PTRA (2.9+/-1.4 before and 2.8+/-1.3 drugs after the intervention, respectively, p=0.6).

CONCLUSION

This prospective trial showed statistically significant improvements of individual kidney function as measured by CR and blood pressure in subjects with suspected renovascular hypertension treated with PTRA. Although the endovascular procedure was found to be safe, the magnitude of the absolute improvements was rather modest.

Insulin resistance and plasma triglyceride level are differently related to cardiac hypertrophy and arterial stiffening in hypertensive subjects

OBJECTIVE

The frequent association between the type 2 diabetes mellitus and cardio-vascular diseases suggests that metabolic factors may contribute to cardio-vascular remodeling. The aim of our study was to examine the relationships between left ventricular posterior wall thickness (LVPWT), pulse wave velocity (PWV), and the metabolic abnormalities of insulin resistance syndrome, in hypertensive patients.

METHODS

In 227 consecutive hypertensives, we examined the relationships between LVPWT, PWV, and metabolic factors: plasma glucose, insulin, total cholesterol, high density lipoprotein (HDL)-cholesterol, triglycerides levels as well as the homeostasis model assessment of insulin resistance (HOMA). The Pearson correlation coefficient and multiple regression analysis (including age, gender, body mass index, and 24-hour systolic blood pressure) were used as statistical tests.

RESULTS

In univariate analysis, glucose, HDL-cholesterol, and triglycerides levels were related to LVPWT (r = 0.19, p < 0.05; r = -0.26, p < 0.001; r = 0.31, p < 0.001, respectively); all metabolic variables, except HDL-cholesterol, correlated to PWV (plasma glucose r = 0.25, p < 0.001; total cholesterol r = 0.22, p < 0.01; triglycerides r = 0.20, p < 0.01; insulin r = 0.19, p < 0.01; HOMA r = 0.27; p < 0.001). In the multivariate model, plasma triglycerides remained correlated with LVPWT (beta = 0.19, p < 0.02) independently of systolic blood pressure, plasma aldosterone, and normetanephrine. Only HOMA and insulin level remained associated with PWV (beta = 0.14; beta = 0.13 respectively, p < 0.05).

CONCLUSIONS

These data suggest that among typical metabolic abnormalities of insulin resistance syndrome, plasma triglycerides, and insulin as well as degree of insulin resistance may contribute to cardiac hypertrophy and arterial stiffening independently of hemodynamic and hormonal factors.

Direct Renin Inhibition with Aliskiren in Hypertension and Target Organ Damage

The Joint National Committee and the World Health Organization are in agreement that hypertension in most patients who are treated is controlled inadequately and that rates of cardiovascular morbidity remain high. Additional pharmacologic treatments could ameliorate this situation. The renin-angiotensin-aldosterone system has been a highly successful pharmacologic target, as the system is strongly implicated in the development of hypertension-related target organ damage. However, compensatory increases in plasma renin levels that lead to adjustments in angiotensin production and conversion present limitations for existing renin-angiotensin-aldosterone system inhibitors. A once-daily, orally effective, small-molecule renin inhibitor, aliskiren, is now available to address angiotensin production directly at its rate-limiting step. Studies in humans attest to an effective BP-lowering effect, a side effect profile no different from AT1 receptor blockers, and the option of combination therapies. A novel animal model of high human renin hypertension in the rat attest to target organ protection. Because angiotensin receptor blockade, angiotensin-converting enzyme inhibition, calcium channel blockade, and diuretic therapy all lead to sharp increases in plasma renin activity, aliskiren offers a novel circumvention.

Circulating leptin correlates with left ventricular mass in morbid (grade III) obesity before and after weight loss induced by bariatric surgery: a potential role for leptin in mediating human left ventricular hypertrophy

CONTEXT

Obesity is frequently associated with left ventricular hypertrophy, even when uncomplicated by hypertension or diabetes mellitus. Left ventricular hypertrophy is an important risk factor for congestive heart failure.

OBJECTIVE

The objective of this study was to evaluate the relationship between leptin and left ventricular mass in uncomplicated, morbid (grade 3) obesity and the existence of leptin receptors and intracellular signaling proteins in the human heart.

DESIGN

Left ventricular mass (LVM) was calculated through electrocardiogram reading in normotensive grade III obese patients (World Health Organization classification) undergoing bariatric surgery [laparoscopic adjustable gastric banding (LAGB)] at baseline and 1 yr later. The control group was composed of healthy lean normotensive subjects. Leptin receptors were detected by PCR and immunocytochemistry in human heart biopsies.

SETTING

This study was performed at university hospitals.

PATIENTS

Thirty-one grade 3 obese patients and 30 healthy nonobese normotensive, age- and sex-matched control subjects were studied.

INTERVENTION

Obese subjects underwent LAGB to induce weight loss and were evaluated at baseline and after 1 yr.

RESULTS

LVM, plasma leptin, glucose, insulin levels, and homeostasis model assessment index were higher in obese than in lean controls (P < 0.01); at univariate regression analysis, LVM correlated with body mass index, leptin, and homeostasis model assessment index; at multiple regression analysis, LVM only correlated with leptin levels (P = 0.001). Obese subjects were reevaluated 1 yr after LAGB, when their body mass index changed from 46.2 +/- 1.24 to 36.6 +/- 1.05 kg/m(2) (P < 0.01); the decrease in LVM correlated only with the decrease in leptin levels (P < 0.01). We demonstrated that long and short isoforms of the leptin receptor and intracellular proteins mediating leptin signaling were expressed in human heart by RT-PCR, immunocytochemistry, or both methods.

CONCLUSIONS

These data suggest that leptin could contribute to the left ventricular hypertrophy in humans.

Influence of metabolic syndrome on hypertension-related target organ damage

OBJECTIVES

The aim of our study was to analyse, in a wide group of essential hypertensive patients without diabetes mellitus, the influence of metabolic syndrome (MS) (defined according to the criteria laid down in the Third Report of the National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults) on markers of preclinical cardiac, renal and retinal damage.

DESIGN

Cross-sectional study.

SETTING

Outpatient hypertension clinic.

SUBJECTS AND METHODS

A total of 353 young and middle-aged hypertensives, free from cardiovascular and renal diseases (and 37% of whom had MS), underwent echocardiographic examination, microalbuminuria determination and non-mydriatic retinography.

RESULTS

When compared with subjects without MS, hypertensive patients with MS exhibited more elevated left ventricular (LV) mass (either normalized by body surface area or by height elevated by a power of 2.7), higher myocardial relative wall thickness, albumin excretion rate (AER) and a greater prevalence of LV hypertrophy (57.7% vs. 25.1%; P < 0.00001), of microalbuminuria (36.2% vs. 19.3%; P = 0.002) and of hypertensive retinopathy (87.7% vs. 48.4%; P < 0.00001). These results held even after correction for age, 24-h blood pressures, duration of hypertension, previous antihypertensive therapy, and gender distribution. The independent relationships between LV mass and MS, and between AER and MS, were confirmed in multivariate regression models including MS together with its individual components.

CONCLUSIONS

MS may amplify hypertension-related cardiac and renal changes, over and above the potential contribution of each single component of this syndrome. As these markers of target organ damage are well-known predictors of cardiovascular events, our results may partly explain the enhanced cardiovascular risk associated with MS.

Nurse-recorded clinic and ambulatory blood pressures correlate equally well with left ventricular mass and carotid intima-media thickness

OBJECTIVE

To assess relationships between noninvasive ambulatory blood pressure (BP), clinic BP (mean value of three readings in the seated position measured by nurses), structural cardiac indices, intima-media thickness of the common carotid artery and several hormones.

DESIGN

Cross-sectional study of 75 subjects with hypertension and left ventricular hypertrophy (HTH) according to echocardiography, 35 subjects with hypertension and normal left ventricular dimensions (HT) and 23 normotensive subjects (NT).

RESULTS

We found an excellent correlation between mean 24-h ambulatory BP and clinic BP, the r-value for systolic BP being 0.82 and for diastolic levels 0.78 (both P < 0.0001). Clinic and ambulatory BP correlated equally well with left ventricular (LV) mass index (r-values between 0.55 and 0.64, all P < 0.0001) and to intima-media thickness of the carotid artery (r = 0.18-0.34, P < 0.01). The systolic white-coat effect (clinic BP - day-time BP) was higher in the HTH and HT compared with NT and was weakly correlated to LV mass index (r = 0.18, P = 0.04). Nondippers (mean arterial night/day BP ratio of > 0.9) had higher brain (6.1 +/- 7.5 pmol L(-1) vs. 3.7 +/- 3.2 pmol L(-1), P = 0.01) and atrial (14 +/- 3.4 pmol L(-1) vs. 9.3 +/- 5.4 pmol L(-1), P = 0.04) natriuretic peptide levels, and also exhibited a lower ejection fraction (49 +/- 8% vs. 57 +/- 9%, P = 0.006), than dippers.

CONCLUSION

Clinic BP recordings performed by nurses as three measurements 1 min apart provide excellent relationship to target organ damage. Nondippers exhibited signs of a more advanced hypertensive organ damage than dippers which corresponds well with the poor prognosis linked to this condition.

Influence of dietary sodium on the renin-angiotensin-aldosterone system and prevalence of left ventricular hypertrophy by EKG criteria

We investigated the interplay of dietary sodium and renin-angiotensin-aldosterone system (RAAS) activity with the prevalence of left ventricular hypertrophy (LVH) in essential hypertension. Electrocardiograms (EKG) were reviewed for the presence of LVH in 160 hypertensive patients. We then compared the rate of LVH to levels of plasma renin activity (PRA) and serum aldosterone under high and low sodium diet conditions. On high sodium diet, serum aldosterone was significantly higher (7.7+/-0.93 vs 5.7+/-0.35 ng/dl, P=0.02) in participants with LVH. With low sodium diet and upright posture, PRA was significantly lower in subjects with LVH vs those without (5.6+/-1.1 vs 7.6+/-0.56 ng/ml/h, P=0.026). Aldosterone levels on low sodium diet were not different between those with and those without LVH. PRA was then dichotomized at the lowest quartile under low sodium/upright posture conditions to define a 'low renin' group. In a multivariate logistic regression containing renin status (low renin vs normal/high renin), aldosterone on a high sodium diet, age, body mass index, gender, race, duration of hypertension, systolic and diastolic blood pressure and salt-sensitivity only low-renin status on a low sodium diet (P=0.019) and serum aldosterone on a high sodium diet (P=0.04) were significant predictors of LVH. Thus, reduced modulation of renin activity in response to sodium restriction and an increased aldosterone on a high sodium diet appear to identify characteristics of hypertensive patients predisposed to abnormal cardiac remodelling.

Nt-proANP in plasma, a marker of salt sensitivity, is reduced in type 2 diabetes patients

OBJECTIVE

We recently showed that plasma concentration of N-terminal atrial natriuretic peptide (Nt-proANP) is strongly directly related to salt sensitivity. The aims of the present study were to test (i) whether plasma concentration of N-terminal brain natriuretic peptide (Nt-proBNP) is related to salt sensitivity and (ii) whether Nt-proANP, as a marker of salt sensitivity, differs between type 2 diabetes patients and nondiabetic subjects without a history of coronary heart disease.

METHODS

Nt-proBNP was determined in 30 Swedish normal subjects with heredity for primary hypertension and salt sensitivity was defined as the difference between mean arterial blood pressure after 1 week on a high-salt diet (240 mmol day(-1)) and 1 week on a low-salt diet (10 mmol day(-1)). Nt-proANP was measured in 253 patients with type 2 diabetes and in 230 nondiabetic subjects aged 40-70 years, all without a history of coronary heart disease.

RESULTS

Amongst the 30 subjects, in whom salt sensitivity was directly measured, Nt-proBNP was not correlated with salt sensitivity (R=-0.18, P=0.35). Nt-proANP (median, interquartile range) was lower in patients with type 2 diabetes (505, 387-661 pmol L(-1)) than in nondiabetic subjects (536, 421-696 pmol L(-1)) (P=0.02). In a multiple regression analysis heart rate (P <0.00001), diastolic blood pressure (P=0.02) and diabetes status (P=0.02) were inversely related whereas age (P <0.00001), cystatin C (P=0.0006), hypertension treatment (P=0.002) and female sex (P=0.006) were directly related to ln(Nt-proANP).

CONCLUSION

In contrast to Nt-proANP, Nt-proBNP is not related to salt sensitivity. Salt sensitivity, as estimated by Nt-proANP, seems to be reduced in type 2 diabetes.

Mineralocorticoids act centrally to regulate blood-borne tumor necrosis factor-α in normal rats

Excessive mineralocorticoid receptor (MR) stimulation induces neurohumoral excitation and cardiac and vascular fibrosis. In heart failure (HF) rats, with excessive neurohumoral drive, central infusion of the MR antagonist spironolactone (SL) decreases blood-borne TNF-α. This study aimed to determine whether DOCA, a precursor of aldosterone, acts centrally to stimulate TNF-α production in normal rats. DOCA (5 mg sc daily for 8 days) induced a progressive increase in TNF-α beginning on day 3 and increased tissue TNF-α in hypothalamus, pituitary, and heart but not in other brain and peripheral tissues harvested on day 9. A continuous intracerebroventricular infusion of SL (100 ng/h) blocked the plasma TNF-α response. Oral SL (1 mg/kg) blocked the plasma and tissue TNF-α responses. Thus DOCA increases TNF-α in brain, heart, and blood in normal rats. Activation of brain MR appears to account for the increase in plasma TNF-α. These findings have important implications for the understanding of pathophysiological states (e.g., HF, hypertension) characterized by high circulating levels of aldosterone.

Long-Term Effects of Irbesartan and Atenolol on the Renin-Angiotensin-Aldosterone System in Human Primary Hypertension

We examined long-term influence of the angiotensin II type 1-receptor blocker irbesartan and the beta1-adrenergic receptor blocker atenolol on some neurohormonal systems implicated in the pathophysiology of cardiac hypertrophy. Thus, 115 hypertensive patients with left ventricular hypertrophy were randomized to receive double-blind irbesartan or atenolol, with additional therapy if needed. Neurohormone measurements and echocardiography were performed at weeks 0, 12, 24, and 48. Left ventricular mass was reduced more by irbesartan than by atenolol (-26 g/m2 versus -14 g/m2, P = 0.024), despite similar reductions in blood pressure. Plasma renin activity and angiotensin II increased (P < 0.001) by irbesartan (0.9 +/- 0.7 to 3.4 +/- 4.2 ng/mL x h, and 3.0 +/- 1.6 to 13.0 +/- 17.7 pmol/L), but decreased (P < 0.01) by atenolol (1.0 +/- 0.6 to 0.7 +/- 0.6 ng/mL x h, and 3.4 +/- 1.6 to 3.2 +/- 2.2 pmol/L). Serum aldosterone decreased (P < 0.05) by both irbesartan (346 +/- 140 to 325 +/- 87 pmol/L) and atenolol (315 +/- 115 to 283 +/- 77 pmol/L). Changes in left ventricular mass by irbesartan related inversely to changes in plasma renin activity, angiotensin II, and aldosterone (all P < 0.05). Plasma levels and 24-hour urinary excretions of catecholamines, plasma leptin, proinsulin, insulin and insulin sensitivity remained largely unchanged in both groups. Thus, the renin-angiotensin aldosterone system appears to be an important non-hemodynamic factor in the regulation of left ventricular mass.

Blood pressure and left ventricular geometric pattern determine diastolic function in hypertensive myocardial hypertrophy

Abnormal left ventricular (LV) diastolic relaxation is an early sign of hypertensive heart disease. Whether LV diastolic dysfunction is caused directly by raised blood pressure, or by structural changes related to LV hypertrophy remains controversial. We examined 115 hypertensive patients with LV hypertrophy, and two age- and gender-matched groups (38 hypertensive patients without LV hypertrophy and 38 normotensive subjects) by echocardiography to assess determinants of LV diastolic function, and the relation between diastolic function and LV geometric pattern. Diastolic function was evaluated by the E/A-ratio, E wave deceleration time (E-dec), isovolumic relaxation time (IVRT), and the atrioventricular plane displacement method (AV-LA/AV-mean). A multivariate analysis (including gender, age and body mass index) shows diastolic function to be inversely related to blood pressure, LV wall thickness and LV mass, but not to LV end diastolic diameter. The E/A-ratio generally showed the strongest relations. Only the E/A-ratio and AV-LA/AV-mean were related to heart rate. By stepwise regression analysis, age was the strongest determinant for the E/A-ratio, E-dec and AV-LA/AV-mean, followed by systolic blood pressure, heart rate and LV wall thickness. For IVRT, however, LV wall thickness appeared strongest, followed by systolic blood pressure and age. In conclusion, blood pressure and LV wall thickness both have independent influence on LV diastolic function. Age and blood pressure are the most important factors to determine the E/A-ratio and E-dec, whereas LV geometry and blood pressure are most important when IVRT is used. AV-LA/AV-mean may not be useful in hypertensive LV hypertrophy.

The association between leptin and left ventricular hypertrophy: a population-based cross-sectional study

BACKGROUND AND OBJECTIVES

Plasma leptin levels have been shown to be an independent risk factor for cardiovascular disease. Leptin has been shown to have sympathetic and vascular effects, and may increase cardiovascular risk through increased blood pressure, left ventricular hypertrophy, or atherosclerotic mechanisms. This study examines whether leptin levels, independent of body mass and insulin resistance, are a risk factor for hypertension and left ventricular hypertrophy.

METHODS AND PARTICIPANTS

A population-based, cross-sectional sample of 410 adults from rural Spain was studied. The correlations between plasma leptin levels and left ventricular mass index, sum of wall thicknesses, and blood pressure were calculated. Multiple linear regression analysis was used to adjust for other cardiovascular risk factors.

RESULTS

After adjusting for age, body mass index, systolic blood pressure, sex, and insulin resistance, leptin was inversely associated with left ventricular mass index (beta = -0.20, P < 0.01). Leptin was also inversely related to the sum of wall thicknesses; however, this association did not reach statistical significance (beta = -0.12, P = 0.063). Leptin was not statistically associated with blood pressure after adjusting for body mass index.

CONCLUSIONS

The results do not support the hypothesis that leptin increases cardiovascular risk by increasing left ventricular mass index or blood pressure. Other mechanisms, related to atherosclerosis, could explain the increased risk of cardiovascular diseases observed with high leptin levels.