Plasma renin activity, serum aldosterone concentration and selected organ damage indices in essential arterial hypertension

INTRODUCTION

The aim of this study was to assess the relations between plasma renin activity (PRA), serum aldosterone concentration (ALDO) and selected asymptomatic organ damage (AOD) indices in mild primary arterial hypertension (AH).

MATERIAL AND METHODS

We measured PRA, ALDO, and selected AOD indices (carotid-femoral pulse wave velocity (cfPWV), central aortic pulse pressure (cPP), estimated glomerular filtration rate (eGFR)) in 122 patients with untreated AH.

RESULTS

Patients with high PRA (≥ 0.65 ng/ml/h) were characterized by lower plasma sodium and aldosterone to renin ratio (ARR), higher ALDO, but a similar level of AOD indices compared to patients with low PRA. cfPWV (p = 0.04) and cPP (p = 0.019) increased with ARR, while eGFR decreased with ALDO (p = 0.008). Only eGFR was independently correlated with ALDO. In subjects with simultaneously high PRA and ARR values, we found significantly higher cfPWV (p = 0.02) and cPP (p = 0.04) and lower eGFR (p = 0.02) than in those with high PRA but low ARR values.

CONCLUSIONS

Assessment of the influence of the renin-angiotensin-aldosterone system (RAAS) on AOD should include the relationship between renin and aldosterone. The PRA itself has no predictive value for AOD. More advanced arterial stiffness and renal impairment are associated with increased PRA and ARR. The RAAS activity might be useful in AOD prediction and hypertension severity assessment.

Selected matrix metalloproteinases activity and hypertension-mediated organ damage in relation to uric acid serum level

BACKGROUND

Atherosclerosis is as a systemic inflammatory disease associated with the activation of many mediators, including matrix metalloproteinases (MMPs), and may be amplified by abnormal high serum uric acid (UA) concentration (hyperuricemia, HU). The aim of the study was to determine the relationship between serum UA concentration and activity of MMPs and their correlation with the hypertension-mediated organ damage (HMOD) intensity.

METHODS

109 patients untreated with antihypertensive, hypolipemic or urate-lowering drugs with diagnosed stage 1-2 essential hypertension were included in this study. In all participants blood pressure (BP) was measured, carotid-femoral pulse wave velocity (PWV), intima-media thickness (IMT), echocardiography and blood tests including UA, lipids and serum concentrations of MMPs (1, 2, 3, 9) were observed. The participants were divided into hyper- and normuricemic groups.

RESULTS

Uric acid concentration in the whole study group positively correlated with some HMOD parameters (IMT, PWV, left ventricular mass index, left atrial dimension). Among the studied metalloproteinases only MMP-3 activity positively correlated with serum UA concentration independently of age, body mass index and serum lipids (R2 = 0.11, p = 0.048). Multivariate regression analysis showed positive association between IMT and BP, UA concentration and MMP-3 activity, independently of waist circumference and serum lipids (R2 = 0.328, p < 0.002). Patients with HU were characterized by higher activity of MMP-3 than those without (19.41 [14.45; 21.74] vs. 13.98 [9.52; 18.97] ng/mL, p = 0.016).

CONCLUSIONS

The present results may support the thesis that UA and the increased by UA activity of MMPs may take part in the development of HMOD, especially IMT.

The relationship between plasma renin activity and serum lipid profiles in patients with primary arterial hypertension

Introduction:

The aim of the study was to evaluate clinical and biochemical differences between patients with low-renin and high-renin primary arterial hypertension (AH), mainly in reference to serum lipids, and to identify factors determining lipid concentrations.

Materials and methods:

In untreated patients with AH stage 1 we measured plasma renin activity (PRA) and subdivided the group into low-renin (PRA < 0.65 ng/mL/h) and high-renin (PRA ⩾ 0.65 ng/mL/h) AH. We compared office and 24-h ambulatory blood pressure, serum aldosterone, lipids and selected biochemical parameters between subgroups. Factors determining lipid concentration in both subgroups were assessed in regression analysis.

Results:

Patients with high-renin hypertension (N = 58) were characterized by higher heart rate (p = 0.04), lower serum sodium (p < 0.01) and aldosterone-to-renin ratio (p < 0.01), and significantly higher serum aldosterone (p = 0.03), albumin (p < 0.01), total protein (p < 0.01), total cholesterol (p = 0.01) and low-density lipoprotein cholesterol (LDL-C) (p = 0.04) than low-renin subjects (N = 39). In univariate linear regression, only PRA in the low-renin group was in a positive relationship with LDL-C (R² = 0.15, β = 1.53 and p = 0.013); this association remained significant after adjustment for age, sex, and serum albumin and aldosterone concentrations.

Conclusions:

Higher serum levels of total and LDL-C characterized high-renin subjects, but the association between LDL-C level and PRA existed only in low-renin primary AH.

The relation between blood pressure components and left atrial volume in the context of left ventricular mass index

Left atrial enlargement (LAE) is a risk factor for cardiovascular complications and death. In hypertensive patients, LAE is usually due to left ventricular (LV) hypertrophy and diastolic dysfunction. We aimed to identify factors associated with LAE in patients with increased and normal left ventricular mass index (LVMI) with reference to pulsatile and steady components of blood pressure (BP).The study was carried out as a cross-sectional observation. In a group of inhabitants of suburban area of Cracow, Poland, we measured office, ambulatory and central BP, carotid-femoral pulse wave velocity (PWV), as well as echocardiographic indices and gathered anthropometric data, information on habits and relevant medical history. Further, with division according to sex-stratified dichotomised LVMI, we performed correlation analysis to identify possibly significant relations between measures of left atrial volume and other studied parameters. We also fitted regression models in order to assess the respective value of steady and pulsatile BP components as factors related to measures of left atrial volume.The mean age of 205 patients (136 females-66%) was 53.6 ± 8.3 years. We found higher values of PWV, office, ambulatory and central BPs in the group of LVMI above median value. This group had also greater left atrial volume index (LAVI), which correlated with LVMI (r = 0.36, P < .001) and ratio of early diastolic mitral peak flow velocity to early diastolic mitral annulus mean velocity in tissue Doppler imaging (E/e') (r = 0.24, P = .04).In the group of LVMI below the median, LAVI correlated with pulsatile and steady BP components. LAVI was independently predicted by mean arterial pressure (MAP) obtained from both ambulatory (MAP24h, β= 0.15; P = .045) and office measurements (MAPoffice, β = 0.35; P = .004), but not by pulse pressure.LV mass and function are the main determinants of LAVI. However, in persons with lower LV mass, LAVI depends on the steady component of blood pressure, but not pulsatile one. Increased LAVI reflects early changes in response to systemic blood pressure elevation.

[The influence of antihypertensive treatment on arterial stiffness, shear stress and activity of chosen matrix metalloproteinases]

The aim of the study was to compare therapeutic effects of chosen antihypertensive drugs on arterial stiffness, shear stress in carotid arteries and metalloproteinases activity, moreover analysis of relationship of these variables in the course of treatment.

METHODS

95 patients with essential arterial hypertension stage 1 or 2 were randomized to 6 months monotherapy with: quinapril, amlodipine, hydrochlorothiazide, losartan or bisoprolol. Each therapeutic group consisted of 19 patients (N=19). Before and then after 1, 3 and 6 months of treatment carotid-femoral pulse wave velocity (PWV) by using a Complior device, ultrasound of carotid arteries were performed. Blood samples for the measurement of whole blood viscosity were taken during each visit. Shear stress (SS) was calculated using measured variables: blood viscosity and velocity of blood flow. Serum concentration of metalloproteinase 3 (MMP-3) and plasma concentration of tissue inhibitor of metalloproteinase I (TIMP-1) were measured at the initial visit and after 6 months of treatment.

RESULTS

ANOVA for repeated measurements revealed for all groups significant decrease of PWV (ΔPWV) and MMP-3 (ΔMMP-3) concentration and increase of shear stress in carotid artery and TIMP-1 (ΔTIMP-1) concentration (p<0.05). No between groups differences appeared in above effects (p>0.05). The multiple regression analysis for the change of PWV (ΔPWV) in the study group considering all investigated variables at R2 = 0,27 revealed its significant relation to PWV at first visit, ΔTIMP-1, ΔMMP-3 and Δ shear stress counted for the maximum flow velocity in common carotid artery. Conclusion: Irrespectively of chosen drug we observed similar effect for PWV drop. Reduction of arterial stiffness as a result of antihypertensive therapy is strongly connected with shear stress increase that is secondary to blood flow velocity growth and changes in connective tissue metabolism.

[Hypertrophic cardiomyopathy with midventricular obstruction of the left ventricle (MVO)--case report]

A 76-year old woman with a history of stage 3 arterial hypertension, paroxysmal atrial fibrillation, hypercholesterolemia and type 2 diabetes mellitus. Ventricular tachycardia was the first clinical manifestation of the disease. Echocardiography revealed hypertrophic cardiomyopathy with a high intraventricular gradient of 47 mmHg and midventricular obstruction at the level of the papillary muscles (the lumen of the left ventricle was 1-2 mm during systole). No ventricular aneurysm was found but the ventricle was elongated and dilated in the periapical part where systolic function was decreased but synchronized in time. Coronary angiograms showed no narrowing of coronary arteries. A single-chamber cardioverter-defibrillator (ICD, implantable cardioverter-defibrillator) was implanted to prevent sudden cardiac death. Modified-release metoprolol and amiodarone were administered in antiarrhythmic therapy. This case represents a rare kind of hypertrophic cardiomyopathy in an elderly woman which is characterized by midventricular obstruction.

[Atypical causes of myocardial infarction--Kounis syndrome]

The first reports about correlation between acute coronary syndromes and allergic reactions were originally published in 1950 and involved the use of penicillin. In 1991, Kounis and Zavras described the case of an allergic reaction which led to a myocardial infarction. Kounis syndrome is defined as an acute coronary syndrome which occurs during the course of an allergic reaction, and is caused by the contraction of the epicardial artery or the destabilization of the atherosclerotic plaque. Both of these processes are the consequence of a violent allergic reaction and the release of inflammatory markers such as histamine, proteolytic enzymes, and the products of arachidonic acid metabolism.