Ambulatory blood pressure monitoring in resistant hypertension

ABPM constitutes a valuable tool in the diagnosis of RH. The identification of white coat RH and masked hypertension (which may fulfill or not the definition of RH) is of great importance in the clinical management of such patients. Moreover, the various ABPM components such as average BP values, circadian BP variability patterns, and ambulatory BP-derived indices, such as ambulatory arterial stiffness index (AASI), add significantly to the risk stratification of RH. Lastly, ABPM may indicate the need for implementation of specific therapeutic strategies, such as chronotherapy, that is, administration-time dependent therapy, and the evaluation of their efficacy.

Subendocardial viability ratio as an index of impaired coronary flow reserve in hypertensives without significant coronary artery stenoses

Subendocardial viability ratio (SEVR), calculated through pulse wave analysis, is an index of myocardial oxygen supply and demand. Our aim was to evaluate the relationship between coronary flow reserve (CFR) and SEVR in 36 consecutive untreated hypertensives (aged 57.9 years, 12 males, all Caucasian) with indications of myocardial ischaemia and normal coronary arteries in coronary angiography. CFR was calculated by a 0.014-inch Doppler guidewire (Flowire, Volcano, San Diego, CA, USA) in response to bolus intracoronary administration of adenosine (30-60 μg). SEVR was calculated by radial applanation tonometry, while diastolic function was evaluated by means of transmitral flow and tissue Doppler imaging. Hypertensive patients with low CFR (n=24) compared with those with normal CFR (n=12) exhibited significantly decreased SEVR by 24.5% (P=0.002). In hypertensives with low CFR, CFR was correlated with SEVR (r=0.651, P=0.001). After applying multivariate linear regression analysis, age, left ventricular mass index, Em/Am, 24-h diastolic blood pressure (BP) and SEVR turned out to be the only independent predictors of CFR (adjusted R(2)=0.718). Estimation of SEVR by using applanation tonometry may provide a reliable tool for the assessment of coronary microcirculation in essential hypertensives with indications of myocardial ischaemia and normal coronary arteries.

Prevalence, clinical correlates and treatment of permanent atrial fibrillation among the elderly: insights from the first prospective population-based study in rural Greece

To investigate the prevalence of permanent atrial fibrillation (AF), its clinical associated conditions and treatment status in the elderly population in rural Greece. 720 people (46.1% males) older than 65 years (mean age: 72.5 +/- 5.7 years) living in four villages in rural Greece were screened with an electrocardiogram (response rate: 90.5%) for the presence of permanent AF. They underwent a physical examination, including blood pressure (BP) measurement, and body mass index (BMI) calculation, in addition to an interview about their medical history, physical activity, smoking habits, alcohol consumption and medication use. Subjects with AF for whom anticoagulants were contraindicated were identified and stroke risk stratification was performed using the CHADS2 algorithm. The prevalence of permanent AF was 5% (6.6% among men and 3.6% among women) and it increased with age. In the entire population, ECG evidence of myocardial ischaemia and ventricular premature beats were independently associated with the presence of permanent AF (OR 5.266; 95% CI 2.22-12.49, P = 0.0001 and OR 2.61; 95% CI 1.059-6.432, P = 0.037, respectively), while female sex was independently associated with the absence of the AF (OR 0.327; CI 0.147-0.729, P = 0.006). From those patients who were eligible for anticoagulation, 40.6% were treated with anticoagulants, 34.3% were given antiplatelets therapy and the rest received no antithrombotic treatment. This is the first prospective study demonstrating the prevalence, clinical correlates and treatment status of permanent AF in Greece. These results confirm the high prevalence of permanent AF among the elderly and underscore the issue regarding anticoagulants underutilization.

ADMA, C-reactive protein, and albuminuria in untreated essential hypertension: a cross-sectional study

BACKGROUND

Asymmetric dimethylarginine (ADMA) and subclinical inflammation are associated with atherosclerosis progression, whereas microalbuminuria is an established index of hypertensive organ damage.

STUDY DESIGN

Cross-sectional.

SETTING & PARTICIPANTS

In an outpatient hypertensive unit, 296 nondiabetic and untreated participants with hypertension were studied. Participants with atherosclerotic cardiovascular disease, severe valvulopathy, congestive heart failure, presence of neoplastic or other concurrent systemic disease, atrial fibrillation, serum creatinine level > 1.5 mg/dL in men and > 1.4 mg/dL in women, and urinary albumin excretion > 300 mg/24 h were excluded.

PREDICTORS

ADMA and high-sensitivity C-reactive protein (hs-CRP) levels.

OUTCOME VARIABLE

Albuminuria assessed using albumin-creatinine ratio (ACR).

MEASUREMENTS

Participants underwent ambulatory blood pressure monitoring, echocardiography, routine assessment of metabolic profile, ADMA, and hs-CRP, whereas ACR was determined as the mean of 3 values in nonconsecutive morning spot urine samples.

RESULTS

64 participants had an ACR of 30-300 mg/g. Stratification based on ADMA level showed that participants with hypertension in quartile [Q] 4 compared with those in Q3, Q2, and Q1 showed the highest ACRs (53.2 vs 31.2 vs 30.4 vs 16.7 mg/g; P < 0.008 for all). Moreover, stratification based on hs-CRP level showed that participants with hypertension in Q4 (69.8% had microalbuminuria) showed the highest ACRs (72.2 vs 25.6, 16.2, and 19.2 mg/g for Q3, Q2, and Q1, respectively; P < 0.008 for all). Stepwise regression analysis showed that age, 24-hour systolic blood pressure, hs-CRP level, ADMA level, and the interaction of hs-CRP with ADMA were independent predictors of ACR (R(2) = 0.674; P < 0.001).

LIMITATIONS

Cross-sectional study.

CONCLUSIONS

In patients with untreated essential hypertension, increased hs-CRP and ADMA levels are associated with microalbuminuria, suggesting the involvement of inflammation and endothelial dysfunction in vascular and kidney damage.

Leontio Lyceum ALbuminuria (3L Study) epidemiological study: aims, design and preliminary findings

INTRODUCTION

The significance of microalbuminuria (MA) in paediatric essential hypertension has yet to be established. The Leontio Lyceum ALbuminuria Study (3L Study) was designed to determine the prevalence of MA among Greek schoolchildren and to evaluate these rates in relation to the children's anthropometric and lifestyle characteristics, and dietary habits.

METHODS

During April 2009, 498 students from the Leontio Lyceum, aged 12-17 years (7th-12th grade), were asked to participate in the 3L Study. For each child a questionnaire was completed that was developed for the purposes of the study to retrieve information on socio-demographic and lifestyle characteristics, as well as dietary habits (through a semi-quantitative Food Frequency Questionnaire), and physical activity status. Overweight and obesity were defined using the international body mass index cut-off points established for children and young people. Office blood pressure (BP) was measured on two different occasions and those students who had BP >95th percentile for gender, age and height on both occasions were considered as hypertensives. Microalbuminuria was determined as albumin to creatinine ratio >or=22 mg/g in boys and >or=31 mg/g in girls in a morning spot urine sample using a quantitative assay (DCA 2000).

RESULTS

The prevalence of MA was found to be 12.9% and that of childhood hypertension 5.2%. The prevalence of overweight status was 25.8% and 5.8% of the students were classified as obese. Low physical activity was reported by 7% of boys and girls, while 46.5% of the students reported participation in vigorous physical activities during a normal week. Based on the KIDMED score of each student, only 6% of them were classified as high adherers to a Mediterranean diet and 41.9% were classified as having very low diet quality.

CONCLUSIONS

In this paper we present the aims, design and preliminary results of an epidemiological study on MA, hypertension, increased body size and lifestyle characteristics among Greek schoolchildren.

Myocardial and aortic stiffening in the early course of primary aldosteronism

BACKGROUND

Primary aldosteronism (PA) has been experimentally and clinically linked to myocardial and vascular fibrosis, and it has been further associated with left ventricular (LV) structural adaptations.

HYPOTHESIS

Functional cardiovascular adaptations in hypertensive patients with PA precede structural alterations in the early stages of the disease.

METHODS

We studied 17 hypertensive subjects with a recent diagnosis of PA (10 male patients, aged approximately 55 y, with office blood pressure [BP] of 137/88 mm Hg), and 30 essential hypertensives matched for age, sex, office BP levels, treatment status, and LV mass index (LVMI). Apart from standard 2-Dimensional (2-D) and conventional Doppler parameters, tissue Doppler imaging (TDI) methodology was used to assess LV diastolic function; averaging early and late diastolic mitral annular peak velocities (Emav/, Amav, Emav/Amav ratio) from 4 separate sites of measurement (septal, lateral, anterior, and inferior walls). Aortic stiffness was evaluated by means of carotid-femoral pulse wave velocity (cf-PWV) measurements.

RESULTS

Although transmitral E/A ratio was similar in both groups (0.95+/-0.26 versus 0.98+/-0.24, p=0.66), hypertensive subjects with PA compared with essential hypertensives are characterized by significantly higher relative wall thickness (0.50+/-0.07 versus 0.41+/-0.06, p<or=0.001), decreased values of Emav (7+/-1.7 versus 8.1+/-1.8 cm/s, p=0.048), and Emav/Amav ratio (0.63+/-0.16 versus 0.77+/-0.17, p=0.015). The higher PWV in the PA population failed to reach statistical significance (8.5+/-1.6 versus 7.9+/-0.9 msec, p=0.19).

CONCLUSION

Our study demonstrates altered LV geometry and TDI-revealed diastolic dysfunction in hypertensives with PA compared with demographically- and LVMI-matched essential hypertensives. Furthermore, the increased aortic stiffening in PA patients failed to reach statistical significance.

Association of obstructive sleep apnea with urinary albumin excretion in essential hypertension: a cross-sectional study

BACKGROUND

Microalbuminuria reflects a state of widespread vascular dysfunction, whereas obstructive sleep apnea (OSA) further promotes atherosclerotic damage in hypertension.

STUDY DESIGN

Cross-sectional.

SETTING & PARTICIPANTS

In an outpatient hypertensive unit, 62 untreated hypertensive patients (aged 48 +/- 7 years; office blood pressure [BP], 151 +/- 8/97 +/- 7 mm Hg) with OSA and 70 hypertensive patients without OSA (apnea hypopnea index [AHI] < or = 5) matched for age, sex, smoking status, body mass index, and 24-hour pulse pressure were studied.

PREDICTOR VARIABLE

Hypertension and OSA compared with hypertension without OSA. OSA defined as AHI greater than 5, documented by polysomnography.

OUTCOME VARIABLE

Albuminuria assessed by urinary albumin-creatinine ratio (ACR).

MEASUREMENTS

Participants underwent polysomnography, ambulatory BP monitoring, echocardiography, routine metabolic profile assessment, and glomerular filtration rate estimation, whereas ACR was measured from 2 nonconsecutive morning spot urine samples.

RESULTS

Hypertensive patients with OSA compared with those without OSA showed increased 24-hour diastolic BP (87 +/- 7 versus 85 +/- 7 mm Hg; P = 0.03) and nighttime pulse pressure (50 +/- 10 versus 45 +/- 10 mm Hg; P = 0.008), but did not differ regarding metabolic profile and estimated glomerular filtration rate. Albuminuria was greater by 57% in patients with OSA compared with those without OSA: log(10)ACR, 1.1 +/- 0.2 versus 0.7 +/- 0.4 mg/g; P < 0.001). In the entire study population, log10(ACR) correlated with log10(AHI) (r = 0.35; P < 0.001), minimum oxygen saturation during sleep (r = -0.33; P < 0.001), 24-hour pulse pressure (r = 0.38; P < 0.001), and nighttime pulse pressure (r = 0.21; P =0 .01). In a multivariable linear regression model, independent predictors of ACR were AHI (beta = 0.36; P < 0.001) and 24-hour pulse pressure (beta = 0.25; P = 0.01).

LIMITATIONS

Cross-sectional study.

CONCLUSIONS

Albuminuria increases within the normal range in hypertensive individuals with OSA compared with those without OSA proportionally to OSA severity independently of confounders. The association of upper-airway dysfunction with albuminuria and pulsatile hemodynamic load may provide an explanatory mechanism for the OSA-related risk in hypertension.

Low-grade inflammation and hypoadiponectinaemia have an additive detrimental effect on aortic stiffness in essential hypertensive patients

AIMS

In this study, we investigated the combined effect of increased high-sensitivity C-reactive protein (hs-C-reactive protein) and hypoadiponectinaemia on aortic stiffness in essential hypertensive subjects.

METHODS AND RESULTS

A total of 267 untreated patients with stage I-II essential hypertension underwent ambulatory BP and carotid-femoral pulse wave velocity (c-f PWV) evaluation. The distributions of hs-C-reactive protein and adiponectin were split by the median (1.3 mg/L and 7.8 microg/mL, respectively) and accordingly subjects were stratified into those with high and low values. Patients with high (n = 134) compared with those with low hs-C-reactive protein (n = 133) values exhibited greater c-f PWV levels (by 0.8 m/s, P < 0.0001), whereas patients with low (n = 133) compared with those with high (n = 134) adiponectin levels had higher c-f PWV (by 0.9 m/s, P < 0.0001). Stepwise regression analysis revealed that age, 24 h systolic BP, hs-C-reactive protein and adiponectin were independent predictors of arterial stiffness. In patients with low hs-C-reactive protein, hypoadiponectinaemia (n = 46) compared with high adiponectin (n = 87) was accompanied by increased c-f PWV (by 0.8 m/s, P < 0.0001). Similarly in patients with high hs-C-reactive protein, hypoadiponectinaemia (n = 84) compared with high adiponectin (n = 50) was related to heightened c-f PWV (by 0.7 m/s, P = 0.008).

CONCLUSION

In essential hypertension, pronounced low-grade inflammation in conjunction with hypoadiponectinaemia exerts an additive detrimental effect on aortic stiffness, accelerating the vascular ageing process.

The incremental effect of obstructive sleep apnoea syndrome on arterial stiffness in newly diagnosed essential hypertensive subjects

OBJECTIVE

Although obstructive sleep apnoea syndrome (OSAS) is accompanied by an increased atherosclerotic cardiovascular disease burden, its relationship with arterial stiffness is not yet well determined. We investigated whether essential hypertensive individuals with OSAS are characterized by increased arterial stiffness.

METHODS

Our study population consisted of 46 consecutive patients with newly diagnosed untreated stage I-II essential hypertension suffering from OSAS (35 men, aged 49 +/- 8 years) and 53 hypertensive individuals without OSAS, matched for age, sex, and smoking status. All subjects underwent polysomnography, echocardiography and aortic stiffness evaluation by means of carotid-femoral pulse wave velocity (c-fPWV) measurements.

RESULTS

Hypertensive subjects with OSAS [apnoea/hypopnoea index (AHI)>or =5] compared with hypertensive subjects without OSAS (AHI < 5) demonstrated increased levels of body mass index (31.4 +/- 4 versus 29.3 +/- 4 kg/m2, P = 0.015), office systolic/diastolic blood pressure (151/99 versus 145/94 mmHg, respectively, P < 0.05, for both cases) and relative wall thickness (RWT; 0.46 +/- 0.06 versus 0.42 +/- 0.07, P=0.010). Hypertensive subjects with OSAS compared with those without OSAS had significantly increased c-fPWV by 9% (8.56 +/- 0.49 versus 7.85 +/- 0.93 m/s, P=0.001) and this difference remained significant even after adjustment for confounders (P=0.04). In the total study population, c-fPWV was correlated with age (r=0.35, P=0.015), office systolic blood pressure (r=0.30, P=0.007), RWT (r=0.30, P=0.03), logAHI (r=0.389, P=0.0001) and minimum oxygen saturation (r=-0.418, P=0.0001).

CONCLUSIONS

OSAS has a significant incremental effect on aortic stiffening in the setting of middle-aged essential hypertensive subjects. This finding suggests that the presence of OSAS in a hypertensive patient accelerates vascular damage, increasing cardiovascular risk.

Diverse associations of microalbuminuria with C-reactive protein, interleukin-18 and soluble CD 40 ligand in male essential hypertensive subjects

BACKGROUND

Microalbuminuria (MA) and low-grade inflammation constitute emerging markers of subclinical atherosclerosis. We investigated whether urinary albumin excretion, expressed as the albumin-to-creatinine ratio (ACR), is associated with high sensitivity C-reactive protein (hs-CRP), interleukin (IL)-18, and soluble CD40 ligand (sCD40L), in hypertensive subjects.

METHODS

The study population consisted of 108 nondiabetic male patients with newly diagnosed untreated stage I to II essential hypertension (aged 44.6 years, office blood pressure [BP] 148/95 mm Hg). According to ACR values determined as the average of two nonconsecutive overnight spot urine samples, subjects were divided into microalbuminurics (n = 28) (mean ACR = 30 to 300 mg/g) and normoalbuminurics (n = 80) (mean ACR <30 mg/g).

RESULTS

Although microalbuminurics as compared to normoalbuminuric hypertensives had greater hs-CRP levels (2.55 +/- 1.18 v 1.45 +/- 0.52 mg/L, P < .0001), independently of confounding factors, these two groups did not differ regarding IL-18 and sCD40L values (P = not significant [NS] for both cases). In the entire population, ACR exhibited a positive correlation with hs-CRP (r = 0.623, P < .0001), whereas there was no association with both IL-18 and sCD40L (P = NS for both cases). When multiple linear regression analysis was performed, it was revealed that age, body mass index, office systolic BP, total cholesterol, and hs-CRP levels were significant independent predictors of the ACR (P < .05).

CONCLUSIONS

In essential hypertensive subjects, MA is accompanied by elevated hs-CRP levels, but not by augmented IL-18 and sCD40L concentrations, suggesting activation of different inflammatory pathways in the progression of renal and cardiovascular atherosclerotic disease. The pathophysiologic mechanisms of these associations remain to be further elucidated in future studies.