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.

Relationship of metabolic syndrome with pulse pressure in patients with essential hypertension.

BACKGROUND: Pulse pressure is largely dependent on arterial stiffness. Recent studies have documented reduced large artery compliance in nondiabetic subjects with metabolic syndrome (MS). The aim of our study was to analyze, in a group of patients with essential hypertension and without diabetes mellitus, the influence of MS on clinic and 24-h pulse pressures. METHODS: A total of 528 hypertensive subjects, aged 18 to 72 years, who were free of cardiovascular and renal diseases were enrolled. Of the subjects, 41% had MS. In all subjects routine blood chemistry, echocardiographic examination, and 24-h ambulatory blood pressure monitoring were performed. RESULTS: When compared with subjects without MS, hypertensive patients with MS exhibited more elevated clinic pulse pressures (66 +/- 16 v .58 +/- 14 mm Hg; P < .00001) and 24-h (51 +/- 9 v .48 +/- 7 mm Hg; P = .00001). These results held even after correction for age, sex, stroke volume, mean pressures, and total cholesterol. The regression line relating PP with age was steeper in patients with MS than in those without MS. Multivariate regression models confirmed that the relationships of MS with clinic (beta = 0.12; P = .003) and 24-h PP (beta = 0.11; P = .01) were independent from several confounding factors. CONCLUSIONS: The elevated levels of clinic and 24-h PP observed in hypertensive patients with MS may reflect increased large arteries stiffness and may therefore contribute to explain the enhanced cardiovascular risk associated with MS.

Influence of the metabolic syndrome on aortic stiffness in never treated hypertensive patients.

BACKGROUND AND AIM: Metabolic syndrome (MS) carries an increased risk for cardiovascular events and there is a growing awareness that large artery stiffening is a powerful predictor of cardiovascular morbidity and mortality. Little is known about the relationship of MS with aortic stiffness. The aim of our study was to analyze, in patients with essential hypertension, the influence of MS, defined according to the criteria proposed by the Third Report of the National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (NCEP-ATP III), on carotid-femoral pulse wave velocity (PWV), a measure of aortic stiffness. METHODS: Ninety-three untreated essential hypertensives, aged between 23 and 61 years, without diabetes mellitus, were studied. All subjects underwent routine blood chemistry, oral glucose tolerance test with glucose and insulin determinations, albumin excretion rate (AER) measurement, 24-h ambulatory blood pressure monitoring, and measurement of carotid-femoral PWV, by means of a computerized method. RESULTS: Patients with MS (n = 28) showed higher age-adjusted carotid-femoral PWV (10.1 +/- 1.4 vs 9.3 +/- 1.4 m/s; p = 0.01) when compared to subjects without MS. This difference held after controlling for gender and for 24-h mean blood pressure (MBP) (p = 0.02) and lost its statistical significance after further adjustment for AER. In a multiple regression model, excluding the individual components of MS, in which metabolic syndrome was added along with age, gender, smoking habit, LDL cholesterol, HOMA index, 24-h MBP and 24-h heart rate, MS remained independently associated with carotid-femoral PWV (beta = 0.29; p = 0.002). The statistical significance of this association disappeared after the inclusion into this model of AER. CONCLUSIONS: Metabolic syndrome is associated with an increased aortic stiffness. Main explanatory factors of this association are age, systolic blood pressure and albumin excretion rate.

Renal plasma flow, filtration fraction and microalbuminuria in hypertensive patients: effects of chronic smoking.

INTRODUCTION: Albumin excretion rate is usually increased in people who smoke, but the physiological basis of this phenomenon is not fully understood. METHODS: The effect of chronic smoking on renal haemodynamics was studied in a cohort of 66 men. Twenty-seven were smokers and 36 were hypertensive. In all subjects, the albumin excretion rate was evaluated; in hypertensive patients, a renoscintigraphic evaluation of renal plasma flow and glomerular filtration were carried out and the filtration fraction was calculated. RESULTS: The hypertensive smoking population presented an increased urinary albumin excretion rate in comparison with hypertensive non-smoking patients. No significant differences were found for the mean values of renal plasma flow, the glomerular filtration rate and the filtration fraction between hypertensive smokers and hypertensive non-smoking patients. CONCLUSIONS: In hypertensive patients, smoking does not modify typical renal haemodynamic changes of arterial hypertension; however, it significantly increases the albumin excretion rate.

Usefulness of microalbuminuria in cardiovascular risk stratification of essential hypertensive patients.

BACKGROUND/AIMS: To evaluate the influence of microalbuminuria (albumin excretion rate--AER) determination and echocardiography (ECHO) on cardiovascular risk stratification, initially performed according the 1999 WHO/ISH guidelines by using only routine diagnostic procedures with or without fundal examination. METHODS: 312 essential hypertensives attending our institution were studied retrospectively. Cardiovascular risk was assessed in a semiquantitative way using four categories of absolute cardiovascular disease risk (low, medium, high and very high risk), as proposed by the 1999 WHO/ISH guidelines, on the basis of data on the average 10-year risk of cardiovascular events among participants in the Framingham Study. RESULTS: Without the retinal data, estimating the level of global cardiovascular risk on the basis of routine work-up alone, 14% were classified as low-risk patients, 48% were as medium-risk, 20% as high-risk and 18% at very-high-risk patients. The combined use of AER and ECHO, in line with the newer ESH-ESC guidelines, determined a statistically significant reclassification of the hypertensive patients. Only 10% remained in the low-risk category, 28% were classified in the medium-, 42% in the high- and 20% in the very-high-risk classes. The overall percentage of patients that changed risk stratum (mostly shifting from the medium- to the high-risk class) was significantly different from the proportion of subjects reclassified after the addition of either microalbuminuria or echocardiography alone. No change in the distribution of risk categories was observed when AER assay and ECHO were added to routine procedures including funduscopic examination. CONCLUSIONS: Considering the questionable prognostic value of qualitative retinal examination, our results suggest that cardiovascular risk evaluation based only on simple routine work-up, ignoring the information provided by AER determination and ECHO, may underestimate the level of absolute risk.

Relationships between ambulatory white coat effect and left ventricular mass in arterial hypertension.

The aim of our study was to analyze, in a group of 296 essential hypertensives, the relationship between left ventricular mass (LVM) and ambulatory white coat effect (WCE); that is the difference between the elevation of the first measurements of ambulatory blood pressure monitoring and the mean daytime pressure. The study population was separated into two groups according to the median of the WCE. The LVM was greater in the groups with higher systolic and diastolic ambulatory WCE. The significant association between ambulatory WCE and LVM was confirmed by the results of multiple regression analysis, suggesting that ambulatory WCE may not be an innocent phenomenon.

Insulin resistance and glomerular hemodynamics in essential hypertension.

BACKGROUND: Arterial hypertension is an important cause of end-stage renal failure. Insulin has been shown to modify glomerular hemodynamics in hypertensive subjects. The aim of this work, therefore, was to observe the relationships between renal hemodynamics and insulin resistance in arterial hypertension. METHODS: Sixty-two non-diabetic hypertensive patients and 25 healthy normal subjects were studied. Renal plasma flow and the glomerular filtration fraction were determined by renoscintigraphy and the insulin sensitivity by an oral glucose test. RESULTS: Renal plasma flow in hypertensive subjects was lower than expected and was related to pressure values, whereas the mean glomerular filtration rates were not different in the two groups. In most patients the filtration fraction was higher than expected. A lower glomerular filtration rate and lower filtration fraction were found in patients with higher insulin resistance. CONCLUSIONS: The progressive decrease of glomerular function in subjects with hypertension is linked with insulin-resistance.

Value of home blood pressures as predictor of target organ damage in mild arterial hypertension.

BACKGROUND: Home blood pressure measurement has gained increasing importance for the management of hypertensive patients. The aim of our study was to compare levels of clinic (CBP), ambulatory (ABP), and home blood pressure (HBP) measurements, and their relationships with various indexes of target organ damage in I-II grade essential hypertension. DESIGN AND METHODS: Thirty-eight essential hypertensives underwent evaluation of clinic, ambulatory and home blood pressures. Each patient recorded HBP for 2 days with a digital BP monitor three times daily, the first time on the same day during which ABP monitoring was simultaneously performed. Moreover, in all subjects electrocardiogram recording, echocardiographic study, microalbuminuria assay and fundus oculi examination were obtained. RESULTS: The average HBPs obtained on the first day, in particular systolic values, were quite similar to mean daytime ambulatory BP recorded on the same day. Clinic BP, both systolic and diastolic, showed no significant correlation with left ventricular mass index (LVMI) and with albumin excretion rate (AER), whereas a correlation barely significant was observed with an index of global target organ damage (GTODi), including cardiac, renal and retinal parameters. On the contrary, home blood pressures, especially those recorded on the second day, correlated significantly, and more tightly than clinic BP, with LVMI, AER and GTODi. CONCLUSIONS: Our study seems to justify the adoption of home BP monitoring in the management of hypertensive patients, as a useful complement to clinical readings, and may provide additional prognostic information.