Association of resistin with urinary albumin excretion in nondiabetic patients with essential hypertension.

BACKGROUND: Evidence suggests that resistin, a recently described protein, is associated with subclinical atherosclerosis in different clinical settings. In this study, we investigated the relationship of increased resistin levels with urinary albumin excretion, expressed as the albumin-to-creatinine ratio (ACR), an established index of diffuse vascular damage, in hypertensives. METHODS: Our population consisted of 132 untreated nondiabetic subjects with stage I-II essential hypertension (49 males, mean age = 54 years, mean office blood pressure (BP) = 159/100 mm Hg). In all patients, ACR was determined as the average of three nonconsecutive morning spot urine samples, and venous blood sampling was performed for estimation of resistin concentrations. The distribution of resistin was split by the median (4.63 ng/ml), and accordingly, subjects were stratified into those with high and low values. RESULTS: Hypertensive patients with high (n = 66) compared to those with low resistin (n = 66) exhibited higher ACR values (21.8 + or - 15.3 vs. 10.3 + or - 3.8 mg/g, P < 0.01), even after adjustment for confounders. In the total population, resistin was associated with 24-h systolic BP (r = 0.244, P < 0.05), serum creatinine (r = 0.311, P = 0.007), and ACR (r = 0.499, P < 0.01). Multiple regression analysis revealed that age (b = 0.193, P = 0.02), body mass index (b = 0.237, P = 0.02), 24-h systolic BP (b = 0.338, P < 0.0001), 24-h heart rate (b = 0.169, P = 0.04), and resistin (b = 0.77, P < 0.01) were independently associated with ACR (R(2) = 0.471, P < 0.01). CONCLUSIONS: Hypertensive subjects with augmented resistin levels exhibit higher albuminuria, independently of established risk factors. Moreover, the association of resistin with ACR suggests a link between resistin and microvascular disease in the early stages of essential hypertension.

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.

Impact of waist circumference on cardiac phenotype in hypertensives according to gender.

Our aim was to assess the differential effect of waist circumference on left-ventricular (LV) structural and functional alterations, in hypertensive males and females. One thousand seven hundred and eighty nine consecutive, nondiabetic, essential hypertensives (aged 55.8 +/- 13.5 years, 966 females), included in the 3H Study, an ongoing registry of hypertension-related-target-organ damage, were classified to obese and nonobese groups according to Adult Treatment Panel III criteria. All participants underwent complete echocardiographic study including LV diastolic function evaluation by means of conventional and tissue Doppler imaging (TDI) methods, averaging early and late diastolic mitral annular peak velocities (Em, Am, Em/Am) from four separate sites of measurement. Hypertensive obese women compared with nonobese exhibited significantly greater LV mass index and prevalence of LV hypertrophy (by 5.5 g/m(2), P = 0.003, and 8.8%, P = 0.005, respectively), while such differences were not present among men. Obese women compared to nonobese ones were accompanied by lower transmitral E/A (by 0.08, P < 0.001), TDI-derived Em/Am (by 0.12, P < 0.001), and higher E/Em ratio (by 0.8, P = 0.016). In contrast, hypertensive obese men compared to nonobese ones exhibited lower E and Em (by 0.04 m/s and 0.6 cm/s, both P < 0.05). A significant interaction between sex and abdominal obesity was observed only regarding TDI-derived Am and Em/Am. Furthermore, waist circumference was a predictor of E/A (beta = -0.097, P = 0.002) and Em/Am (beta = -0.116, P = 0.001), independently of body size, in females but not in males. The adverse effect of abdominal obesity on LV alterations is more pronounced among female hypertensives, suggesting that routine measurement of waist circumference provides additional information on cardiac phenotype especially in women.

Exercise blood pressure response, albuminuria, and arterial stiffness in hypertension.

BACKGROUND: A hypertensive response to exercise is associated with high cardiovascular risk, whereas the data about its relation to surrogates of subclinical atherosclerosis are scarce. We investigated the relationships of a hypertensive response to exercise with urinary albumin excretion and arterial stiffness in hypertensives. METHODS: There were 171 untreated males (mean age 52 years, all Caucasian) with stage I-II essential hypertension and a negative treadmill exercise test divided into those with a hypertensive response to exercise (n=48) (peak exercise systolic blood pressure > or =210 mm Hg) and to those with normal blood pressure response (n=123). Albumin-to-creatinine ratio values were determined as the mean of 3 nonconsecutive morning spot urine samples, and arterial stiffness was evaluated on the basis of carotid-to-femoral pulse wave velocity. RESULTS: Patients with a hypertensive response to exercise compared with those with normal blood pressure response exhibited greater log albumin-to-creatinine ratio (1.52+/-0.59 vs 0.97+/-0.33 mg/g) and higher pulse wave velocity (8.7+/-1.6 vs 7.7+/-1.2 m/s), independent of potentially confounding demographic and clinical factors. Resting systolic blood pressure (odds ratio [OR] 1.11, 95% confidence interval [CI], 1.06-1.16), body mass index (OR 1.12, 95% CI, 1.02-1.23), resting heart rate (OR 0.96, 95% CI, 0.93-0.99), and albumin-to-creatinine ratio (OR 7.45, 95% CI, 2.54-21.83) were independently associated with a hypertensive response to exercise. CONCLUSION: A hypertensive response to exercise is related to augmented albumin-to-creatinine ratio and arterial stiffness, reflecting accelerated subclinical atherosclerosis. The association of albumin excretion with exercise blood pressure response suggests that albuminuria constitutes an important factor in the interpretation of the hypertensive response to exercise-associated risk.

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.

Evidence for no global effect of metabolic syndrome per se on early hypertensive sequelae.

OBJECTIVE: In the present study we assessed the impact of metabolic syndrome (MS) and its components on markers of cardiovascular and renal damage in a population of essential hypertensives. METHODS: A total of 651 consecutive, untreated and non-diabetic hypertensives (age 54 +/- 12 years, 340 males) who were included in the 3H Study, an ongoing registry of hypertension-related target organ damage, were considered for analysis. Left ventricular mass was indexed both for body surface area (LVMBSA) and for height2.7 (LVMheight2.7). Diastolic function was estimated by means of both conventional and tissue Doppler imaging (TDI) methods. Arterial stiffness was evaluated on the basis of carotid to femoral pulse wave velocity (c-f PWV) and microalbuminuria (MA) as albumin to creatinine ratio (ACR) 22-300 mg/g in men and 31-300 mg/g in women in two non-consecutive morning spot urine samples. RESULTS: MS (Adult Treatment Panel III criteria) was present in 201 hypertensives (30.9%). Hypertensives with MS had increased logACR (by 10%, P = 0.01) and higher prevalence of MA (17 versus 8%, P < 0.001). Both groups exhibited similar values of LVMBSA, transmitral and TDI-derived indexes and c-f PWV (NS for all) while LVMheight2.7 was significantly higher in hypertensives with MS (by 2.6 g/m2.7, P = 0.023). Multiple regression analysis revealed that MS was an independent predictor only of logACR (beta = 0.110, P = 0.007) and MA (odds ratio = 2.577, P < 0.001), while components of blood pressure affected all studied indices of organ damage. CONCLUSIONS: MS per se does not deteriorate cardiac adaptations and aortic stiffness beyond haemodynamic load in hypertension. The MS-related unfavourable effect is limited to the level of the glomerulus.

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.