老年高血压患者动态动脉硬化指数与估测肾小球滤过率的相关性

目的 观察老年高血压患者动态动脉硬化指数（ AASI）与估测肾小球滤过率（eGFR）的相关性,探讨以AASI大小反应的动脉硬化程度在老年高血压患者肾功能受损中的作用.方法 218例行24小时动态血压检测血肌酐水平基本正常的老年高血压患者,根据文献方法计算AASI,以AASI≤0.55或AASI＞ 0.55分为两组,比较各组间eGFR的差异,以及运用Pearson相关分析及多元线性回归分析eGFR与AASI及年龄、平均收缩压、平均舒张压、血肌酐水平等因素的相关性.结果 与AASI≤0.55组比较,在AASI＞ 0.55组中eGFR值明显降低（P＜0.001）.Pearson 相关分析显示,eGFR与AASI呈负相关（r=-0.624,P＜0.001）,控制年龄、平均收缩压、平均舒张压、平均脉压、血肌酐水平等因素后,偏相关分析显示,eGFR仍与AASI显著相关（r=-0.343,P＜0.001）.多元逐步回归分析显示,eGFR 与肌酐水平、AASI独立相关,标准化偏回归系数分别为-0.770、-0.240,P＜0.001.结论 在老年高血压患者,AASI与eGFR呈独立负相关,AASI值增加是老年高血压患者早期肾功减退的独立危险因素.     

Increased ambulatory arterial stiffness index is associated with target organ damage in primary hypertension

Increased arterial stiffness has been shown to predict cardiovascular mortality in patients with primary hypertension. Asymptomatic organ damage is known to precede cardiovascular events. We investigated the relationship between a recently proposed index of stiffness derived from ambulatory blood pressure (BP) and target organ damage in 188 untreated patients with primary hypertension. Ambulatory arterial stiffness index was defined as 1 minus the regression slope of diastolic over systolic BP readings obtained from 24-hour recordings. Albuminuria was measured as the albumin:creatinine ratio, left ventricular mass index was assessed by echocardiography, and carotid abnormalities were evaluated by ultrasonography. The prevalence of microalbuminuria, left ventricular hypertrophy (LVH), and carotid abnormalities was 12%, 38%, and 19%, respectively. Ambulatory arterial stiffness index was positively related to age, triglycerides, office and 24-hour systolic BP, 24-hour pulse pressure, urinary albumin excretion, and carotid intima-media thickness. Patients with microalbuminuria, carotid abnormalities, or LVH showed higher ambulatory arterial stiffness index as compared with those without it. After adjusting for confounding factors, each SD increase in ambulatory arterial stiffness index entails an &2 times higher risk of microalbuminuria, carotid abnormalities, and LVH and doubles the risk of the occurrence of >or=1 sign of organ damage. Ambulatory arterial stiffness index is associated with organ damage in patients with primary hypertension. These data strengthen the role of this index as a marker of risk and help to explain the high cardiovascular mortality reported in patients with high ambulatory arterial stiffness index.     

Mild renal dysfunction and renal vascular resistance in primary hypertension

BACKGROUND: Mild renal dysfunction (MRD) is an often overlooked but relatively common condition in patients with primary hypertension (PH), and is associated with high cardiovascular morbidity and mortality. Whether MRD is also associated with abnormalities in renal vascular resistance is currently unknown. METHODS: Two hundred ninety-one untreated patients with PH were studied. The MRD was defined as a creatinine clearance >or=60 mL/min but <90 mL/min (Cockcroft-Gault formula) or the presence of microalbuminuria. Albuminuria was measured as the albumin-to-creatinine ratio in first morning urine samples. Renal resistive index (RI) was evaluated by ultrasound Doppler of the interlobar arteries. RESULTS: The prevalence of MRD in our cohort was 63%. Patients with MRD were older, had higher mean blood pressure (BP), pulse pressure, and total cholesterol, longer history of hypertension, and were more likely to be men. Renal RI was positively related to female gender, age, systolic BP, pulse pressure, total cholesterol, albuminuria, and to carotid wall thickness and cross-sectional area, whereas it was inversely related to diastolic BP and creatinine clearance. Patients with the highest renal resistance (upper quartile, >or=0.63) showed a greater prevalence of renal dysfunction (P=.0005). After adjusting for age, pulse pressure, and LDL-cholesterol, we found that the risk of MRD increased twofold (P=.04) when renal RI was >or=0.63. CONCLUSIONS: A reduction in creatinine clearance and the presence of microalbuminuria are associated with increased renal vascular impedence, as well as with signs of extrarenal arterial stiffness.     

高血压和糖尿病患者动态动脉硬化指数与靶器官损害的相关性

目的 探讨高血压和糖尿病患者的动态动脉硬化指数（AASI）与肾脏损害及颈动脉内膜损伤的相关性.方法 筛选原发性高血压患者149例、2型糖尿病患者79例、高血压合并糖尿病患者98例,同期健康体检者48名作为对照组,分别行24h动态血压监测（ABPM）,尿白蛋白、尿肌酐测定及颈动脉内-中膜厚度（IMT）测量,计算出AASI,进行AASI与尿白蛋白/尿肌酐比值（ACR）及IMT等的相关性分析.结果 高血压组、糖尿病组、高血压合并糖尿病组与健康对照组比较,ACR值、微量白蛋白尿发生率、IMT、颈动脉异常发生率以及AASI差异均有统计学意义.两组间两两比较,高血压合并糖尿病组与高血压组、糖尿病组、健康对照组间差异均有统计学意义,高血压组、糖尿病组与健康对照组间差异均有统计学意义.多变量logistic分析显示,ASSI增高的独立相关危险因素是女性、年龄、高血压病史、糖尿病病史.结论 高血压、糖尿病患者的AASI与肾脏损害及颈动脉内膜损伤程度有明显相关性,高血压、糖尿病独立促进动脉硬化的进展.     

Mild hyperuricemia and subclinical renal damage in untreated primary hypertension

BACKGROUND: Subclinical renal damage and hyperuricemia are not uncommon in patients with primary hypertension. Whether mild hyperuricemia reflects a subclinical impairment of renal function or contributes to its development is currently debated. We investigated the relationship between serum uric-acid levels and the occurrence of early signs of kidney damage. METHODS: Four hundred eighteen patients with primary hypertension were studied. Albuminuria was measured as the albumin-to-creatinine ratio, and creatinine clearance was estimated by the formula of Cockcroft and Gault. Interlobar resistive index and renal abnormalities, ie, the renal volume-to-resistive index ratio, were evaluated by renal Doppler and ultrasound. RESULTS: Uric acid was directly related to resistive index (P = .007) in women and to albuminuria (P = .04) in men, and was inversely related to the renal volume-to-resistive index ratio in both men (P = .005) and women (P = .02). Patients with uric-acid levels above the median showed a higher prevalence of microalbuminuria (14% v 7%, P = .012) and of renal abnormalities (41% v 33%, P = .007). Moreover, when creatinine clearance was taken as a covariate, patients with increased uric-acid levels showed higher albuminuria and resistive indices, and a lower renal volume-to-resistive index ratio. Even after adjustment for several risk factors, each standard deviation increase in serum uric acid entailed a 69% higher risk of microalbuminuria, and a 39% greater risk of ultrasound detectable renal abnormalities. CONCLUSIONS: Mild hyperuricemia is associated with early signs of renal damage, ie, microalbuminuria and ultrasound-detectable abnormalities, regardless of the glomerular filtration rate in primary hypertension.     

高血压患者动态动脉硬化指数对靶器官损害的早期预测

目的:研究原发性高血压(EH)患者的动态动脉硬化指数(AASI)对靶器官损害的早期预测.方法:筛选无糖尿病和其他致动脉硬化性疾病的EH患者149例(EH组),以及同期健康体检者48例作为正常对照组,分别测定其体质指数、空腹血糖、血脂、肾功能,并行24 h动态血压监测及尿白蛋白/肌酐比值(ACR)测定、颈动脉内中膜厚度(IMT)测量,计算出AASI,最后进行AASI与ACR以及IMT等的相关性分析.结果:与正常对照组相比,EH组尿ACR、微量白蛋白尿发生率、IMT、颈动脉异常率以及AASI均增高(P＜0.05～0.01),且EH患者的AASI与ACR以及IMT呈显著正相关.结论:EH患者的AASI与肾脏损害及颈动脉内膜损伤程度相关,可作为动脉硬化程度的评估指标.     

老年高血压患者降压治疗后动态动脉僵硬度指数研究

目的 观测老年高血压患者降压治疗后动态动脉僵硬度指数（ambulatory arterial stiftness index，AASI）的结果及其对评估动脉硬化和预测心血管事件的作用。方法 观测99例住院老年高血压患者，男性87例；女性12例，平均年龄78．03±6．36岁。记录其在连续接受降血压治疗6个月后的相关资料（高密度脂蛋白检测，24小时动态血压测定，动态动脉僵硬度指数及脉压、脉压指数）并进行回顾性分析。结果动态动脉僵硬度指数与脉压指数呈中度正相关（r=0．381，P〈0．001），与高密度脂蛋白呈负相关（r=-0．252，P=0．013）。结论提示对于接受降压治疗的老年原发性高血压患者，动态动脉僵硬度指数可作为动脉硬化评估的参考指标，有望成为心血管危险的预测因子。     

Association of renal function with the ambulatory arterial stiffness index and pulse pressure in hypertensive patients

Arterial stiffness exemplified by the ambulatory arterial stiffness index (AASI) and pulse pressure (PP) predicts cardiovascular morbidity and mortality. The present cross-sectional study assessed the association of renal function with AASI and 24-h PP in hypertensive inpatients. Subjects included 948 hypertensive inpatients with drug treatment (mean age, 53.3 years; male, 67.1%). The AASI was defined as 1 minus the regression slope of diastolic over systolic blood pressure readings obtained from 24-h recordings. Renal function was evaluated by serum creatinine and urinary albumin excretion was expressed by the urinary albumin-to-urinary creatinine ratio (ACR), and estimated glomerular filtration rate (eGFR) was calculated by the modification of diet in renal disease formula and chronic kidney disease-epidemiology collaboration formula. As AASI and 24-h PP increased, serum creatinine concentrations and ACR increased, and eGFR decreased. Multiple linear regression showed that AASI and 24-h PP were associated with eGFR-EPI (B=-12.00, P=0.001 vs. B=-0.14, P=0.002) and ACR (B=0.56, P=0.004 vs. B=0.01, P=0.017) independent of other cardiovascular risk factors. After additional adjustment for 24-h PP, the association of AASI with eGFR-EPI had borderline significance (P=0.053), whereas the significant associations of 24-h PP with serum creatinine and ACR persisted (P=0.009 and P=0.006) after adjusting for confounding factors and AASI. Multiple logistic regression analysis showed that each s.d. increase in 24-h PP (that is, 13?mm?Hg) was associated with a higher risk of suffering from microalbuminuria (MA) by 39% (P=0.038) after additional adjustment for AASI. In conclusion, AASI is more closely associated with eGFR compared with 24-h PP in hypertensive inpatients. However, for MA 24-h PP is a better predictor.     

Loss of the nocturnal decline in blood pressure in subjects with essential hypertension and microalbuminuria

BACKGROUND: Microalbuminuria, a marker of early renal damage, predicts mortality in non-diabetic subjects. The loss of circadian blood pressure regulation is associated with the severity of essential hypertension and has been reported in hypertension due to renal disease. We therefore looked for a possible link between microalbuminuria and the smaller decrease in nocturnal blood pressure that occurs in essential hypertension.METHODS: The 24 h ambulatory blood pressure of 52 subjects with essential hypertension was measured and their urine tested for microalbuminuria (urinary albumin excretion of 30-300 mg/24 h). RESULTS: The subjects with (n = 10) and without (n = 42) microalbuminuria were comparable in clinical characteristics, antihypertensive treatments and serum creatinine. They had significantly different night-time systolic, diastolic and mean blood pressure decreases on ambulatory blood pressure monitoring. Two-factor analysis of variance showed that the day-night blood pressure decrease was linked to microalbuminuria status. The day-night blood pressure change of subjects with microalbuminuria differed from that of subjects without microalbuminuria independently from the daytime blood pressure level. CONCLUSION: Subjects with essential hypertension and microalbuminuria show a loss of nocturnal blood pressure decline. Whether microalbuminuria indicates a subtype of essential hypertension due to renal disease or severe hypertension with early renal damage remains to be clarified.     

Inverse relationship between ambulatory arterial stiffness index and glomerular filtration rate in arterial hypertension

BACKGROUND: Arterial stiffness and mild-to-moderate renal dysfunction are predictors of cardiovascular (CV) morbidity and mortality. Recently, the ambulatory arterial stiffness index (AASI) has been proposed as a surrogate index of arterial stiffness. It has been associated with an enhanced risk of stroke. The aim of our study was to assess the relationship between AASI and glomerular filtration rate (GFR) in a group of hypertensive patients with no CV complications. METHODS: A total of 143 untreated hypertensive subjects (mean age: 44 +/- 12 years; men 57%), with serum creatinine <1.5 mg/dl, were enrolled. AASI was calculated as one minus the regression slope of diastolic on systolic blood pressure (BP) obtained by individual 24-h BP recordings. GFR was computed from the scintigraphic determination of the technetium-99m diethylenetriaminepentaacetic acid uptake within the kidneys, by the Gates' method. RESULTS: Hypertensive patients with AASI above the median value (n = 71) had lower GFR than those with AASI below the median (n = 72) (98.3 +/- 31 vs. 122.4 +/- 32 ml/min/1.73 m(2); P < 0.001). This difference held even after adjustment for age and gender. The linear regression analysis disclosed a significant inverse correlation between GFR and AASI (r = -0.30; P < 0.001), that was replicated (beta = -0.19; P = 0.02) in a multiple regression model including, as independent variables (besides AASI), age, gender, high-density lipoprotein cholesterol, body mass index, 24-h pulse pressure (PP) and nocturnal reduction in BP. CONCLUSIONS: AASI is inversely related to GFR in arterial hypertension. This may help to explain the increased CV risk associated with mild-to-moderate renal dysfunction.     

Metabolic syndrome and ambulatory arterial stiffness index in non-diabetic patients with primary hypertension

Increased arterial stiffness and the presence of metabolic syndrome (MS) have been shown to predict cardiovascular events in patients with primary hypertension. We investigated the relationship between a recently proposed index of arterial stiffness derived from ambulatory blood pressure (BP) monitoring and MS in 156 untreated, non-diabetic patients with primary hypertension. Ambulatory arterial stiffness index (AASI) was defined as 1 minus the regression slope of diastolic over systolic BP readings obtained from 24-h recordings. A modified National Cholesterol Education Program definition for MS was used, with body mass index replacing waist circumference. The prevalence of MS was 23%. Patients with MS were more frequently male (0.0291) and had increased serum uric acid (P=0.0005), high-sensitivity C-reactive protein (P=0.0259), as well as total and low-density lipoprotein (LDL)-cholesterol (P=0.0374 and P=0.0350, respectively) as compared to those without MS. After adjusting for these confounders, the association between AASI and the presence of MS was statistically significant (P=0.0257). Moreover, the prevalence of increased AASI (upper tertile, that is >or=0.550) was greater in patients with MS (P=0.0156). After adjusting for age and 24-h mean BP, the presence of MS entailed a more than twofold greater risk for increased AASI (0.0280). MS is associated with increased AASI in non-diabetic patients with primary hypertension. These data support the role of this new index of arterial stiffness as a marker of risk and help to explain the high cardiovascular morbidity and mortality that is observed in hypertensive patients with MS.     

Comparison of renal resistive index among patients with Type 2 diabetes with different levels of creatinine clearance and urinary albumin excretion

Diabet. Med. 29, 1043–1046 (2012) Aim To evaluate the prevalence of increased renal resistive index and related factors among patients with Type 2 diabetes with different levels of creatinine clearance and urinary albumin excretion. Methods Laboratory analyses, including calculation of 24‐h urinary albumin excretion and 24‐h creatinine clearance, and renal doppler ultrasonography to measure renal resistive index, were carried out for patients newly diagnosed with Type 2 diabetes mellitus. Results Participants were classified into four groups according to 24‐h creatinine clearance and 24‐h urinary albumin excretion levels. Group 1 was composed of 73 patients (54.1%) with normal 24‐h creatinine clearance and 24‐h urinary albumin excretion. Group 2 was composed of 34 (25.2%) patients with normal 24‐h creatinine clearance and increased 24‐h urinary albumin excretion. Group 3 was composed of 14 (10.4%) patients with decreased 24‐h creatinine clearance and normal 24‐h urinary albumin excretion. Group 4 was composed of 14 (10.4%) patients with both decreased 24‐h creatinine clearance and increased 24‐h urinary albumin excretion . In total, 41 patients (30.4%) had increased renal resistive index levels. Comparison of the four groups with respect to increased renal resistive index revealed: among group 1 patients, 10 (13.7%) had increased renal resistive index levels; among group 2 patients, 14 (41.2%) had increased renal resistive index levels; among group 3 patients, eight (57.1%) had increased renal resistive index levels; among group 4 patients, nine (64.3%) had increased renal resistive index levels (P < 0.0001 for trend). In multivariate regression, 24‐h creatinine clearance (P < 0.0001), but not 24‐h urinary albumin excretion, was related to increased renal resistive index levels. Conclusion Renal resistive index levels were highest in patients with Type 2 diabetes with both decreased 24‐h creatinine clearance and increased 24‐h urinary albumin excretion, whereas they were lowest in patients with normal creatinine clearance and normal urinary albumin excretion.     

Ambulatory arterial stiffness index or pulse pressure: which correlates better with arterial stiffness in resistant hypertension?

The ambulatory arterial stiffness index (AASI) is a recently proposed index derived from 24-h ambulatory blood pressure monitoring (ABPM) for the evaluation of arterial stiffness. In this cross-sectional study we investigated whether AASI reflects arterial stiffness in patients with resistant hypertension by comparing AASI and ambulatory pulse pressure (PP) with aortic pulse wave velocity (PWV), a measure of arterial stiffness, in 391 resistant hypertensives. Clinical, laboratory and echocardiographic variables, 24-h ABPM and aortic PWV (measured using the Complior device) were obtained. AASI was calculated as 1--the regression slope of 24-h diastolic on systolic blood pressure (BP). Statistical analysis involved single and multiple linear regressions to assess the correlations between the two ABPM variables and PWV, both unadjusted and adjusted for potential confounders (age, gender, body height, presence of diabetes, 24-h mean arterial pressure [MAP], heart rate, and nocturnal BP reduction). Ambulatory PP and aortic PWV were independently associated with age, gender, presence of diabetes, and 24-h MAP, whereas AASI was associated with age, diabetes, and nocturnal diastolic BP reduction. PP showed stronger unadjusted (r=0.39, p<0.001) and adjusted (r=0.22, p<0.001) correlations with aortic PWV than AASI (r=0.12, p=0.032 and r= -0.04, p=0.47, respectively). In the analysis of subgroups stratified by gender, age, presence of atherosclerotic diseases and diabetes, dipping pattern, and ambulatory BP control, the superiority of PP over AASI was apparent in all subgroups. In conclusion, 24-h ambulatory PP was better correlated to arterial stiffness, as evaluated by aortic PWV, than the novel AASI, in patients with resistant hypertension.     

Mild renal dysfunction and subclinical cardiovascular damage in primary hypertension

The presence of mild renal dysfunction is associated with high cardiovascular morbidity and mortality rates in patients with primary hypertension. The pathophysiological mechanisms underlying this association are currently unknown. We investigated the relation between mild renal dysfunction and subclinical cardiovascular organ damage in 358 never previously treated patients with primary hypertension. Mild renal dysfunction was defined as a creatinine clearance <60 mL/min and/or the presence of microalbuminuria. Left ventricular mass index and carotid intima-media thickness were assessed by ultrasound scan. The prevalence of mild renal dysfunction, left ventricular hypertrophy, and carotid plaque was 18%, 48%, and 28%, respectively. Mild renal dysfunction was related to the presence of several risk factors, such as older age, higher blood pressure levels and lipid status, and smoking habits. Patients with the highest left ventricular mass and carotid intima-media thickness (upper quartiles) showed a higher prevalence of mild renal dysfunction (P<0.0001). After adjusting for duration of hypertension, mean blood pressure, smoking habits, and age, we found that the risk of left ventricular hypertrophy and/or carotid atherosclerosis increased by 43% with each SD reduction in creatinine clearance, and by 89% with each SD increase in albuminuria. Mild renal dysfunction is associated with preclinical end-organ damage in patients with primary hypertension. These data may help explain the high cardiovascular mortality rates reported in patients with low glomerular filtration rate or with increased albuminuria. The evaluation of creatinine clearance and urinary albumin excretion could be useful for identifying subjects at higher cardiovascular risk.     

Microalbuminuria, blood pressure load, and systemic vascular permeability in primary hypertension

BACKGROUND: Microalbuminuria, a powerful predictor of cardiovascular events, is thought to reflect widespread subclinical vascular abnormalities. To explore the pathogenesis of increased urinary albumin excretion in primary hypertension we evaluated systemic capillary permeability and ambulatory blood pressure (BP) measurement in two groups of matched untreated patients with (n = 11) and without (n = 29) microalbuminuria. METHODS: Albuminuria was measured as the mean of albumin-to-creatinine ratio (ACR) in three nonconsecutive first morning urine samples. Systemic capillary permeability was evaluated by transcapillary escape rate of albumin (TERalb) (ie, the 1-h decline rate of intravenous (125)I-albumin). Twenty-four-hour ambulatory BP, renal hemodynamics, and hormones of the renin-angiotensin-aldosterone system (RAAS) were also assessed. RESULTS: Patients with microalbuminuria showed greater body mass index (BMI) (P < .04), higher 24-h systolic and diastolic BP levels (P = .02), and higher capillary permeability to albumin (P < .02) as compared to normoalbuminurics. Renal hemodynamics and RAAS hormones were similar in the two groups. Univariate analysis showed that urinary ACR was related to ambulatory pressure components (P < .02), TERalb (r = 0.31, P < .05), smoking habits (r = 0.36, P = .02), and left ventricular mass index (LVMI) (r = 0.57, P < .001) among the whole study group. Logistic regression analysis showed that each 1% increment in TERalb or 10 mm Hg increase in systolic BP entailed an almost three times higher risk of having microalbuminuria. CONCLUSIONS: Microalbuminuria is associated with greater systemic BP load and increased vascular permeability in patients with primary hypertension.     

Urinary albumin excretion is associated with nocturnal systolic blood pressure in resistant hypertensives

Microalbuminuria is a known marker of subclinical organ damage. Its prevalence is higher in patients with resistant hypertension than in subjects with blood pressure at goal. On the other hand, some patients with apparently well-controlled hypertension still have microalbuminuria. The current study aimed to determine the relationship between microalbuminuria and both office and 24-hour ambulatory blood pressure. A cohort of 356 patients (mean age 64 ± 11 years; 40.2% females) with resistant hypertension (blood pressure ≥ 140 and/or 90 mm Hg despite treatment with ≥ 3 drugs, diuretic included) were selected from Spanish hypertension units. Patients with estimated glomerular filtration rate <30 mL/min/1.73 m(2) were excluded. All patients underwent clinical and demographic evaluation, complete laboratory analyses, and good technical-quality 24-hour ambulatory blood pressure monitoring. Urinary albumin/creatinine ratio was averaged from 3 first-morning void urine samples. Microalbuminuria (urinary albumin/creatinine ratio ≥ 2.5 mg/mmol in males or ≥ 3.5 mg/mmol in females) was detected in 46.6%, and impaired renal function (estimated glomerular filtration rate <60 mL/min/1.73 m(2)) was detected in 26.8%. Bivariate analyses showed significant associations of microalbuminuria with older age, reduced estimated glomerular filtration rate, increased nighttime systolic blood pressure, and elevated daytime, nighttime, and 24-hour diastolic blood pressure. In a logistic regression analysis, after age and sex adjustment, elevated nighttime systolic blood pressure (multivariate odds ratio, 1.014 [95% CI, 1.001 to 1.026]; P=0.029) and reduced estimated glomerular filtration rate (multivariate odds ratio, 2.79 [95% CI, 1.57 to 4.96]; P=0.0005) were independently associated with the presence of microalbuminuria. We conclude that microalbuminuria is better associated with increased nighttime systolic blood pressure than with any other office and 24-hour ambulatory blood pressure monitoring parameters.     

Valsartan Reduces Serum Cystatin C and the Renal Vascular Resistance in Patients with Essential Hypertension

A high level of albuminuria and increased renal vascular resistance are associated with hypertensive renal damage. In this study, the authors investigated the effect of the angiotensin II receptor blocker, valsartan, on renal function and intrarenal hemodynamics in non-diabetic patients with essential hypertension. A prospective three-month study of the effects of valsartan, 40–80 mg/day, was performed in 30 hypertensive patients. As an assessment of renal function, serum creatinine, urine albumin/creatinine (Alb/Cr) ratio, and serum cystatin C levels were evaluated. Doppler ultrasonography of the kidney was performed for the evaluation of renal hemodynamics. Peak-systolic, end-diastolic, and mean velocities of interlobar arteries were evaluated, and the pulsatility index (PI) and resistive index (RI) were calculated. It was determined that patients with microalbuminuria had higher levels of serum cystatin C, PI, and RI compared to patients without microalbuminuria. Valsartan treatment significantly reduced systolic and diastolic blood pressure and decreased the Alb/Cr ratio. Serum creatinine was not changed, whereas serum cystatin C levels were significantly reduced. Valsartan treatment significantly decreased the PI in all patients and both PI and RI in patients with microalbuminuria. These results suggest that the angiotensin II receptor blocker, valsartan, is able to improve renal function by reducing renal vascular resistance in hypertensive patients, especially in patients with microalbuminuria, and may prevent future renal failure in patients with essential hypertension.     

Valsartan reduces serum cystatin C and the renal vascular resistance in patients with essential hypertension

A high level of albuminuria and increased renal vascular resistance are associated with hypertensive renal damage. In this study, the authors investigated the effect of the angiotensin II receptor blocker, valsartan, on renal function and intrarenal hemodynamics in non-diabetic patients with essential hypertension. A prospective three-month study of the effects of valsartan, 40-80 mg/day, was performed in 30 hypertensive patients. As an assessment of renal function, serum creatinine, urine albumin/creatinine (Alb/Cr) ratio, and serum cystatin C levels were evaluated. Doppler ultrasonography of the kidney was performed for the evaluation of renal hemodynamics. Peak-systolic, end-diastolic, and mean velocities of interlobar arteries were evaluated, and the pulsatility index (PI) and resistive index (RI) were calculated. It was determined that patients with microalbuminuria had higher levels of serum cystatin C, PI, and RI compared to patients without microalbuminuria. Valsartan treatment significantly reduced systolic and diastolic blood pressure and decreased the Alb/Cr ratio. Serum creatinine was not changed, whereas serum cystatin C levels were significantly reduced. Valsartan treatment significantly decreased the PI in all patients and both PI and RI in patients with microalbuminuria. These results suggest that the angiotensin II receptor blocker, valsartan, is able to improve renal function by reducing renal vascular resistance in hypertensive patients, especially in patients with microalbuminuria, and may prevent future renal failure in patients with essential hypertension.     

Left ventricular mass assessed by electrocardiography and albumin excretion rate as a continuum in untreated essential hypertension

OBJECTIVE: To study an association between albumin excretion rate and left ventricular mass (LVM) determined by electrocardiogram (ECG)-based criteria, and with respect to ambulatory blood pressure, in patients with newly diagnosed and never-treated essential hypertension. METHODS: We measured 24 h ambulatory blood pressure, albumin excretion rate and LVM in 74 patients with newly diagnosed (within the past year) and never-treated essential hypertension, who were admitted to the hypertension clinic (Ulleval University Hospital). Albumin excretion rate was evaluated by determination of the albumin:creatinine ratio in the first-voided morning urine sample. LVM was assessed by ECG using Cornell voltage-QRS duration product and Sokolow- Lyon criteria. RESULTS: Albumin excretion rate was significantly related to ambulatory blood pressure. There was a weak but significant negative correlation between the decrease in diastolic blood pressure during the night and the rate of excretion of albumin. The patients classified as dippers had a significantly lower albumin excretion rate compared with the non-dippers (1.36+/-0.83 compared with 1.68+/-0.87 mg/mmol; P = 0.03). LVM was found to be significantly related to ambulatory blood pressure. A weak relationship was observed between albumin excretion rate and LVM as evaluated by Cornell criterion (r = 0.23, P = 0.045). When only normoalbuminuric patients were included (i.e. four patients with microalbuminuria were excluded), the relationship was stronger (r = 0.36, P = 0.002). CONCLUSIONS: The present findings show a continuous relationship between albumin excretion rate, LVM and ambulatory blood pressure in newly diagnosed patients with essential hypertension, and suggest the occurrence of early effects on target organs (kidneys and heart). These associations were observed using easily applicable methods such as ECG monitoring and determination of the albumin:creatinine ratio in morning urine samples.     

Renal hemodynamics and renal function after catheter-based renal sympathetic denervation in patients with resistant hypertension

Increased renal resistive index and urinary albumin excretion are markers of hypertensive end-organ damage and renal vasoconstriction involving increased sympathetic activity. Catheter-based sympathetic renal denervation (RD) offers a new approach to reduce renal sympathetic activity and blood pressure in resistant hypertension. The influence of RD on renal hemodynamics, renal function, and urinary albumin excretion has not been studied. One hundred consecutive patients with resistant hypertension were included in the study; 88 underwent interventional RD and 12 served as controls. Systolic, diastolic, and pulse pressure, as well renal resistive index in interlobar arteries, renal function, and urinary albumin excretion, were measured before and at 3 and 6 months of follow-up. RD reduced systolic, diastolic, and pulse pressure at 3 and 6 months by 22.7/26.6 mm Hg, 7.7/9.7 mm Hg, and 15.1/17.5 mm Hg (P for all <0.001), respectively, without significant changes in the control group. SBP reduction after 6 months correlated with SBP baseline values (r=-0.46; P<0.001). There were no renal artery stenoses, dissections, or aneurysms during 6 months of follow-up. Renal resistive index decreased from 0.691±0.01 at baseline to 0.674±0.01 and 0.670±0.01 (P=0.037/0.017) at 3- and 6-month follow-up. Mean cystatin C glomerular filtration rate and urinary albumin excretion remained unchanged after RD; however, the number of patients with microalbuminuria or macroalbuminuria decreased. RD reduced blood pressure, renal resistive index, and incidence of albuminuria without adversely affecting glomerular filtration rate or renal artery structure within 6 months and appears to be a safe and effective therapeutic approach to lower blood pressure in patients with resistant hypertension.