Mai Yanagi

Effect of losartan on ambulatory short-term blood pressure variability and cardiovascular remodeling in hypertensive patients on hemodialysis

OBJECTIVE Previous studies have shown increases in ambulatory short-term blood pressure (BP) variability to be related to cardiovascular disease. In this study, we examined whether an angiotensin II type 1 receptor blocker losartan would improve ambulatory short-term BP variability in hypertensive patients on hemodialysis. METHODS Forty hypertensive patients on hemodialysis therapy were randomly assigned to the losartan treatment group (n=20) or the control treatment group (n=20). At baseline and 6 and 12 months after the treatment, 24-h ambulatory BP monitoring was performed. Echocardiography and measurements of brachial-ankle pulse wave velocity (baPWV) and biochemical parameters were also performed before and after therapy. RESULTS After 6- and 12-months of treatment, nighttime short-term BP variability, assessed on the basis of the coefficient of variation of ambulatory BP, was significantly decreased in the losartan group, but remained unchanged in the control group. Compared with the control group, losartan significantly decreased left ventricular mass index (LVMI), baPWV, and the plasma levels of brain natriuretic peptide and advanced glycation end products (AGE). Furthermore, multiple regression analysis showed significant correlations between changes in LVMI and changes in nighttime short-term BP variability, as well as between changes in LVMI and changes in the plasma levels of AGE. CONCLUSION These results suggest that losartan is beneficial for the suppression of pathological cardiovascular remodeling though its inhibitory effect on ambulatory short-term BP variability during nighttime.

Effects of angiotensin II type 1 receptor blocker on ambulatory blood pressure variability in hypertensive patients with overt diabetic nephropathy.

Previous studies have shown increases in ambulatory short-term blood pressure (BP) variability to be related to cardiovascular disease. In this study, we examined whether the angiotensin II type 1 receptor blocker (ARB) would improve ambulatory short-term BP variability in hypertensive patients with diabetic nephropathy. A total of 30 patients with type II diabetes, along with hypertension and overt nephropathy, were enrolled in this randomized, two-period, crossover trial of 12 weeks of treatment with losartan (50 mg daily) and telmisartan (40 mg daily). At baseline and at the end of each treatment period, 24-h ambulatory BP monitoring with power spectral analysis of heart rate and measurements of proteinuria, estimated glomerular filtration rate and brachial-ankle pulse wave velocity (baPWV) were performed. After 12 weeks of treatment, 24-h, daytime and nighttime short-term BP variability, assessed on the basis of the coefficient of variation of ambulatory BP, was significantly decreased by telmisartan. Both losartan and telmisartan reduced urinary protein excretion and baPWV. However, compared with losartan, telmisartan significantly decreased urinary protein excretion, baPWV and low-frequency (LF)-to-high-frequency (HF) ratio, an index of sympathovagal balance. Multiple regression analysis showed significant correlations between urinary protein excretion and baPWV, 24-h LF-to-HF ratio, nighttime systolic BP and 24-h short-term systolic BP variability. These results suggest that ARB, particularly telmisartan, is effective in reducing proteinuria in hypertensive patients with overt diabetic nephropathy, partly through inhibitory effects on ambulatory short-term BP variability and sympathetic nerve activity, in addition to its longer duration of action on nighttime BP reduction.

Identification of an increased short-term blood pressure variability on ambulatory blood pressure monitoring as a coronary risk factor in diabetic hypertensives.

We examined risk factors for coronary heart disease (CHD) by ambulatory blood pressure (BP) monitoring in 72 diabetic hypertensives who were hospitalized for the educational program. The patients were divided into two groups (CHD group, 19 subjects; and non-CHD group, 53 subjects) along with or without co-existing CHD. On ambulatory BP monitoring, no significant differences were found between the groups regarding BP values through the day. However, the CHD group had a significantly grater BP variability than non-CHD group. The result of logistic regression analysis demonstrated that nighttime systolic BP variability was an independent risk factor for CHD.

Expression of angiotensin II type 1 receptor-interacting molecule in normal human kidney and IgA nephropathy

The intrarenal renin-angiotensin system plays a crucial role in the regulation of renal circulation and sodium reabsorption through the activation of vascular, glomerular, and tubular angiotensin II type 1 (AT(1)) receptor signaling. We previously cloned a molecule that specifically interacted with the murine AT(1) receptor to inhibit AT(1) receptor signaling, which we named ATRAP (for AT(1) receptor-associated protein). Since murine ATRAP was shown to be highly expressed in the kidney, in the present study we investigated expression and distribution of human ATRAP in normal kidney and renal biopsy specimens from patients with IgA nephropathy. In the normal human kidney, both ATRAP mRNA and protein were widely and abundantly distributed along the renal tubules from Bowmans capsule to the medullary collecting ducts. In all renal tubular epithelial cells, the ATRAP protein colocalized with the AT(1) receptor. In renal biopsy specimens with IgA nephropathy, a significant positive correlation between ATRAP and AT(1) receptor gene expression was observed. There was also a positive relationship between tubulointerstitial ATRAP expression and the estimated glomerular filtration rate in patients with IgA nephropathy. Furthermore, we examined the function of the tubular AT(1) receptor using an immortalized cell line of mouse distal convoluted tubule cells (mDCT) and found that overexpression of ATRAP by adenoviral gene transfer suppressed the angiotensin II-mediated increases in transforming growth factor-β production in mDCT cells. These findings suggest that ATRAP might play a role in balancing the renal renin-angiotensin system synergistically with the AT(1) receptor by counterregulatory effects in IgA nephropathy and propose an antagonistic effect of tubular ATRAP on AT(1) receptor signaling.

Effects of aliskiren-based therapy on ambulatory blood pressure profile, central hemodynamics, and arterial stiffness in nondiabetic mild to moderate hypertensive patients.

J Clin Hypertens (Greenwich). 2012;00:000–000. ©2012 Wiley Periodicals, Inc.

The angiotensin II type 1 receptor blocker olmesartan preferentially improves nocturnal hypertension and proteinuria in chronic kidney disease

Accumulated evidence suggests that an altered ambulatory blood pressure (BP) profile, particularly elevated nighttime BP, reflects target organ injury and is a better predictor of further cardiorenal risk than the clinic BP or daytime BP in hypertensive patients complicated by chronic kidney disease (CKD). In this study, we examined the beneficial effects of olmesartan, an angiotensin II type 1 receptor blocker (ARB), on ambulatory BP profiles and renal function in hypertensive CKD patients. Forty-six patients were randomly assigned to the olmesartan add-on group (n=23) or the non-ARB group (n=23). At baseline and after the 16-week treatment period, ambulatory BP monitoring was performed and renal function parameter measurements were collected. Although the baseline clinic BP levels and the after-treatment/baseline (A/B) ratios of clinic BP levels were similar in the olmesartan add-on and non-ARB groups, the A/B ratios of ambulatory 24-h and nighttime BP levels in the olmesartan add-on group were significantly lower. Furthermore, the A/B ratios of urinary protein, albumin and type IV collagen excretion in the olmesartan add-on group were significantly lower than those in the non-ARB group (urinary protein excretion, 0.72±0.41 vs. 1.45±1.48, P=0.030; urinary albumin excretion, 0.73±0.37 vs. 1.50±1.37, P=0.005; urinary type IV collagen excretion, 0.87±0.42 vs. 1.48±0.87, P=0.014) despite comparable A/B ratios for the estimated glomerular filtration rate in the two groups. These results indicate that in hypertensive patients with CKD, olmesartan add-on therapy improves the ambulatory BP profile via a preferential reduction in nighttime BP with concomitant renal injury inhibition.

Effects of Multiple Factorial Intervention on Ambulatory BP Profile and Renal Function in Hypertensive Type 2 Diabetic Patients with Overt Nephropathy – A Pilot Study

Abstract Accumulating evidence has shown that diabetic patients are increasing in number, and renal and cardiovascular complications are the most common cause of death in diabetic patients. Thus, it would be of considerable value to identify the mechanisms involved in the progression of renal impairment and cardiovascular injury associated with diabetes. Recent evidence also indicated that multifactorial intervention is able to reduce the risk of cardiovascular disease and death among patients with diabetes and microalbuninuria. In this pilot study, we examined the effects of intensified multifactorial intervention, with tight glucose regulation and the use of valsartan and fluvastatin on ambulatory blood pressure (BP) profile, estimated glomerular filtration rate (eGFR), and urinary albumin to creatinine ratio (UACR), in 20 hypertensive patients (16 male and 4 female) with type 2 diabetes mellitus and overt nephropathy. After 12 months of intensified treatment, office BP, fasting plasma glucose (FPG), and low-density lipoprotein cholesterol (LDLC) were significantly decreased compared to baseline (systolic blood pressure (SBP), 130 ± 2 vs. 150 ± 1 mmHg; diastolic blood pressure (DBP), 76 ± 1 vs. 86 ± 1 mmHg; FPG, 117 ± 5 vs. 153 ± 7 mg/dl; LDLC, 116 ± 8 vs. 162 ± 5 mg/dl, P < 0.0001). Also, compared to the baseline values, the daytime and nighttime ambulatory BP and short-term BP variability were significantly decreased after 12 months. Furthermore, while eGFR was not altered (44.3 ± 5.1 vs. 44.3 ± 6.5 ml/min/1.73 m2, not significant (NS)), UACR showed a significant reduction after 12 months of intensified treatment (1228 ± 355 vs. 2340 ± 381 mg/g-cr, P < 0.05). These results suggest that the intensified multifactorial intervention is able to improve ambulatory BP profile, preserve renal function, and reduce urinary albumin excretion in type 2 diabetic hypertensive patients with overt nephropathy.

Relationship of Ambulatory Blood Pressure and the Heart Rate Profile with Renal Function Parameters in Hypertensive Patients with Chronic Kidney Disease

Strict blood pressure (BP) control is reportedly important for the management of hypertensive patients with chronic kidney disease (CKD). The purpose of this cross-sectional study was to examine whether the variables of ambulatory BP and the heart rate (HR) profile, central hemodynamics, and arterial stiffness were closely related to the renal function parameters (urine albumin excretion rate [UACR] and estimated glomerular filtration rate [eGFR]) observed in 25 consecutive hospitalized hypertensive patients with CKD. There were significant positive relationships between UACR and 24-hour, daytime, and nighttime ambulatory systolic BP. In addition, there were significant negative relationships between UACR and 24-hour and daytime HR variability. The circulating B-type natriuretic peptide level and hemoglobin A1c were also positively related to UACR. With respect to eGFR, although the 24-hour and nighttime HR variability were positively associated with eGFR, the circulating pentosidine and nighttime HR had a negative relationship with eGFR. On the other hand, central hemodynamics and arterial stiffness did not exhibit any significant association with renal function parameters. These results indicate that ambulatory BP and the HR profile are closely modulated by renal function deterioration. Further studies are needed to investigate the causal relationship between ambulatory BP and the HR profile and renal function parameters in hypertensive patients with CKD.

L/N-type calcium channel blocker cilnidipine added to renin-angiotensin inhibition improves ambulatory blood pressure profile and suppresses cardiac hypertrophy in hypertension with chronic kidney disease.

Ambulatory blood pressure (BP) and heart rate (HR) profile are proposed to be related to renal deterioration and cardiovascular complication in hypertension and chronic kidney disease (CKD). In this study, we examined the beneficial effects cilnidipine, a unique L/N-type calcium channel blocker (CCB), in addition to renin-angiotensin system inhibitors, on ambulatory BP and HR profile, as well as cardiorenal function in hypertensive CKD patients. Forty-five patients were randomly assigned to the cilnidipine replacement group (n = 21) or the control CCBs group (n = 24) during a 24-week active treatment period. Although clinical BP values were similar in the cilnidipine and control CCBs groups after the treatment period, the results of ambulatory BP monitoring showed that the 24-h and daytime systolic BP levels in the cilnidipine group were significantly lower compared with the control group after the study. Furthermore, the left ventricular mass index (LVMI) was significantly decreased in the cilnidipine group compared to the control group after the study (LVMI, 135.3 ± 26.4 versus 181.2 ± 88.4, p = 0.031), with a significant difference in the changes in the LVMI between the cilnidipine and control groups (change in LVMI, −12.4 ± 23.7 versus 26.2 ± 64.4, p = 0.007). These results indicate that cilnidipine is beneficial for the suppression of pathological cardiac remodeling, at least partly, via a superior improving effect on ambulatory BP profile compared with control CCBs in hypertensive CKD patients.

Combination Therapy of Angiotensin II Receptor Blocker and Calcium Channel Blocker Exerts Pleiotropic Therapeutic Effects in Addition to Blood Pressure Lowering: Amlodipine and Candesartan Trial in Yokohama (ACTY)

Recent guidelines recommend combination antihypertensive therapy to achieve the target blood pressure (BP) and to suppress target organ damage. This study aimed to examine the beneficial effects of combination therapy with candesartan and amlodipine on BP control and markers of target organ function in Japanese essential hypertensive patients (N = 20) who did not achieve the target BP level during the monotherapy period with either candesartan or amlodipine. After the monotherapy period, for patients already being treated with amlodipine, a once-daily 8 mg dose of candesartan was added on during the combination therapy period (angiotensin II receptor blocker [ARB] add-on group, N = 10), and a once-daily 5 mg dose of amlodipine was added on for those already being treated with candesartan (calcium channel blocker [CCB] add-on group, N = 10). Combination therapy with candesartan and amlodipine for 12 weeks significantly decreased clinic and home systolic blood pressure (SBP) and diastolic blood pressure (DBP). In addition, the combination therapy was able to significantly reduce urine albumin excretion without decrease in estimated glomerular filtration ratio and resulted in significant improvements in brachial-ankle pulse wave velocity, central SBP, and insulin sensitivity. Furthermore, the CCB add-on group showed a significantly greater decrease in clinic and home DBP than the ARB add-on group. The calcium channel blocker add-on group also exhibited better improvements in vascular functional parameters than the ARB add-on group. These results suggest that combination therapy with candesartan and amlodipine is an efficient therapeutic strategy for hypertension with pleiotropic benefits.