Combination therapy with renin-angiotensin system inhibitors and the calcium channel blocker azelnidipine decreases plasma inflammatory markers and urinary oxidative stress markers in patients with diabetic nephropathy

Azelnidipine and its role in decreasing urinary albumin creatinine ratio in people with type 2 diabetes and hypertension: a systematic review and meta-analysis

Purpose

Type 2 diabetes mellitus and hypertension frequently coexist, increasing the risk of cardiovascular and renal complications. Urinary Albumin Creatinine Ratio (UACR) serves as a crucial predictor of these outcomes. While renin-angiotensin system inhibitors are often initial therapy, evidence suggests a potential role for Azelnidipine, a non-dihydropyridine calcium channel blocker, in reducing UACR, especially in cases of persistent proteinuria despite optimal therapy. However, conflicting results from existing studies necessitate a comprehensive systematic review and meta-analysis to clarify Azelnidipine's (AZL) efficacy in reducing UACR in people with type 2 diabetes mellitus and hypertension.

Methods

This meta-analysis, following Cochrane and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, included randomized controlled trials (RCTs) published until January 15, 2024. Studies involving individuals with type 2 diabetes mellitus and hypertension were included, comparing AZL or AZL-containing regimens with other antihypertensive agents. The primary outcome was changes in UACR, with secondary outcomes including alterations in Glycated Hemoglobin (HbA1c), systolic and diastolic blood pressure (SBP and DBP), heart rate (HR), and estimated glomerular filtration rate (eGFR).

Results

Six RCTs involving 731 participants were included. Meta-analysis revealed a significant reduction in UACR in the AZL group compared to controls (Mean Difference (MD) = -47.96; 95% Confidence Interval (CI): -79.56, -16.37; p = 0.003). AZL also significantly decreased HR (MD = -3.70; 95% CI: -6.66, -0.74; p = 0.01), while no significant changes were observed in HbA1c, SBP, DBP, or eGFR. Sensitivity analyses demonstrated the nuanced impacts of individual studies on results, highlighting the importance of careful interpretation.

Conclusion

This meta-analysis confirms AZL's efficacy in reducing UACR and HR in people with type 2 diabetes mellitus and hypertension.

N-/T-Type vs. L-Type Calcium Channel Blocker in Treating Chronic Kidney Disease: A Systematic Review and Meta-Analysis

Renin-angiotensin system (RAS) inhibitors and calcium channel blockers (CCB) are often used together in chronic kidney disease (CKD). The PubMed, EMBASE, and Cochrane Library databases were searched to identify randomized controlled trials (RCTs) in order to explore better subtypes of CCB for the treatment of CKD. This meta-analysis of 12 RCTs with 967 CKD patients who were treated with RAS inhibitors demonstrated that, when compared with L-type CCB, N-/T-type CCB was superior in reducing urine albumin/protein excretion (SMD, −0.41; 95% CI, −0.64 to −0.18; p < 0.001) and aldosterone, without influencing serum creatinine (WMD, −3.64; 95% CI, −11.63 to 4.35; p = 0.37), glomerular filtration rate (SMD, 0.06; 95% CI, −0.13 to 0.25; p = 0.53), and adverse effects (RR, 0.95; 95% CI, 0.35 to 2.58; p = 0.93). In addition, N-/T-type CCB did not decrease the systolic blood pressure (BP) (WMD, 0.17; 95% CI, −1.05 to 1.39; p = 0.79) or diastolic BP (WMD, 0.64; 95% CI, −0.55 to 1.83; p = 0.29) when compared with L-type CCB. In CKD patients treated with RAS inhibitors, N-/T-type CCB is more effective than L-type CCB in reducing urine albumin/protein excretion without increased serum creatinine, decreased glomerular filtration rate, and increased adverse effects. The additional benefit is independent of BP and may be associated with decreased aldosterone (PROSPERO, CRD42020197560).

Therapeutic Usefulness of a Novel Calcium Channel Blocker Azelnidipine in the Treatment of Hypertension: A Narrative Review

The prevalence of hypertension and comorbidities such as metabolic syndrome, diabetes mellitus, and chronic kidney disease in India is alarmingly high. Amlodipine, an older-generation calcium channel blocker (CCB), is currently the gold standard for hypertension management in India. However, it has several disadvantages, including reflex tachycardia and pedal edema. Therefore, an effective antihypertensive agent that does not cause these adverse effects and provides end-organ protection is required for the holistic management of hypertension in the country. Azelnidipine is a new-generation CCB that has recently been approved for the treatment of hypertension in India. This review provides an overview of the utility of azelnidipine for hypertension control, including comparisons with traditional CCBs such as amlodipine. It discusses the key antihypertensive effects of azelnidipine as well as its advantages in the prevention of tachycardia and associated complications. In addition, this review highlights the extensive cardio- and renoprotective activities of azelnidipine, including its effects on systolic and diastolic function and urinary albumin excretion. Overall, this substantial body of evidence supports the use of azelnidipine for the treatment of hypertension, especially in India. It suggests that the adoption of azelnidipine as the new gold standard CCB could help India battle its hypertension epidemic.

Potential protective effects of Azelnidipine against cerebral ischemia-reperfusion injury in male rats

This study was performed to evaluate the neuroprotective effect of Azelnidipine in cerebral ischemia/reperfusion and to envisage its mechanisms. Twenty-eight adult male Sprague-Dawley rats weighing 200-300 g were randomized into 4 groups (7 rats in each group). Sham (neck dissection without bilateral common carotid artery occlusion), control (30 minutes of bilateral common carotid artery occlusion and reperfusion for 1 hour), vehicle (identical volume of 0.3% carboxymethylcellulose (CMC) orally every day then bilateral common artery occlusion and reperfusion), and Azelnipine-treated rats (7 days of Azelnidipine pretreatment 3 mg/kg/day followed by bilateral common carotid artery occlusion and reperfusion). In addition to brain infarct volume and histopathological assessment, the brain tissues were harvested to evaluate cerebral IL-6, IL-10, TNF-α, ICAM-1, NF-κB p65, and total antioxidant capacity levels. Cerebral levels of IL-6, IL-10, TNF-α, NF-κB p65, and ICAM-1, besides cerebral infarct volume, were significantly elevated in control and vehicle related to sham groups, while total antioxidant capacity was markedly reduced. Azelnidipine treatment resulted in remarkable upregulation of total antioxidant capacity; meanwhile, IL-6, TNF-α, NF-κB p65, and ICAM-1 showed a considerable reduction. Cerebral IL-10 levels were not affected by Azelnidipine pretreatment. Histologically, control and vehicle rats showed severe ischemic injury, which was greatly reversed by Azelnidipine treatment. The current study disclosed that Azelnidipine could markedly reduce cerebral infarct volume and ameliorate histopathological damage in male rats exposed to cerebral ischemia/reperfusion. The neuroprotective effects of Azelnidipine probably stemmed from its anti-inflammatory and antioxidative properties. Azelnidipine had no effect on cerebral IL-10 levels.

An Indole-2-Carboxamide Derivative, LG4, Alleviates Diabetic Kidney Disease Through Inhibiting MAPK-Mediated Inflammatory Responses

Aim

Elevated inflammatory signaling has been shown to play an important role in diabetic kidney disease (DKD). We previously developed a new anti-inflammatory compound LG4. In the present study, we have tested the hypothesis that LG4 could prevent DKD by suppressing inflammation and identified the underlying mechanism.

Methods

Streptozotocin-induced type 1 diabetic mice were used to develop DKD and evaluate the effects of LG4 against DKD. To identify the potential targets of LG4, biotin-linked LG4 was synthesized and subjected to proteome microarray screening. The cellular mechanism of LG4 was investigated in HG-challenged SV40MES13 cells.

Results

Although LG4 treatment had no effect on the body weight and blood glucose levels, it remarkably reversed the hyperglycemia-induced pathological changes and fibrosis in the kidneys of T1DM mice. Importantly, hyperglycemia-induced renal inflammation evidenced by NF-κB activation and TNFα and IL-6 overexpression was greatly ameliorated with LG4 treatment. Proteosome microarray screening revealed that JNK and ERK were the direct binding proteins of LG4. LG4 significantly reduced HG-induced JNK and ERK phosphorylation and subsequent NF-κB activation in vivo and in vitro. In addition, LG4 did not show further anti-inflammatory effect in HG-challenged mesangial cells with the presence of JNK or ERK inhibitor.

Conclusion

LG4 showed renoprotective activity through inhibiting ERK/JNK-mediated inflammation in diabetic mice, indicating that LG4 may be a therapeutic agent for DKD.

Association of Serum PSP/REG Iα with Renal Function in Type 2 Diabetes Mellitus

PURPOSE

Pancreatic stone protein/regenerating protein I (PSP/REG Iα) is a secretory protein mainly detected in the pancreas. Recent studies revealed increased serum PSP/REG Iα) is a secretory protein mainly detected in the pancreas. Recent studies revealed increased serum PSP/REG Iα) is a secretory protein mainly detected in the pancreas. Recent studies revealed increased serum PSP/REG I.

METHODS

This cross-sectional study was conducted at Zhongda Hospital, affiliated with Southeast University in China. Serum PSP/REG Iα) is a secretory protein mainly detected in the pancreas. Recent studies revealed increased serum PSP/REG Iα) is a secretory protein mainly detected in the pancreas. Recent studies revealed increased serum PSP/REG I.

RESULTS

Serum PSP/REG Iα) is a secretory protein mainly detected in the pancreas. Recent studies revealed increased serum PSP/REG IP < 0.05). The level of PSP/REG Iα) is a secretory protein mainly detected in the pancreas. Recent studies revealed increased serum PSP/REG Iα) is a secretory protein mainly detected in the pancreas. Recent studies revealed increased serum PSP/REG I.

CONCLUSIONS

Serum PSP/REG Iα level is significantly upregulated in T2DM patients and reflects renal function in both T2DM and nondiabetic control groups. The relationship between PSP/REG Iα and eGFR suggested that PSP/REG Iα might be a potential indicator of renal dysfunction.α) is a secretory protein mainly detected in the pancreas. Recent studies revealed increased serum PSP/REG Iα) is a secretory protein mainly detected in the pancreas. Recent studies revealed increased serum PSP/REG Iα) is a secretory protein mainly detected in the pancreas. Recent studies revealed increased serum PSP/REG I.

Interventions targeted at oxidatively generated modifications of nucleic acids focused on urine and plasma markers

Oxidative stress is associated with the development and progression of numerous diseases. However, targeting oxidative stress has not been established in the clinical management of any disease. Several methods and markers are available to measure oxidative stress, including direct measurement of free radicals, antioxidants, redox balance, and oxidative modifications of cellular macromolecules. Oxidatively generated nucleic acid modifications have attracted much interest due to the pre-mutagenic oxidative modification of DNA into 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), associated with cancer development. During the last decade, the perception of RNA has changed from that of a 'silent messenger' to an 'active contributor', and, parallelly oxidatively generated RNA modifications measured as 8-oxo-7,8-dihydro-guanosine (8-oxoGuo), has been demonstrated as a prognostic factor for all-caused and cardiovascular related mortality in patients with type 2 diabetes. Several attempts have been made to modify the amount of oxidative nucleic acid modifications. Thus, this review aims to introduce researchers to the measurement of oxidatively generated nucleic acid modifications as well as critically review previous attempts and provide future directions for targeting oxidatively generated nucleic acid modifications.

Potential Protective Role of Blood Pressure-Lowering Drugs on the Balance between Hemostasis and Fibrinolysis in Hypertensive Patients at Rest and During Exercise

In patients with hypertension, the triad represented by endothelial dysfunction, platelet hyperactivity, and altered fibrinolytic function disturbs the equilibrium between hemostasis and fibrinolysis and translates into a hypercoagulable state, which underlies the risk of thrombotic complications. This article reviews the scientific evidence regarding some biological effects of antihypertensive drugs, which can protect patients from the adverse consequences of hypertensive disease, improving endothelial function, enhancing antioxidant activity, and restoring equilibrium between hemostatic and fibrinolytic factors. These protective effects appear not to be mediated through blood pressure reduction and are not shared by all molecules of the same pharmacological class.

Innate immune response in the pathogenesis of heart failure in survivors of myocardial infarction

Among the different cardiovascular disease complications, atherosclerosis-induced myocardial infarction (MI) is the major contributor of heart failure (HF) and loss of life. This review presents short- and long-term features of post-MI in human hearts and animal models. It is known that the heart does not regenerate, and thus loss of cardiac cells after an MI event is permanent. In survivors of a heart attack, multiple neurohumoral adjustments as well as simultaneous remodeling in both infarcted and noninfarcted regions of the heart help sustain pump function post-MI. In the early phase, migration of inflammatory cells to the infarcted area helps repair and remove the cell debris, while apoptosis results in the elimination of damaged cardiomyocytes, and there is an increase in the antioxidant response to protect the survived myocardium against oxidative stress (OS) injury. However, in the late phase, it appears that there is a relative increase in OS and activation of the innate inflammatory response in cardiomyocytes without any obvious inflammatory cells. In this late stage in survivors of MI, a progressive slow activation of these processes leads to apoptosis, fibrosis, cardiac dysfunction, and HF. Thus, this second phase of an increase in OS, innate inflammatory response, and apoptosis results in wall thinning, dilatation, and consequently HF. It is important to note that this inflammatory response appears to be innate to cardiomyocytes. Blunting of this innate immune cardiomyocyte response may offer new hope for the management of HF.

Schisandrin B alleviates diabetic nephropathy through suppressing excessive inflammation and oxidative stress

Diabetic nephropathy (DN) is a progressive kidney disease due to glomerular capillary damage in diabetic patients, with inflammation and oxidative stress implicated as crucial pathogenic factors. There is an urgent need to develop effective therapeutic drug. Natural medicines are rich resources for active lead compounds. They would provide new opportunities for the treatment of DN. The present study was designed to investigate the protective effects of Schisandrin B (SchB) on DN and to delineate the underlying mechanism. Oral administration of SchB in the diabetic mouse model significantly alleviated hyperglycemia-induced renal injury, which was accompanied by maintenance of urine creatinine and albumin levels at similar to those of control non-diabetic mice. Histological examination of renal tissue indicated that both development of fibrosis and renal cell apoptosis were dramatically inhibited by SchB. The protective effect of SchB on DN associated with suppression of inflammatory response and oxidative stress. These results strongly suggested that SchB could be a potential therapeutic agent for treatment of DN. Moreover, our findings provided a fuller understanding of the regulatory role of NF-κB and Nrf2 in DN, indicating that they could be important therapeutic targets.

Effect of Angiotensin-Converting Enzyme Inhibitor/Calcium Antagonist Combination Therapy on Renal Function in Hypertensive Patients With Chronic Kidney Disease: Chikushi Anti-Hypertension Trial - Benidipine and Perindopril

Background

Appropriate blood pressure control suppresses progression of chronic kidney disease (CKD). If an angiotensin-converting enzyme (ACE) inhibitor is ineffective, adding a calcium antagonist is recommended. We compared the long-term effect of two ACE inhibitor/calcium antagonist combinations on renal function in hypertensive patients with CKD.

Methods

Patients who failed to achieve the target blood pressure (systolic/diastolic: < 130/80 mm Hg) with perindopril monotherapy were randomized to either combined therapy with perindopril and the L-type calcium antagonist amlodipine (group A) or perindopril and the T/L type calcium antagonist benidipine (group B). The primary endpoint was the change of the estimated glomerular filtration rate (eGFR) after 2 years. Eligible patients had a systolic pressure ≥ 130 mm Hg and/or diastolic pressure ≥ 80 mm Hg and CKD (urine protein (+) or higher, eGFR < 60 min/mL/1.73 m²).

Results

After excluding 38 patients achieving the target blood pressure with perindopril monotherapy, 121 patients were analyzed (62 in group A and 59 in group B). Blood pressure decreased significantly in both groups, but there was no significant change of the eGFR. However, among patients with diabetes, eGFR unchanged in group B (n = 37, 59.1 ± 15.1 vs. 61.2 ± 27.9, P = 0.273), whereas decreased significantly in group A (n = 31, 57.3 ± 16.0 vs. 53.7 ± 16.7, P = 0.005).

Conclusions

In hypertensive patients with diabetic nephropathy, combined therapy with an ACE inhibitor and T/L type calcium antagonist may prevent deterioration of renal function more effectively than an ACE inhibitor/L type calcium antagonist combination.

Effect of N- and T-type calcium channel blocker on proteinuria, blood pressure and kidney function in hypertensive patients: a meta-analysis

The combination of a calcium channel blocker (CCB) and a blocker of the renin-angiotensin-aldosterone system (RAAS) is recommended in clinical practice guidelines. L/N- and L/T-type CCBs might provide an additional effect on lowering proteinuria. Therefore, we conducted a meta-analysis to assess the efficacy of L/N- and L/T-type CCBs in hypertensive patients with proteinuria. We searched MEDLINE, Scopus, Cochrane Central Register of Controlled Trials and ClinicalTrials.gov for single-arm studies and randomized controlled trials (RCTs) that examined the effect of L/N- and L/T-type CCBs as add-on therapy compared with standard antihypertensive regimen for proteinuria on hemodynamic and kidney-related parameters in hypertensive patients with proteinuria. Random-effect model meta-analyses were used to compute changes in the outcomes of interest. We identified 17 RCTs, representing 1905 patients. By meta-analysis, L/N- and L/T-type CCB add-on therapy did not yield significant changes in systolic and diastolic blood pressure compared with standard treatment, but there was a significant lowering of the pulse rate. However, L/N- and L/T-type CCBs resulted in a significant standardized net decrease in albuminuria and proteinuria (-1.01; 95% confidence interval (CI), -1.78 to -0.23; P=0.01), and a standardized net improvement in the estimated glomerular filtration rate and serum creatinine (0.23; 95% CI, 0.11 to 0.35, P<0.001; and -0.25; 95% CI, -0.46 to -0.03; P=0.02, respectively). Despite no additional lowering effect on blood pressure, L/N- and L/T-type CCBs combined with a blocker of the RAAS provided a decrease in proteinuria and improvement in kidney function. Further studies are required to establish the long-term kidney benefits of this combination therapy.

Association between urinary 8-OHdG and pulse wave velocity in hypertensive patients with type 2 diabetes mellitus

INTRODUCTION

Oxidative stress, assessed using 8-hydroxy-2'-deoxyguanosine (8-OHdG), can be associated with arterial stiffness in patients with type 2 diabetes mellitus (T2DM) and/or hypertension (HT). We investigated the correlation between urinary 8-OHdG and pulse wave velocity (PWV) in hypertensive and non-hypertensive T2DM patients with fair glycaemic control to determine the clinical significance of HT as a comorbidity in the diabetic state.

METHODS

Clinical data, including traditional cardiovascular risk factors, diabetic complications, prescribed agents, urinary 8-OHdG level and brachial-ankle PWV, was collected from T2DM patients with and without HT.

RESULTS

There were 76 patients (45 men, 31 women; mean age 61 years; mean haemoglobin A1c level 6.5%) in the study cohort. T2DM patients with HT had significantly higher mean PWV than patients without HT (1,597 cm/s vs 1,442 cm/s; p < 0.05). Patients with HT showed no significant difference in 8-OHdG levels relative to those without HT (median 7.9 ng/mg creatinine vs 8.8 ng/mg creatinine; p > 0.05). Simple linear correlation and stepwise multiple linear regression analyses revealed that 8-OHdG levels correlated independently, significantly and positively with PWV among T2DM patients with HT (r = 0.33, p < 0.05; β= 0.23, p < 0.05). No significant correlation was observed between 8-OHdG levels and PWV among T2DM patients without HT.

CONCLUSION

In the hypertensive state, oxidative stress can be responsible for the development of arterial stiffness, even in patients with fairly well controlled T2DM. Oxidative stress management may be necessary for the prevention of cardiovascular disease in this population.

Azelnidipine, but not amlodipine, reduces urinary albumin excretion and carotid atherosclerosis in subjects with type 2 diabetes: blood pressure control with olmesartan and azelnidipine in Type 2 diabetes (BOAT2 study)

To evaluate the efficacy of azelnidipine and amlodipine on diabetic nephropathy and atherosclerosis, we designed a prospective and randomized controlled clinical study in type 2 diabetic patients with stable glycemic control with fixed dose of anti-diabetic medication. Although there was no difference in blood pressure between both groups, urinary albumin excretion and maximum carotid intima-media thickness were reduced in azelnidipine group, but not in amlodipine group. In addition, inflammatory cytokine levels were decreased only in azelnidipine group which possibly explains such beneficial effects of azelnidipine on urinary albumin excretion and carotid atherosclerosis.

Effects of combination therapy with olmesartan and azelnidipine on serum osteoprotegerin in patients with hypertension

BACKGROUND

Vascular calcification is a potent predictor of plaque instability and cardiac events. Osteoprotegerin (OPG), well-known vascular calcification mediator, is a signaling molecule involved in bone remodeling, which has been implicated in the regulation of vascular calcification and atherogenesis. The purpose of this study was to compare the combination treatments of olmesartan/azelnidipine and olmesartan/diuretics on serum bone-related markers in patients with essential hypertension.

METHODS AND RESULTS

A total of 48 patients with hypertension treated with 20 mg olmesartan were randomized to receive combination treatment with 16 mg azelnidipine (O/A group) or diuretics (1 mg indapamide; O/D group) for 12 months. Osteoprotegerin, matrix metalloproteinase 2 (MMP-2), and high-sensitive CRP (hs-CRP) were measured after 3 and 12 months of treatment. Cardio-ankle vascular index (CAVI) was measured as the arterial stiffness using a VaSera CAVI instrument at the same time points. In both groups, the systolic and diastolic blood pressure reduction is similar. Serum OPG, MMP-2, and hs-CRP were significantly decreased at 12 months in the O/A group (P < .05), while there were no significant reductions in the O/D group. CAVI was significantly improved at 12 months in both the treatment groups. The improvement in CAVI was significantly greater in the O/A group than in the O/D group.

CONCLUSION

Azelnidipine, but not indapamide, combined with olmesartan, improved arterial stiffness and were associated with significant decrease in OPG, MMP-2, and hs-CRP concentrations. These results suggest that the beneficial effects of the combination treatments of olmesartan/azelnidipine on arterial stiffness are mediated by alteration in bone-remodeling and inflammatory markers.

Kidney-protective effects of azelnidipine versus a diuretic in combination with olmesartan in hypertensive patients with diabetes and albuminuria: a randomized study

BACKGROUND

A thiazide diuretic used in combination with benazepril is superior to amlodipine plus benazepril in reducing albuminuria in hypertensive patients with diabetes. However, calcium channel blockers have diverse characteristics. Thus, we investigated whether combining an angiotensin receptor blocker with either azelnidipine or a thiazide diuretic produced similar reductions in albuminuria in hypertensive diabetic patients for the same levels of blood pressure achieved.

METHODS

Hypertensive patients with type 2 diabetes and albuminuria (30-600 mg/g creatinine) under antihypertensive treatment (mean age 67.0±7.6 years) were instructed to stop all antihypertensive treatment and take a combination of olmesartan (20 mg/day) and amlodipine (5 mg/day) for 3 months (run-in period). Then, patients were randomly assigned to receive either olmesartan plus azelnidipine (16 mg/day; n=71) or olmesartan plus trichlormethiazide (1 mg/day; n=72) for an additional 6 months. The primary end point was urinary excretion of albumin at 6 months after randomization.

RESULTS

At the time of randomization, urinary albumin was 116.0 and 107.8 mg/g creatinine (geometric mean) in the azelnidipine and diuretic arms, respectively, and was reduced to a similar extent [79.8 (95% confidence interval 66.4-96.0) and 89.7 (74.6-107.7) mg/g creatinine, respectively, after adjustment for baseline values]. Blood pressure did not differ between the two groups throughout the study period.

CONCLUSIONS

Azelnidipine is equally effective as a thiazide diuretic in reducing urinary albumin when used in combination with olmesartan.

Efficacy and effects on lipid metabolism of combination treatment with losartan + hydrochlorothiazide versus losartan + amlodipine: a 48-week prospective, multicenter, randomized, open-label trial

BACKGROUND

Both combination therapies of an angiotensin II receptor blocker (ARB) with the thiazide diuretic hydrochlorothiazide (HCTZ) and an ARB with a calcium channel blocker (CCB) are recommended to achieve blood pressure (BP) goals in antihypertensive treatment. However, although HCTZ is known to have unfavorable effects on lipid metabolism, the effects of HCTZ in the ARB + HCTZ combination on lipid metabolism have not been fully elucidated.

OBJECTIVE

The aim of this study was to compare the effects on lipid metabolism of combination treatment with the ARB losartan + HCTZ and losartan + the CCB amlodipine and to assess the efficacy in BP lowering of these 2 combination therapies. The metabolism of glucose, uric acid (UA), and high-sensitivity C-reactive protein (hs-CRP), an inflammation marker of atherosclerosis, were also assessed in association with lipid metabolism.

METHODS

This 48-week, prospective, randomized, open-label trial was conducted at 2 clinics and 2 hospitals in Tokorozawa City (Saitama, Japan) and Shinjuku-ku Ward (Tokyo, Japan). Eligible patients had a systolic BP (SBP) >140 mm Hg and/or diastolic BP (DBP) >90 mm Hg despite a >1-month history of monotherapy with an ARB. Patients were randomly assigned to receive losartan 50 mg/d + HCTZ 12.5 mg/d (LOS + HCTZ) or losartan 50 mg/d + amlodipine 5 mg/d (LOS + CCB) for 48 weeks. Follow-up visits were scheduled at 4, 8, 12, 24, and 48 weeks. Biochemical measurements were centrally measured at a single institute. Tolerability and treatment compliance were assessed by physicians every 4 weeks.

RESULTS

A total of 112 patients were enrolled; 26 were excluded from the final analysis, leaving 42 and 44 patients in the LOS + HCTZ and LOS + CCB groups, respectively, included in the final analysis. At 48 weeks, SBP and DBP were significantly decreased in the 2 treatment groups (both, P < 0.0001). The decrease in SBP was significantly greater in the LOS + HCTZ group than in the LOS + CCB group (P < 0.001). The difference in the decrease in DBP between the 2 groups was nonsignificant. There were no significant differences in the changes from baseline (Δ) in any of the lipid parameters between the 2 groups. The decreases at 8 and 12 weeks in LDL-C, TC, and apolipoprotein (apo) B were significantly greater in the LOS + CCB group compared with those in the LOS + HCTZ group. The between-group differences in ΔTG, ΔHDL-C, ΔapoA-1, and ΔapoE throughout the study were nonsignificant. Changes in fasting plasma glucose (FPG), hemoglobin A1c, and hs-CRP were not significantly different between the 2 groups. The between-group difference in ΔUA in men was not significant, but a significant difference was found in women (LOS + HCTZ, 0.74 mg/dL; LOS + CCB, 0.28 mg/dL [P = 0.0017]). No clinically significant adverse events were reported with either treatment throughout the study.

CONCLUSIONS

The findings from the present study suggest that LOS + HCTZ was more efficacious in decreasing SBP than was LOS + CCB in the management of hypertension refractory to ARB monotherapy. Unfavorable effects on lipid metabolism were not observed with either combination therapy.

The combination of OLmesartan and a CAlcium channel blocker (azelnidipine) or candesartan and a calcium channel blocker (amlodipine) in type 2 diabetic hypertensive patients: the OLCA study

Angiotensin II receptor blockers (ARB) are often co-administered with a calcium channel blocker (CCB) for treating hypertension. In this open-label randomised study, untreated diabetic hypertensive patients were randomised to receive either olmesartan 20 mg/day or candesartan 8 mg/day for 12 weeks. Patients with blood pressure exceeding 130/80 mm Hg received add-on 16 mg/day azelnidipine to ongoing olmesartan (OL group) or 5 mg/day amlodipine to ongoing candesartan (CA group) for 24 weeks. Home-measured and clinic-measured blood pressure decreased in both groups. Fasting blood glucose, haemoglobin A1c (HbA1c) and urinary albumin levels decreased significantly in the OL group but not in the CA group. In conclusion, this study revealed clinically relevant differences between two combinations of an ARB+CCB in diabetic hypertensive patients. Olmesartan and azelnidipine had a more persistent early morning antihypertensive effect and produced greater decreases in heart rate, fasting blood glucose and HbA1c (National Glycohemoglobin Standardization Program values) levels, and microalbuminuria than did candesartan and amlodipine.

Association of oxidative DNA damage and C-reactive protein in women at risk for cardiovascular disease

OBJECTIVE

The aim of the current study was to examine the relationship between clinical markers of inflammation and 8-oxo-7,8-dihydro-2'deoxyguanosine (8-oxodG), an oxidative stress marker, in middle-aged women drawn from the HANDLS study, a longitudinal epidemiological study.

METHODS AND RESULTS

We examined commonly assayed markers of inflammation, the DNA base adduct 8-oxodG, a marker of oxidative stress, and cardiovascular risk factors in a cohort of women matched on age and race in 3 groups (n=39 per group) who had low (<3 mg/L) high-sensitivity C-reactive protein (hsCRP), mid (>3-20 mg/L), and high (>20 mg/L) hsCRP. We found a significant relationship between hsCRP level and the oxidative stress marker, 8-oxodG. 8-oxodG was positively correlated with systolic blood pressure, pulse pressure, and interleukin-23. hsCRP was associated with obesity variables, high-density lipoprotein, serum insulin levels, interleukin-12p70 and intracellular adhesion molecule-1. Incubation of primary human endothelial cells with hsCRP generated reactive oxygen species in vitro. Furthermore, hsCRP specifically induced DNA base lesions, but not other forms of DNA damage, including single and double strand breaks.

CONCLUSIONS

These data suggest that in women 8-oxodG is associated with hsCRP and is independently related to select cardiovascular risk factors. Our data in women suggest that hsCRP may contribute to cardiovascular disease by increasing oxidative stress.

Effects of dihydropyridine calcium channel blockers on oxidized low-density lipoprotein induced proliferation and oxidative stress of vascular smooth muscle cells

Background

Dihydropyridine calcium channel blockers (CCBs) are more effective in reducing carotid intima-media thickness (IMT) than other classes of antihypertensive drugs due to their vascular effects. However, the mechanism remains to be elucidated.

Findings

Ox-LDL induced HUVSMCs proliferation in a time- and dose-dependent manner. When pretreated with three CCBs before 50 μg/ml ox-LDL stimulation, 30 μM lacidipine and 3 μM amlodipine exhibited 27% and 18% decrease of pro-proliferative effect induced by ox-LDL, whereas (S-)-amlodipine did not have any anti-proliferative effect. 30 μM lacidipine inhibited about two-thirds of the ox-LDL induced ROS production in HUVSMCs, whereas amlodipine and (S-)-amlodipine did not have influence on ROS production. The MAPKs pathway inhibitors inhibited the ox-LDL induced proliferation of HUVSMCs.

Conclusion

Our study has demonstrated that lipophilic CCBs, such as lacidipine may inhibit ox-LDL induced proliferation and oxidative stress of VSMCs, and that the ROS-MAPKs pathway might be involved in the mechanism.

Effect of erythropoietin-stimulating agent on uremic inflammation

BACKGROUND

The goal of the present study was to explore the effect of medications that are commonly prescribed for CKD patients on uremic state.

METHODS

This was a cross-sectional study. From January 2006 to October 2009, 1,623 patients with end-stage kidney disease (ESKD) commenced hemodialysis (HD) at the 9 participating hospitals. The criteria for exclusion from the database were 1) serum C-reactive protein (CRP) > 3 mg/dL, 2) WBC count > 9,000/mm3 or <4,000/mm3, and 3) patients with cancer, immune complex disease, or vasculitis. A total of 900 patients were entered into the final database. We explored the association of serum CRP just before the first HD session with clinical characteristics, laboratory data, and medications for CKD in the predialysis period.

RESULTS

On univariate analysis, age, CTR, eGFR, and WBC were significantly correlated with CRP. Systolic and diastolic blood pressure, serum albumin, LDL-C, HDL-C, Hb, Cr, and Ca were inversely associated with CRP. Use of erythropoietin-stimulating agents (ESA) using (r = -0.111, p = 0.0015), renin-angiotensin-aldosterone system inhibitors (r = -0.083, p = 0.0154), and calcium channel blockers (r = -0.1, p = 0.0039) was also negatively correlated with CRP. However, only use of ESA showed a significant negative correlation with CRP that was independent of other clinical factors and CKD medications on multiple regression analysis.

CONCLUSION

ESA may strongly reduce uremic inflammation in addition to improving anemia. To confirm this potential effect, a large-scale longitudinal study would be required.

Urinary 8-oxo-7,8-dihydro-2'-deoxyguanosine as a biomarker in type 2 diabetes

The increasing prevalence of diabetes together with the associated morbidity and mortality calls for additional preventive and therapeutic strategies. New biomarkers that can be used in therapy control and risk stratification as alternatives to current methods are needed and can facilitate a more individualized and sufficient treatment of diabetes. Evidence derived from both epidemiological and mechanistic studies suggests that oxidative stress has an important role in mediating the pathologies of diabetic complications. A marker of intracellular oxidative stress that potentially could be used as a valuable biomarker in diabetes is the DNA oxidation marker 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), which can be assessed noninvasively in the urine, with minimal discomfort for the patient. In this review the analytical validity of 8-oxodG is addressed by highlighting important methodological issues. The available epidemiological evidence regarding urinary 8-oxodG and type 2 diabetes is presented. A possible role for DNA oxidation in cancer development in type 2 diabetes patients is discussed, followed by an evaluation of the potential of urinary 8-oxodG as a clinical biomarker in type 2 diabetes.

Effects of calcium channel blockers on glucose tolerance, inflammatory state, and circulating progenitor cells in non-diabetic patients with essential hypertension: a comparative study between azelnidipine and amlodipine on glucose tolerance and endothelial function--a crossover trial (AGENT)

BACKGROUND

Hypertension is associated with impaired glucose tolerance and insulin resistance. Medical treatment that interferes with various steps in the renin-angiotensin system improves glucose tolerance and insulin resistance. However, it remains unclear if long-acting calcium channel blockers (CCBs) such as azelnidipine and amlodipine affect glucose tolerance and insulin resistance in clinical practice.

METHODS

Seventeen non-diabetic patients with essential hypertension who had controlled blood pressure levels using amlodipine (5 mg/day) were enrolled in this study. After randomization, either azelnidipine (16 mg/day) or amlodipine (5 mg/day) was administered in a crossover design for 12-weeks. At baseline and the end of each CCB therapy, samples of blood and urine were collected and 75 g oral glucose tolerance test (OGTT) was performed. In addition, hematopoietic progenitor cells (HPCs) were measured at each point by flow cytometry and endothelial functions were measured by fingertip pulse amplitude tonometry using EndoPAT.

RESULTS

Although blood pressure levels were identical after each CCB treatment, the heart rate significantly decreased after azelnidipine administration than that after amlodipine administration (P < 0.005). Compared with amlodipine administration, azelnidipine significantly decreased levels of glucose and insulin 120 min after the 75 g OGTT (both P < 0.05). Serum levels of high-sensitivity C-reactive protein (P = 0.067) and interleukin-6 (P = 0.035) were decreased. Although endothelial functions were not different between the two medication groups, the number of circulating HPCs was significantly increased after azelnidipine administration (P = 0.016).

CONCLUSIONS

These results suggest that azelnidipine treatment may have beneficial effects on glucose tolerance, insulin sensitivity, the inflammatory state, and number of circulating progenitor cells in non-diabetic patients with essential hypertension.

Angiotensin II receptor blocker and long-acting calcium channel blocker combination therapy decreases urinary albumin excretion while maintaining glomerular filtration rate

Microalbuminuria is a recognized risk factor and predictor for cardiovascular events in patients with hypertension. We analyzed changes in hypotensive effect, urinary albumin excretion (UAE) and estimated glomerular filtration rate (eGFR) in subjects with hypertension and microalbuminuria as a subanalysis of the results of the Nifedipine and Candesartan Combination (NICE-Combi) Study. A total of 86 subjects with essential hypertension with microalbuminuria (UAE <300 mg g(-1) creatinine) were randomly assigned in a double-blind manner to a combination therapy group (standard-dose candesartan at 8 mg per day plus controlled-release (CR) nifedipine 20 mg per day) (n=42) or an up-titrated monotherapy group (candesartan 12 mg per day) (n=44) for 8 weeks of continuous treatment after initially receiving standard-dose candesartan (8 mg per day) monotherapy for 8 weeks (initial treatment). After 8weeks, blood pressure (BP) was significantly reduced in both groups compared with at the end of initial treatment. UAE also showed a significant decrease in the combination therapy group, while there was no significant change of eGFR in either group. A significant positive correlation was seen between BP reduction and UAE after 8 weeks of double-blind treatment in both groups, whereas no significant association was found between ΔUAE and ΔeGFR in either group. These findings show that combination therapy with standard-dose candesartan and nifedipine CR is more effective than up-titrated candesartan monotherapy for reducing BP and improving UAE while maintaining eGFR, and strongly suggest that the combination of an angiotensin II receptor blocker and long-acting calcium channel blocker is beneficial in patients with hypertension and microalbuminuria.

Additive antioxidative effects of azelnidipine on angiotensin receptor blocker olmesartan treatment for type 2 diabetic patients with albuminuria

The present study aimed to determine whether either of two calcium channel blockers affected urinary albumin excretion or urinary levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and liver-type fatty acid-binding protein (L-FABP) in hypertensive diabetic patients with chronic kidney disease (CKD) who were already being treated with maximum doses of the angiotensin II receptor blocker olmesartan. We conducted an open-label, randomized, parallel-controlled study on type 2 diabetic patients with stable glycemic control who were receiving fixed doses of antidiabetic agents. The patients received either 8 mg per day azelnidipine, which was increased up to 16 mg per day (azelnidipine group; n=34), or 2.5 mg per day amlodipine, which was increased up to 5 mg per day (amlodipine group; n=33), over a 24-week period. Mean systolic and diastolic blood pressure decreased significantly in both groups, but there was no significant difference between the two groups at the end of the study. Serum creatinine levels and estimated glomerular filtration rate did not differ significantly between the two groups, whereas the urinary albumin/creatinine ratio and 8-OHdG and L-FABP levels decreased significantly in the azelnidipine group compared with the amlodipine group. Plasma aldosterone level was significantly decreased in the azelnidipine group, and its changes correlated significantly with those of urinary 8-OHdG and L-FABP. Our results suggest that the addition of azelnidipine to the maximal recommended dose of olmesartan was more effective in reducing albuminuria and oxidant stress in hypertensive diabetic patients with CKD than the addition of amlodipine.

Inflammation and therapy for hypertension

It is currently accepted that hypertension, atherosclerosis, and diabetes are disorders with subtle or overt activation of inflammatory mediators. Therefore, it has become increasingly important to ascertain whether current antihypertensive drug families have proinflammatory or anti-inflammatory actions that modify the outcomes of their hemodynamic effects on blood pressure. We review the current state of knowledge about the effects of the major classes of available antihypertensive agents on inflammation and speculate on the possible contribution of these effects to observations in clinical trials. We suggest that a strategy of drug development specifically addressing inflammation in hypertension may provide increased benefit in terms of target organ damage, and we describe some examples of these promising developments.

Urinary albumin excretion during angiotensin II receptor blockade: comparison of combination treatment with a diuretic or a calcium-channel blocker

BACKGROUND

We aimed to test the hypothesis that the angiotensin II receptor blocker (ARB)/diuretic combination decreases the urinary albumin/creatinine ratio (UACR) to a greater extent than treatment with the ARB/calcium-channel blocker (CCB) combination through a mechanism related to a greater reduction of sleep blood pressure (BP).

METHODS

We conducted a prospective, randomized, open-label, blinded end-point trial in hypertensive patients. Patients received olmesartan monotherapy for 12 weeks, followed by an additional use of hydrochlorothiazide (HCTZ) (n = 104) or azelnidipine (n = 103) for 24 weeks after randomization. The measurements of central and ambulatory BP, and laboratory tests were performed at baseline and the end of the study.

RESULTS

The adjusted percent reduction in UACR in the olmesartan/HCTZ group was significantly greater than that in the olmesartan/azelnidipine group (-43.2 vs. -24.0%, P = 0.0014), although the olmesartan/azelnidipine group showed greater decreases in central systolic BP (SBP; P = 0.04), oxidative stress (urinary 8-isoprostane; P = 0.02), inflammation (high-sensitivity C-reactive protein; P = 0.04), and insulin resistance (the homeostasis model assessment insulin resistance index (HOMA(IR)); P < 0.001) than the olmesartan/HCTZ group. In multivariate regression analyses, the significant determinants of change in UACR in the olmesartan/HCTZ group were changes in sleep SBP (P < 0.001), central SBP (P = 0.01), estimated glomerular filtration rate (eGFR) (P = 0.02), and HOMA(IR) (P = 0.03), and those in the olmesartan/azelnidipine group were changes in central SBP (P = 0.001) and urinary 8-isoprostane (P = 0.02).

CONCLUSIONS

These data showed that the ARB/diuretic combination decreased UACR significantly more than the ARB/CCB combination, and this decrease in UACR was associated with a greater magnitude reduction in sleep SBP.

Drug-Induced Changes in Risk/Biomarkers and Their Relationship with Renal and Cardiovascular Long-Term Outcome in Patients with Diabetes

BACKGROUND

Optimal renal and cardiovascular risk management in diabetic patients includes optimal maintenance of blood pressure and control of glucose and lipids. Although the optimal control of these risk factors or “risk/biomarkers” has proven to be effective, it often is difficult to achieve. Consequently, the risk for renal and cardiovascular complications remains devastatingly high. Many risk/biomarkers have been discovered that accurately predict long-term renal and cardiovascular outcome. However, the aim of measuring risk/biomarkers may not be only to determine an individual's risk, but also to use the risk/biomarker level to guide therapy and thereby improve long-term clinical outcome.

CONTENT

This review describes the effects of various drugs on novel risk/biomarkers and the relationship between (drug induced) short-term changes in risk/biomarkers and long-term renal and cardiovascular outcome in patients with diabetes.

SUMMARY

In post hoc analyses of large trials, the short-term reductions in albuminuria, transforming growth factor-β, and N-terminal pro-B–type natriuretic peptide (NT-proBNP) induced by inhibitors of the renin-angiotensin-aldosterone system were associated with a decreased likelihood of long-term adverse renal and cardiovascular outcomes. However, the few studies that systematically investigated the utility of prospectively targeting novel risk/biomarkers such as hemoglobin or NT-proBNP failed to demonstrate long-term cardiovascular protection. The latter examples suggest that although a risk/biomarker may have superior prognostic ability, therapeutically changing such a risk/biomarker does not necessarily improve long-term outcome. Thus, to establish the clinical utility of other novel risk/biomarkers, clinical trials must be performed to prospectively examine the effects of therapeutically-induced changes in single or multiple risk/biomarkers on long-term risk management of patients with diabetes.

Suppressive effects of valsartan on microalbuminuria and CRP in patients with metabolic syndrome (Val-Mets)

The presence of metabolic syndrome (Mets) increases the risk for cardiovascular disease. There is a significant correlation between the levels of urinary albumin to creatinine ratio (UACR) and high-sensitive C-reactive peptide (hs-CRP), and accumulation of each Mets component. Increasing evidence has shown the importance of blockade of renin-angiotensin-systems (RAS) for reducing urinary albumin excretion and hs-CRP levels in Mets patients. However, the impact of RAS blockade on these effects in hypertensive (HT) Mets patients without diabetes mellitus (DM) has not been evaluated. We prospectively measured the levels of UACR and hs-CRP in 153 HT patients with and without Mets. Body weight; waist circumference; presence of dyslipidemia and DM, and levels of HOMA-R, UACR, and hs-CRP were significantly higher in HT patients with Mets than in those without Mets. After we treated these Mets patients with valsartan for 6 months, blood pressure (BP), UACR, and hs-CRP were decreased, whereas body weight, HOMR-R, and the lipid profile were not changed. In HT Mets patients without DM, 6 months after valsartan administration, levels of UACR and hs-CRP were also significantly decreased by 37.8% (-9.0-56.5%, p < 0.05) and 23.6% (-28.7-73.4%, p < 0.05), respectively. However, the percentage change of UACR and hs-CRP was not correlated with the reduction in BP. Valsartan administration lowered increased levels of chronic inflammation in both HT Mets patients with DM and in those without DM. These results indicate that the anti-inflammatory properties of valsartan might also have beneficial effects in Mets patients without DM.

T-type Ca channel blockade as a determinant of kidney protection

Voltage-dependent Ca channels are classified into several subtypes based on the isoform of their α1 subunits. Traditional Ca channels blockers (CCBs), including nifedipine and amlodipine, act predominantly on L-type Ca channels, whereas novel CCBs such as efonidipine, benidipine and azelnidipine inhibit both L-type and T-type Ca channels. Furthermore, cilnidipine blocks L-type and N-type Ca channels. These CCBs exert divergent actions on renal microvessels. L-type CCBs preferentially dilate afferent arterioles, whereas both L-/T-type and L-/N-type CCBs potently dilate afferent and efferent arterioles. The distinct actions of CCBs on the renal microcirculation are reflected by changes in glomerular capillary pressure and subsequent renal injury: L-type CCBs favor an increase in glomerular capillary pressure, whereas L-/T-type and L-/N-type CCBs alleviate glomerular hypertension. The renal protective action of L-/T-type CCBs is also mediated by non-hemodynamic mechanisms, i.e., inhibition of the inflammatory process and inhibition of Rho kinase and aldosterone secretion. Finally, a growing body of evidence indicates that T-type CCBs offer more beneficial action on proteinuria and renal survival rate than L-type CCBs in patients with chronic kidney disease (CKD). Similarly, in CKD patients treated with renin-angiotensin blockers, add-on therapy with N-type CCBs is more potent in reducing proteinuria than that with L-type CCBs, although no difference is found in the subgroup with diabetic nephropathy. Thus, the strategy for hypertension treatment with CCBs has entered a new era: treatment selection depends not only on blood pressure control but also on the subtypes of CCBs.

Cytokine reducing effect of azelnidipine in human peripheral blood mononuclear cells

Numerous clinical trials have shown that calcium channel blocker (CCB) therapy improves the clinical outcome in patients with cardiovascular diseases. Since the progression of several types of cardiovascular diseases is closely associated with inflammation, alleviation of inflammation may be one potential mechanism of those beneficial effects of CCB therapy. We examined whether a new CCB (azelnidipine) could influence the inflammatory response of human peripheral blood mononuclear cells (PBMCs), which are recruited to inflammatory lesions and modulate inflammation. We investigated whether azelnidipine affected intracellular signaling and cytokine production by phytohemagglutinin (PHA)-stimulated human PBMCs in vitro. PBMCs were obtained from 10 healthy volunteers and stimulated with PHA. Then relative intracellular calcium ion concentration ([Ca(2+)](i)) was assessed by fluorescence microscopy, and the production of monocyte chemoattractant protein-1 (MCP-1) and tumor necrosis factor-alpha (TNF-alpha) were measured by enzyme-linked immunosorbent assay. Stimulation with PHA significantly raised [Ca(2+)](i) and enhanced the production of MCP-1 and TNF-alpha by human PBMCs. Azelnidipine significantly diminished the PHA-induced rise of [Ca(2+)](i), and the production of MCP-1 and TNF-alpha. These findings indicate that azelnidipine might have an anti-inflammatory influence on human PBMCs, although the mechanisms and the difference from other CCBs still remain unclear and further exploration should be required.

Peroxynitrite mediates glomerular lesion of diabetic rat via JAK/STAT signaling pathway

BACKGROUND

Peroxynitrite, a highly reactive oxidant produced by the reaction of nitric oxide with free radicals superoxide, has been indicated to be involved in many diseases. However, the contributions of peroxynitrite to diabetic nephropathy and the underlying mechanism have not been fully explored.

AIM

The present study was designed to evaluate the role and the underlying mechanism of peroxynitrite in glomerular lesion of diabetic rat.

METHODS

Diabetes was induced in male Wistar rats by i.p. injection of streptozotocin, and urate was used as a specific scavenger of peroxynitrite; the pathological changes of rat glomerulus were evaluated by hematoxylin and eosin, periodic acid-Schiff staining and transmission electron microscopy observation; immunohistochemistry and Western blot were used to detect the content of nitrotyrosine (the marker of peroxynitrite) in renal cortex; the expression levels of tyrosine phosphorylation of JAK2, STAT1, and STAT3 were assessed by Western blot assay; RT-PCR and Western blot were used to assay expression levels of transforming growth factor (TGF)-beta1 and fibronectin; biochemical indicators of renal function were also detected.

RESULTS

The content of nitrotyrosine was increased, consistent with the pathological changes of glomerulus and renal dysfunction in the diabetes group. Urate prevented the formation of nitrotyrosine in rat glomerulus and attenuated the pathological alterations. Furthermore, urate inhibited the activation of JAK2, STAT1, and STAT3. Finally, homogenates from renal cortices demonstrated reduced expression of TGF- beta1 and fibronectin under urate treatment.

CONCLUSIONS

Our findings thus provides in vivo evidence that exaggerated peroxynitrite formation mediates the glomerular lesion in, at least, Type 1 diabetes, which may function through JAK/STAT signaling pathway.

Irbesartan-mediated reduction of renal and cardiac damage in insulin resistant JCR : LA-cp rats

BACKGROUND AND PURPOSE

Angiotensin II receptor antagonists (ARBs), originally developed for antihypertensive properties, have pleiotropic effects including direct vascular actions. We tested the hypothesis that the ARB irbesartan would be effective against micro- and macrovascular complications of the prediabetic metabolic syndrome using the obese, insulin-resistant JCR : LA-cp rat that exhibits micro- and macrovascular disease with ischaemic myocardial lesions and renal disease.

EXPERIMENTAL APPROACH

Obese male rats were treated with irbesartan (30 mg.kg(-1).day(-1), incorporated into chow) from 12 to 25 weeks of age.

KEY RESULTS

Irbesartan treatment caused no change in food intake or body weight. Fasting glycaemic control of the JCR : LA-cp rats was marginally improved, at the expense of increased plasma insulin levels ( approximately 50%). Fasting plasma triglycerides were marginally reduced ( approximately 25%), while cholesterol concentrations were unchanged. Elevated concentrations of adiponectin, monocyte chemotactic protein-1 and plasminogen activator inhibitor-1 were reduced along with severity of glomerular sclerosis. Macrovascular dysfunction (aortic hypercontractile response to noradrenergic stimulus and reduced endothelium-dependent relaxation) was improved and frequency of ischaemic myocardial lesions reduced (62%).

CONCLUSIONS AND IMPLICATIONS

Irbesartan reduces markers of inflammation and prothombotic status, improves macrovascular function and reduces glomerular sclerosis and myocardial lesions in a model of the metabolic syndrome. Unlike pharmaceutical agents targeted on metabolic dysfunction, irbesartan reduced end-stage disease without major reduction of plasma lipids or insulin. The protective effects appear to be secondary to unknown intracellular mechanisms, probably involving signal transduction pathways. Understanding these would offer novel pharmaceutical approaches to protection against cardiovascular disease.

Angiotensin-II receptor antagonist combined with calcium channel blocker or diuretic for essential hypertension

To achieve the target blood pressure recommended by the latest guidelines, multiple antihypertensive drugs are needed in most patients. In this study, the efficacy of treatment using an angiotensin II receptor antagonist (ARB) combined with a calcium channel blocker (CCB) or a diuretic was compared from multiple perspectives in patients with hypertension. Twenty-nine patients with essential hypertension, who had failed to achieve their target blood pressure (<130/85 mm Hg for patients <65 years old and <140/90 mm Hg for those >/=65 years) when treated with the ARB olmesartan at 20 mg day(-1), were additionally given 8-16 mg day(-1) of the CCB azelnidipine or 1-2 mg day(-1) of trichlormethiazide (a thiazide diuretic) in a randomized crossover manner for 4 months each. At the end of each combination therapy period, blood and urine samples were collected and arterial stiffness was evaluated by measuring the cardio-ankle pulse wave velocity. Compared with monotherapy, the blood pressure was reduced similarly by adding azelnidipine (-12/-10 mm Hg) or trichlormethiazide (-14/-9 mm Hg). The heart rate was decreased with the CCB by 4 b.p.m. (P<0.05), whereas it was unchanged with the thiazide. Serum K, lipids and blood glucose were not significantly changed with either combination, whereas serum uric acid was increased with the thiazide (P<0.01) but was unchanged with azelnidipine. Plasma levels of renin, angiotensin II and aldosterone were also increased with the thiazide period, whereas high-sensitivity C-reactive protein and oxidized low-density lipoprotein were decreased with azelnidipine. In addition, the cardio-ankle vascular index, a parameter of arterial stiffness, was decreased with the azelnidipine period but was unchanged with the thiazide period (P<0.01). It is suggested that the combination of olmesartan and azelnidipine has advantages over the combination of olmesartan and a thiazide with respect to avoiding hyperuricemia, sympathetic activation, renin-angiotensin-aldosterone system stimulation, inflammation, oxidative stress, and increased arterial stiffness in patients with moderate hypertension. These properties may provide cardiovascular protection in addition to the hypotensive effect.