Maximum renal responses to renin inhibition in healthy study participants: VTP-27999 versus aliskiren.

Background: Renin inhibition with aliskiren induced the largest increases in renal plasma flow (RPF) in salt-depleted healthy volunteers of all renin-angiotensin system (RAS) blockers. However, given its side-effects at doses higher than 300 mg, no maximum effect of renin inhibition could be established. We hypothesized that VTP-27999, a novel renin inhibitor without major side-effects at high doses, would allow us to establish this.

Habitual flavonoid intake and endothelial function in healthy humans.

Objective: Endothelial function, as measured by noninvasive techniques, is known to vary widely within populations. Our study was designed to test the hypothesis that this variation is determined in large part by a person's habitual dietary intake of flavonoids.

Methods: This was an analytical study examining the relationship between endothelial function and dietary flavonoids in 19 healthy older adults (mean age 72 years).

Impact of glycaemic control on the effect of direct renin inhibition in the AVOID study.

Introduction: Hyperglycaemia induces development and progression of microvascular complications in diabetes. A direct link between high glucose levels and intrarenal renin-angiotensin activation has been demonstrated. This post-hoc analysis assessed the influence of baseline glycaemic control on the reduction of albuminuria with aliskiren or placebo added to losartan in the Aliskiren in the EValuation of PrOteinuria In Diabetes (AVOID) study.

Renal responses to three types of renin-angiotensin system blockers in patients with diabetes mellitus on a high-salt diet: a need for higher doses in diabetic patients?

Objective: Activation of the renal renin-angiotensin system in patients with diabetes mellitus appears to contribute to the risk of nephropathy. Recently, it has been recognized than an elevation of prorenin in plasma also provides a strong indication of risk of nephropathy. This study was designed to examine renin-angiotensin system control mechanisms in the patient with diabetes mellitus.

Evaluation of a direct prorenin assay making use of a monoclonal antibody directed against residues 32-39 of the prosegment.

Background: Prorenin is an early marker of microvascular complications in diabetes. However, it can only be measured indirectly (following its conversion to renin), with a renin immunoradiometric assay (IRMA). Unfortunately, treatment with a renin inhibitor interferes with this assay, because renin inhibitors induce a conformational change in prorenin, thereby allowing its detection as renin.

Varying patterns of the antihypertensive and antialbuminuric response to higher doses of renin-angiotensin-aldosterone system blockade in albuminuric hypertensive type 2 diabetes mellitus patients.

Objective: In patients with type 2 diabetes mellitus (T2DM), blocking of the renin-angiotensin-aldosterone system (RAAS) has demonstrated efficacy in lowering blood pressure (BP) and urinary albumin excretion rate (UAER). Nonetheless, not all patients successfully respond to RAAS blockade with a reduction in BP and UAER.

Methods: This secondary analysis of a double-blind study of 391 patients with T2DM assessed the importance of using higher doses of the RAAS blocker valsartan to improve the BP and UAER response in patients initially identified as prompt or delayed responders.

Impact of aliskiren treatment on urinary aldosterone levels in patients with type 2 diabetes and nephropathy: an AVOID substudy.

Introduction: Aldosterone blockade reduces albuminuria in diabetic patients with chronic kidney disease (CKD), and improves prognosis in chronic heart failure. This study assessed the effects of direct renin inhibition with aliskiren in combination with losartan and optimal antihypertensive therapy on urinary aldosterone, plasma renin activity (PRA) and plasma renin concentration (PRC).

Materials And Methods: In the AVOID study, 599 patients with type 2 diabetes, hypertension and nephropathy received 6 months aliskiren (150 mg force titrated to 300 mg once daily after 3 months) or placebo added to losartan 100 mg and optimal antihypertensive therapy.

Aliskiren in combination with losartan reduces albuminuria independent of baseline blood pressure in patients with type 2 diabetes and nephropathy.

Background And Objectives: Elevated BP contributes to development and progression of proteinuria and decline in renal function in patients with type 2 diabetes. Our post hoc analysis assessed the baseline BP influence on the antiproteinuric effect in the Aliskiren in the Evaluation of Proteinuria in Diabetes (AVOID) study.

Design, Setting, Participants, & Measurements: In the AVOID study, 599 hypertensive type 2 diabetic patients with nephropathy received 6 months of aliskiren (150 mg force titrated to 300 mg daily after 3 months) or placebo added to losartan (100 mg) daily and optimal antihypertensive therapy.

Impact of baseline renal function on the efficacy and safety of aliskiren added to losartan in patients with type 2 diabetes and nephropathy.

Objective: Proteinuric diabetic patients with reduced glomerular filtration rate (GFR) are at high risk of renal and cardiovascular disease progression and treatment-related adverse events. This post hoc analysis assessed the efficacy and safety of aliskiren added to the maximal recommended dose of losartan according to baseline estimated GFR (eGFR) (stage 1-3 chronic kidney disease [CKD]).

Research Design And Methods: In the Aliskiren in the Evaluation of Proteinuria in Diabetes (AVOID) study, 599 hypertensive patients with type 2 diabetes and nephropathy received 6 months of aliskiren (150 mg daily titrated to 300 mg daily after 3 months) or placebo added to 100 mg losartan and optimal antihypertensive therapy.

Brain blood flow and velocity: correlations between magnetic resonance imaging and transcranial Doppler sonography.

Objective: Because transcranial Doppler sonography (TCD) is unable to measure arterial diameter, it remains unproven whether the changes in cerebral blood velocity it measures are representative of changes in cerebral blood flow (CBF). Our study was designed to compare velocity changes with flow changes measured by two magnetic resonance imaging (MRI) techniques, perfusion MRI and arterial spin labeling (ASL), using flavanol-rich cocoa to induce CBF changes in healthy volunteers.

Methods: We enrolled 20 healthy volunteers aged 62 to 80 years (mean, 73 years).

Renal plasma flow: glomerular filtration rate relationships in man during direct renin inhibition with aliskiren.

We examined the relation between change in renal plasma flow (RPF) and change in glomerular filtration rate (GFR) in healthy humans on a low-salt diet during direct renin inhibition with aliskiren. We measured the renal hemodynamic response to acute dosing of 300mg aliskiren by mouth to 19 healthy normotensive subjects (age, 33+/-3 years; baseline RPF, 575+/-23; GFR, 138+/-14mL/min/1.73m(2)) on a low-sodium diet (10mmol/day).

Flavanols, the Kuna, cocoa consumption, and nitric oxide.

The Kuna Indians, who reside in an archipelago on the Caribbean Coast of Panama, have very low blood pressure (BP) levels, live longer than other Panamanians, and have a reduced frequency of myocardial infarction, stroke, diabetes mellitus, and cancer-at least on their death certificates. One outstanding feature of their diet includes a very high intake of flavanol-rich cocoa. Flavonoids in cocoa activate nitric oxide synthesis in healthy humans.

Direct renin inhibition and the kidney.

Direct renin inhibition is a new means for blocking the renin-angiotensin system at the rate-limiting step of the cascade of events triggered by renin release--the interaction of renin with its physiological substrate angiotensinogen. The remarkable success of angiotensin-converting-enzyme inhibitors and angiotensin receptor blockers in the management of cardiovascular and renal disease has led to great interest in the potential of direct renin inhibitors. This Review focuses on the evidence that suggests that direct renin inhibitors might block the renin-angiotensin system in the kidney more completely than either angiotensin-converting-enzyme inhibitors or angiotensin receptor blockers.

Antihypertensive effects of double the maximum dose of valsartan in African-American patients with type 2 diabetes mellitus and albuminuria.

Objective: The blood pressure (BP)-lowering response to renin-angiotensin-aldosterone system blockade in hypertensive African-Americans is typically less than in whites. To determine whether higher than conventional doses of renin-angiotensin-aldosterone system blockade can improve BP reduction in African-American patients.

Methods: Hypertensive patients with type 2 diabetes and albuminuria were enrolled: 110 African-Americans (BP = 150/87 mmHg, aged 57.

A comparison of prediction equations for estimating glomerular filtration rate in pregnancy.

Objective: To compare existing glomerular filtration rate (GFR) prediction equations with the gold standard, inulin clearance, in pregnancy.

Methods: Five equations were assessed for precision, bias, and accuracy in prediction of true GFR, measured by inulin clearance in 12 healthy, pregnant women during the second (T2) and third (T3) trimesters and in postpartum (PP).

Results: Precision was greatest with 24-hour creatinine clearance estimation of GFR (R(2) = 13% (T2), R(2) = 26% (T3)).

[Aliskiren combined with losartan in type 2-diabetes and nephropathy - secondary publication].

We evaluated the renoprotective effects of adding aliskiren to treatment with losartan in hypertensive patients with type 2 diabetes and nephropathy. A total of 599 patients were randomized to six months of treatment with placebo or aliskiren in addition to losartan 100 mg and optimal antihypertensive therapy. The primary outcome was a reduction in the urinary albumin-creatinine ratio.

Cocoa and cardiovascular health.

Epidemiological data demonstrate that regular dietary intake of plant-derived foods and beverages reduces the risk of coronary heart disease and stroke. Among many ingredients, cocoa might be an important mediator. Indeed, recent research demonstrates a beneficial effect of cocoa on blood pressure, insulin resistance, and vascular and platelet function.

Aliskiren accumulates in Renin secretory granules and binds plasma prorenin.

The vascular effects of aliskiren last longer than expected based on its half life, and this renin inhibitor has been reported to cause a greater renin rise than other renin-angiotensin system blockers. To investigate whether aliskiren accumulation in secretory granules contributes to these phenomena, renin-synthesizing mast cells were incubated with aliskiren, washed, and exposed to forskolin in medium without aliskiren (0.1 to 1000 nmol/L).

Cerebral blood flow response to flavanol-rich cocoa in healthy elderly humans.

Background And Purpose: Cerebral ischemia is a common, morbid condition accompanied by cognitive decline. Recent reports on the vascular health benefits of flavanol-containing foods signify a promising approach to the treatment of cerebral ischemia. Our study was designed to investigate the effects of flavanol-rich cocoa (FRC) consumption on cerebral blood flow in older healthy volunteers.

Renal and hormonal responses to direct renin inhibition with aliskiren in healthy humans.

Background: Pharmacological interruption of the renin-angiotensin system focuses on optimization of blockade. As a measure of intrarenal renin activity, we have examined renal plasma flow (RPF) responses in a standardized protocol. Compared with responses with angiotensin-converting enzyme inhibition (rise in RPF approximately 95 mL x min(-1) x 1.

Aliskiren combined with losartan in type 2 diabetes and nephropathy.

Background: Diabetic nephropathy is the leading cause of end-stage renal disease in developed countries. We evaluated the renoprotective effects of dual blockade of the renin-angiotensin-aldosterone system by adding treatment with aliskiren, an oral direct renin inhibitor, to treatment with the maximal recommended dose of losartan (100 mg daily) and optimal antihypertensive therapy in patients who had hypertension and type 2 diabetes with nephropathy.

Methods: We enrolled 599 patients in this multinational, randomized, double-blind study.