Dual blockade of the RAS is superior to maximal recommended dose of ACE inhibitors with regard to lowering of albuminuria and blood pressure in type 1 patients with DN. Long-term trials are needed to further establish the role of dual blockade of the RAS in renal and cardiovascular protection.

Abstract. Albuminuria and hypertension are predictors of poor renal and cardiovascular outcome in diabetic patients. This study tested whether dual blockade of the renin-angiotensin system (RAS) with both an angiotensin-converting enzyme (ACE) inhibitor (ACE-I) and an Angiotensin-II receptor blocker (ARB) is superior to either drug alone in type I diabetic patients with diabetic nephropathy (DN). A randomized double-blind crossover trial was performed with 8-wk treatment with placebo, 20 mg of benazepril once daily, 80 mg of valsartan once daily, and the combination of 20 mg of benazepril and 80 mg of valsartan. Twenty type I diabetic patients with DN were included. At the end of each treatment period, albuminuria, 24-h BP, and GFR were measured. Eighteen patients completed the study. Placebo values were: albuminuria [mean (95% CI)], 701 (490 to 1002) mg/24 h; BP [mean (SEM)], 144 (4)/79 (2) mmHg, and GFR [mean (SEM)], 82 (7) ml/min per 1.73 m 2 . Treatment with benazepril, valsartan, or dual blockade significantly reduced albuminuria and BP compared with placebo. Benazepril and valsartan were equally effective. Dual blockade induced an additional reduction in albuminuria of 43 % (29 to 54 %) compared with any type of monotherapy, and a reduction in systolic BP of 6 (0 to 13) mmHg and 7 (1 to 14) mmHg (versus benazepril and valsartan, respectively) and a reduction of 7 (4 to 10) mmHg diastolic compared with both monotherapies. GFR was reversibly reduced on dual blockade compared with monotherapy and placebo. All treatments were safe and well tolerated. In conclusion, dual blockade of the RAS may offer additional renal and cardiovascular protection in type I diabetic patients with DN.Albuminuria and hypertension are predictors of poor renal and cardiovascular outcome in patients with diabetes (1,2). Antihypertensive treatment, especially ACE-I, has been shown to reduce albuminuria, to diminish loss of kidney function, and to improve survival in type I patients with DN (1-3). Studies of diabetic and nondiabetic kidney disease suggest the initial degree of reduction in albuminuria after blockade of the reninangiotensin system (RAS) predicts an attenuated rate of decline in GFR, as reviewed by Rossing (1). As a consequence, albuminuria may serve as a surrogate end point for monitoring treatment efficacy and prognosis in DN (4).A superior effect on BP and a tendency toward a more pronounced drop in urinary albumin excretion of dual blockade of the RAS compared with single blockade has been reported in type II patients with microalbuminuria (5). We have recently shown additional drop in albuminuria and diastolic BP when adding an angiotensin receptor blocker (ARB) to angiotensinconverting enzyme inhibitor (ACE-I) treatment in type l patients with albuminuria Ͼ1 g/24 h and BP Ͼ135/85 mmHg, despite conventional antihypertensive therapy including three different agents (6). However, this subgroup is highly selected; therefore, it may differ from the patients in general with DN, especially with regard to RAS activity and ...

OBJECTIVE -We evaluated the renoprotective effects as reflected by short-term changes in albuminuria of dual blockade of the renin-angiotensin system (RAS) by adding an angiotensin II receptor blocker (ARB) to treatment with maximal recommended doses of an ACE inhibitor (ACEI) in patients with type 2 diabetes and nephropathy. RESEARCH DESIGN AND METHODS -A total of 20 patients (17 men and 3 women)with type 2 diabetes along with hypertension and nephropathy were enrolled in this doubleblind, randomized, two-period, crossover trial of 8 weeks of treatment with the ARB candesartan 16 mg daily and placebo added in random order to existing treatment with lisinopril/enalapril 40 mg daily or captopril 150 mg daily. At the end of each treatment period, we evaluated albuminuria in three 24-h urinary collections by turbidimetry, 24-h ambulatory blood pressure (ABP) using the Takeda-TM2420, and glomerular filtration rate (GFR) by the 51 Cr-EDTA plasmaclearance technique.RESULTS -During monoblockade of the RAS by ACEI treatment, albuminuria was 706 (349Ϫ1,219) mg/24 h [geometric mean (IQR)]; 24-h ABP was 138 Ϯ 3/72 Ϯ 2 mmHg (mean Ϯ SE); and GFR was 77 Ϯ 6 ml ⅐ min Ϫ1 ⅐ 1.73 m Ϫ2 (mean Ϯ SE). During dual blockade of the RAS by addition of candesartan 16 mg daily, there was a mean (95% CI) reduction in albuminuria of 28 (17Ϫ38) compared with ACEI alone (P Ͻ 0.001). There was a modest reduction in systolic/ diastolic 24-h ABP of 3/2 mmHg (Ϫ2 to 8 systolic, Ϫ2 to 5 diastolic; NS). Changes in albuminuria did not correlate to changes in ABP. Addition of candesartan 16 mg daily induced a small, insignificant decrease in GFR of 4 (Ϫ1 to 9) ml ⅐ min -1 ⅐ 1.73 m -2 .CONCLUSIONS -Dual blockade of the RAS provides superior short-term renoprotection independent of systemic blood pressure changes in comparison with maximally recommended doses of ACEI in patients with type 2 diabetes as well as nephropathy. Diabetes Care 26:2268 -2274, 2003D iabetic nephropathy occurs in 30 -40% of all diabetic patients and has become the leading cause of endstage renal disease in the western world (1). In diabetic patients, albuminuria independently predicts poor renal and cardiovascular outcome (1). Several clinical studies have clearly demonstrated that blockade of the renin-angiotensin system (RAS), either by an ACE inhibitor (ACEI) or an angiotensin II receptor blocker (ARB), reduces albuminuria, retards the progressive loss in renal function, and improves survival (2-7). The antiproteinuric response upon blockade of the RAS has been demonstrated to predict the subsequent long-term rate of decrease in glomerular filtration rate (GFR), i.e., the greater the initial decrease in albuminuria, the less the long-term decrease in kidney function (8,9). Consequently, the short-term reduction in albuminuria may serve to monitor treatment efficacy and long-term prognosis in diabetic nephropathy, and it has previously been advocated that albuminuria should be reduced as far as possible to obtain maximal renoprotective effects (10).Despite the proven benefit of ...

BackgroundDespite intensive insulin treatment, many patients with type-1 diabetes (T1DM) have longstanding inadequate glycaemic control. Metformin is an oral hypoglycaemic agent that improves insulin action in patients with type-2 diabetes. We investigated the effect of a one-year treatment with metformin versus placebo in patients with T1DM and persistent poor glycaemic control.Methodology/Principal FindingsOne hundred patients with T1DM, preserved hypoglycaemic awareness and HaemoglobinA1c (HbA1c) ≥8.5% during the year before enrolment entered a one-month run-in on placebo treatment. Thereafter, patients were randomized (baseline) to treatment with either metformin (1 g twice daily) or placebo for 12 months (double-masked). Patients continued ongoing insulin therapy and their usual outpatient clinical care. The primary outcome measure was change in HbA1c after one year of treatment. At enrolment, mean (standard deviation) HbA1c was 9.48% (0.99) for the metformin group (n = 49) and 9.60% (0.86) for the placebo group (n = 51). Mean (95% confidence interval) baseline-adjusted differences after 12 months with metformin (n = 48) versus placebo (n = 50) were: HbA1c, 0.13% (−0.19; 0.44), p = 0.422; Total daily insulin dose, −5.7 U/day (−8.6; −2.9), p<0.001; body weight, −1.74 kg (−3.32; −0.17), p = 0.030. Minor and overall major hypoglycaemia was not significantly different between treatments. Treatments were well tolerated.Conclusions/SignificanceIn patients with poorly controlled T1DM, adjunct metformin therapy did not provide any improvement of glycaemic control after one year. Nevertheless, adjunct metformin treatment was associated with sustained reductions of insulin dose and body weight. Further investigations into the potential cardiovascular-protective effects of metformin therapy in patients with T1DM are warranted.Trial RegistrationClinicalTrials.gov NCT00118937