Coadministration of losartan and enalapril exerts additive antiproteinuric effect in IgA nephropathy. ACE inhibitors and persistent left ventricular hypertrophy after renal transplantation: a randomized clinical trial. ACE inhibition reduces proteinuria in normotensive patients with IgA nephropathy: a multicentre, randomized, placebo-controlled study. Treatment of IgA nephropathy with ACE inhibitors: a randomized and controlled trial. Efficacy of ACE inhibitors and ATII receptor blockers in patients with microalbuminuria: a prospective study. ACE inhibitor mediated reductions in renal size and microalbuminuria in normotensive, diabetic subjects. A randomized trial of captopril for microalbuminuria in normotensive adults with sickle cell anemia. alpha1-Proteinase inhibitor therapy for the prevention of chronic lung disease of prematurity: a randomized, controlled trial. Distinct time courses of renal protective action of angiotensin receptor antagonists and ACE inhibitors in chronic renal disease.
Angiotensin-converting enzyme (ACE) inhibitors and AT1-receptor antagonists (ARAs) are widely administered to reduce urinary protein loss and slow the progression of proteinuric nephropathy to end-stage renal failure. Our group recently observed that the combination of ACE inhibitors and ARAs may have an additive antiproteinuric effect, which may occur because ACE inhibitors do not completely reduce angiotensin II (Ang II) production. Ang II is also produced by chymase. Thus, combination therapy better antagonizes the effects of Ang II. The purpose of this study is to ascertain whether the additive antiproteinuric effect of ACE inhibitors plus ARAs is dose dependent and related to the drug-induced reduction in systemic blood pressure. Therefore, enalapril (E; 10 mg/d) and losartan (LOS; 50 mg/d) were randomly administered alone and then in association; initial dosages were doubled when drugs were administered alone and in association. To determine the influence of the drug-dependent effect on reducing blood pressure and the reduction in urinary proteinuria, both ambulatory and office blood pressures were recorded. E and LOS administered alone reduced proteinuria by the same extent; no further reduction was observed when E and LOS alone were administered at a doubled dose. When E and LOS were coadministered, proteinuria decreased by a greater extent compared with E and LOS alone; an additional reduction in proteinuria was observed when combined therapy doses were doubled. The reduction in proteinuria was not correlated with clinical through blood pressure; however, reductions in diastolic and mean ambulatory blood pressures significantly correlated with the decrease in proteinuria, as well as with creatinine clearance. In conclusion, this study shows that combination therapy with E and LOS has an additive dose-dependent antiproteinuric effect that is likely induced by the drug-related reduction in systemic blood pressure. In normotensive proteinuric patients, it is likely that even a small reduction in systemic blood pressure may affect intraglomerular hemodynamics by a great extent because efferent arteriole regulation is hampered more completely by the coadministration of ACE inhibitors and ARAs. Interventional studies of left ventricular hypertrophy (LVH) in renal transplant recipients are scarce and to date evaluated only patients immediately after renal transplantation.
                Randomized controlled trial that assessed the effectiveness of angiotensin-converting enzyme (ACE) inhibitors in regressing persistent LVH after successful transplantation.
                70 renal transplant recipients (47 men; age, 30 to 68 years) without diabetes previously randomly assigned to either cyclosporine or tacrolimus therapy, with LVH persisting 3 to 6 months after transplantation.
                Subjects were randomly assigned to either lisinopril (ACE-inhibitor group; 36 patients) or no therapy (control group; 34 subjects).
                Main outcome was change in left ventricular mass index (LVMi) at month 18.
                A consistent decrease in both systolic (SBP) and diastolic blood pressure (DBP) was observed in both groups (between-group differences, -1.7 +/- 3.3 mm Hg; 95% confidence interval [CI], -4.8 to 8.2; P = 0.6 for SBP; 0.3 +/- 2.2 mm Hg; 95% CI, -4.8 to 4.1; P = 0.9 for DBP), whereas LVMi regressed more in the ACE-inhibitor group (between-group difference, 10.1 +/- 16.3 g/m(2.7); 95% CI, 4.2 to 16.1; P < 0.01). A significant interaction of ACE inhibitors with cyclosporine in affecting LVMi change was shown by means of post hoc multiple regression analysis (P < 0.01; differences between cyclosporine and tacrolimus group, 13.3 +/- 3.9 g/m(2.7); 95% CI, 5.3 to 21.2; P < 0.01 in the ACE-inhibitor group; 3.7 +/- 4.2 g/m(2.7); 95% CI, -4.7 to 12.2; P = 0.4 in the control group).
                Single-center study with small sample size. Interaction of ACE inhibitors with cyclosporine treatment emerged from post hoc analysis.
                A prolonged course of ACE-inhibitor therapy is effective in regressing the persistent LVH of renal transplant recipients by mechanisms independent of effects on BP. This regression seems to be at least in part the effect of an interaction between ACE inhibitors and cyclosporine. A multicentre, randomized, placebo-controlled study was performed in 39 adult patients with biopsy-proven IgA nephropathy with the aim of comparing the effects of the ACE inhibitor fosinopril and placebo on proteinuria. All patients had normal blood pressure and normal renal function. Proteinuria ranged from 1.0 to 2.5 g/24 h. After a 3-month run-in period, fosinopril and placebo were randomly administered in two 4-month sequences separated from cross-over treatment by a 1-month interval. The mean values of creatinine clearance did not change during either the placebo or the treatment sequences. The mean values of mean arterial pressure (MAP) were significantly lower during the fosinopril sequence (90.4 +/- 9.0 mmHg) than in basal conditions (92.8 +/- 9.1 mmHg) (P = 0.034). The mean basal values of proteinuria were 1.74 +/- 0.84 g/24 h. They were unchanged during the placebo sequence (1.79 +/- 1.20) and fell to 1.37 +/- 0.98 g/24 h after 4 months of fosinopril treatment. Using a multivariate statistical analysis, the treatment effect by time on proteinuria was significantly evident only in the fosinopril sequence (Wilks test, P = 0.033). Changes in protein excretion were not correlated with changes in MAP, baseline plasma renin activity, and urinary sodium excretion. This controlled study shows that fosinopril can significantly reduce proteinuria even in normotensive patients with IgA nephropathy. Obviously, the results of treatment with ACE inhibitors on long-term renal prognosis remain to be elucidated. Some retrospective studies have suggested a beneficial influence of angiotensin-converting enzyme (ACE) inhibitors on the progression of IgA nephropathy (IgAN), but prospective and controlled studies demonstrating this effect are lacking. Forty-four patients with biopsy-proven IgAN, proteinuria > or = 0.5 g/d, and serum creatinine (SCr) < or = 1.5 mg/dl were randomly assigned either to receive enalapril (n = 23) or to a control group (n = 21) in whom BP was controlled with antihypertensives other than ACE inhibitors. Primary outcome was renal survival estimated by a 50% increase in baseline SCr. Secondary outcomes were the presence of a SCr > 1.5 mg/dl at the last visit and the evolution of proteinuria. Baseline clinical findings were similar at baseline between enalapril-treated and control group, and there were no differences in BP control during follow-up. Mean follow-up was 78 +/- 37 mo in the enalapril group and 74 +/- 36 mo in the control group. Three patients (13%) in the enalapril group and 12 (57%) in the control group reached the primary end point (P < 0.05). Kaplan-Meier renal survival was significantly better in enalapril group than in control group: 100% versus 70% after 4 yr and 92% versus 55% after 7 yr (P < 0.05). Three patients in the enalapril group (13%) and 11 (52%) in the control group showed SCr > 1.5 mg/dl at the last visit (P < 0.05). Proteinuria significantly decreased in the enalapril group, whereas it tended to increase in the control group (P < 0.001 between groups). In conclusion, ACE inhibitors significantly improve renal survival in proteinuric IgAN with normal or moderately reduced renal function. We compared the efficacy of treatment protocols with an angiotensin converting enzyme (ACE) inhibitor alone (enalapril, 5 mg) or angiotensin II (ATII) receptor blocker (losartan, 50 mg) or both enalapril plus losartan in patients with microalbuminuria in a prospective, randomized clinical trial. Normotensive type 2 diabetic patients with microalbuminuria documented by at least 3 consecutive urinary albumin excretion analyses were recruited for the study. Patients were grouped randomly into one of the protocols which consisted of treatment with 5 mg enalapril daily (group 1; n=12), 50 mg losartan daily (group 2; n=12) or both drugs (group 3; n=10). They were reevaluated with regard to HbA1c levels, lipid profiles, blood pressure and urinary albumin excretion rates (UAER) at 3-month intervals for 12 months. Mean age, duration of diabetes, body mass index, plasma lipid profiles and blood pressure levels were similar at the initial visit. In group 1, UAER returned to normal levels in 10 patients. Normalization of UAER occurred in 8 and 7 patients in groups 2 and 3, respectively. Percentage of reduction in UAERs at the end of 12 months were 58%, 59% and 60% (p=0.0001; p=0.0002; p=0.0003, respectively). The amount of reduction in UAER did not differ significantly among the three groups (p=0.346). ACE inhibitors and angiotensin II receptor blockers have similar efficacy in treating diabetic microalbuminuria, and the combination of the two drugs does not add any further benefit. Recent studies utilizing converting enzyme inhibitors (CEI) in diabetic rats document reductions in both renal hypertrophy and albuminuria. Four separate clinical studies in normotensive patients with diabetes demonstrate reduction of microalbuminuria with CEIs independent of blood pressure reduction. The present pilot study examines the results of reducing an elevated glomerular filtration rate on changes in renal size and microalbuminuria in normotensive, hyperfiltering insulin-dependent diabetic (IDDM) patients. Fifteen IDDM patients were randomized to either placebo or the CEI, lisinopril. Dosage of lisinopril was titrated over 3 months to reduce glomerular filtration rate (GFR) to < or = 2.33 mL/sec. Evaluation at 18 months demonstrated the lisinopril group had a marked reduction in renal size (16.9 +/- 1.1, baseline versus 12.8 +/- 0.9 cm, 18 months; p < 0.05) and microalbuminuria (92 +/- 11 micrograms/min, baseline versus 23 +/- 26 micrograms/min, 18 months; p < 0.05). No change in renal size was noted in the placebo group (15.4 +/- 0.8, baseline versus 14.9 +/- 0.7 cm, 18 months; NS) and albuminuria increased (118 +/- 15 micrograms/min, baseline versus 293 +/- 32 micrograms/min, 18 months; p < 0.05). Mean arterial pressure at 18 months was significantly lower in the lisinopril group compared to placebo (102 +/- 4, placebo versus 87 +/- 6 mm Hg, CEI, p < 0.05). This study supports previous animal studies that document reductions in both microalbuminuria and renal size by a CEI. The overall impact of these findings on preservation of renal function cannot be assessed, however, in this short-term study. Nephropathy is a common complication of sickle cell anemia and is often preceded by proteinurea. Our aim was to evaluate the effect of angiotensin-converting enzyme inhibition on microalbuminuria in sickle cell patients.
                We performed a randomized, double-blind, placebo-controlled trial in 22 normotensive patients with sickle cell anemia and persistent microalbuminuria. Patients received captopril (25 mg/day) or placebo and were followed up for 6 months. Albuminuria, blood pressure, and serum creatinine and hemoglobin concentrations were measured at baseline and at 1, 3, and 6 months. The primary outcome variable was the 6-month change in albuminuria between the two groups.
                Baseline albuminuria was 121 (SD 66) mg per 24 hours in the captopril group and 107 (SD 86) mg per 24 hours in the placebo group. Microalbuminuria decreased from baseline in the captopril group but increased in the placebo group. The mean absolute change and the mean percentage change in microalbuminuria were significantly different between the two groups at 6 months (absolute change -45 mg per 24 hours in the captopril group versus +18 mg per 24 hours in the placebo group, P <0.01; and percentage change -37% in the captopril group versus +17% in the placebo group, P <0.01). The 95% confidence intervals (CI) for the difference in albuminuria between the two groups were 63 (CI 40 to 86) mg per 24 hours for the mean absolute change and 54% (CI 22% to 85%) for the mean percentage change. Blood pressure decreased slightly from baseline in captopril-treated patients and did not change in the placebo group. The change was significantly different between the two groups only for diastolic blood pressure at 6 months (P <0.01).
                Captopril reduces albuminuria and slightly decreases blood pressure in patients with sickle cell anemia. More studies are required to demonstrate the sustained benefit on protein excretion. An imbalance between increased neutrophil elastase and a decreased antiprotease shield has been suggested as a factor contributing to the development of chronic lung disease (CLD). We hypothesized that administration of alpha1-proteinase inhibitor (A1PI), also known as alpha1-antitrypsin, to premature neonates would prevent CLD.
                A randomized, placebo-controlled, prospective study of A1PI supplementation was performed. Neonates <24 hours of age with birth weights 600-1000 g on respiratory support, and 1001-1250 g with respiratory distress syndrome (RDS) were eligible. Intravenous A1PI (60 mg/kg) or placebo was infused on days 0, 4, 7, and 14. Primary outcome was CLD in survivors, defined as the need for supplemental oxygen on day 28.
                A total of 106 patients were recruited. There were no significant differences between groups in birth weight or incidence of RDS. The incidence of CLD in survivors was lower in the treated group, but the difference did not reach statistical significance (relative risk [RR], 0.79; confidence interval [CI], 0.60-1.02). This beneficial trend persisted at 36 weeks corrected gestational age (RR, 0.48; CI, 0.23-1.00). The incidence of pulmonary hemorrhage was lower in the treated group (RR, 0.22; CI, 0.05-0.98). Other complications were not significantly different between groups.
                In this, the first trial of a protease inhibitor for the prevention of CLD in premature infants, the infusions were well-tolerated. A1PI therapy may impede the development of CLD and appears to reduce the incidence of pulmonary hemorrhage in some neonates born prematurely. Although the angiotensin receptor antagonist (ARB) shares the angiotensin-II-blocking activity with the angiotensin-converting enzyme inhibitor (ACE-I), pharmacological mechanisms of action of these agents differ. We evaluated the temporal profiles of action of ACE-I and ARB on urinary protein excretion and nitrate/nitrate (NO(x)) excretion in hypertensive (140 and/or 90 mmHg) patients with chronic renal disease (serum creatinine < 265 (range, 44-265) micromol/l or creatinine clearance > 30 (range, 30-121) ml/min). Patients with mild (<1 g/day; range, 0.4-1.0) and moderate proteinuria (>1 g/day; range, 1.1-6.9) were randomly assigned to ACE-I- and ARB-treated groups, and were treated with ACE-I (trandolapril or perindopril) or ARB(losartan or candesartan) for 48 weeks. In all groups, treatment with ACE-I or ARB decreased blood pressure to the same level, but had no effect on creatinine clearance. In patients with mild proteinuria, neither ACE-I nor ARB altered urinary protein excretion. In patients with moderate proteinuria, ACE-I caused 44 +/- 6% reduction in proteinuria (from 2.7 +/- 0.5 to 1.5 +/- 0.4 g/day, n = 14) at 12 weeks, and this beneficial effect persisted throughout the protocol (48 weeks, 1.2 +/- 0.2 g/day). In contrast, ARB did not produce a significant decrease in proteinuria at 12 weeks (23 +/- 8%, n = 13), but a 41 +/- 6% reduction in proteinuria was observed at 48 weeks. Similarly, although early (12 weeks) increases in urinary NO(x) excretion were observed with ACE-I (from 257 +/- 70 to 1111 +/- 160 micromol/day) and ARB (from 280 +/- 82 to 723 +/- 86 micromol/day), the ARB-induced increase in NO(x) excretion was smaller than that by ACE-I (P < 0.05). In conclusion, although both ACE-I and ARB reduce blood pressure similarly, the effect of these agents on proteinuria differs in chronic renal disease with moderate proteinuria. Relatively early onset of the proteinuria-reducing effect was observed with ACE-I, which paralleled the increase in urinary NO(x) excretion. Conversely, ARB decreased proteinuria and increased urinary NO(x) excretion gradually. These time course-dependent changes in proteinuria and urinary NO(x) may reflect the pharmacological property of ACE-I and ARB, with regard to the action on bradykinin.
There is not enough evidence to show that the administration of ACE inhibitors is associated with a reduction of microalbuminuria and proteinuria in people with sickle cell disease, although a potential for this was seen. More long-term studies involving multiple centers and larger cohorts using a randomized-controlled design are warranted, especially among the pediatric age group. Detailed reporting of each outcome measure is necessary to allow a clear cut interpretation in a systematic review. One of the difficulties encountered in this review was the lack of detailed data reported in the included study.