FOR THE RENAAL STUDY INVESTIGATORSOBJECTIVE -Metabolic factors such as glycemic control, hyperlipidemia, and hyperkalemia are important considerations in the treatment of patients with type 2 diabetes and nephropathy. In the RENAAL (Reduction of End Points in Type 2 Diabetes With the Angiotensin II Antagonist Losartan) study, losartan reduced renal outcomes in the patient population. This post hoc analysis of the RENAAL study reports the effects of losartan on selected metabolic parameters and assesses the relationship between baseline values of metabolic parameters and the primary composite end point or end-stage renal disease (ESRD).RESEARCH DESIGN AND METHODS -Glycemic control (HbA 1c ) and serum lipid, uric acid, and potassium levels were compared between the losartan and placebo groups over time, and baseline levels were correlated with the risk of reaching the primary composite end point (doubling of serum creatinine, ESRD, or death) or ESRD alone.RESULTS -Losartan did not adversely affect glycemic control or serum lipid levels. Losartan-treated patients had lower total (227.4 vs. 195.4 mg/dl) and LDL (142.2 vs. 111.7 mg/dl) cholesterol. Losartan was associated with a mean increase of up to 0.3 mEq/l in serum potassium levels; however, the rate of hyperkalemia-related discontinuation was similar between the placebo and losartan groups. Univariate analysis revealed that baseline total and LDL cholesterol and triglyceride levels were associated with increased risk of developing the primary composite end point. Similarly, total and LDL cholesterol were also associated with increased risk of developing ESRD.CONCLUSIONS -Overall, losartan was well tolerated by patients with type 2 diabetes and nephropathy and was associated with a favorable effect on the metabolic profile of this population.

OBJECTIVE -Asia is predicted to have the largest population of patients with diabetes who are at high risk for renal disease. In the Reduction of Endpoints in NIDDM with the Angiotensin II Antagonist Losartan (RENAAL) study, ϳ17% of patients were Asians. In this subgroup analysis, we examined the characteristics, response, and adherence to treatment of the Asian population, as well as their baseline predictors of risk of renal end points. RESEARCH DESIGN AND METHODS -A total of 252Asian patients were enrolled in the RENAAL study, which compared losartan (50 mg titrated to 100 mg) to placebo in addition to conventional antihypertensive medications in type 2 diabetic patients with nephropathy. Mean follow-up was 3.2 years. The effect of losartan therapy on renal and cardiovascular outcomes was examined, and baseline predictors of risk were determined using a Cox proportional hazards model with prespecified baseline covariates.RESULTS -Losartan reduced the risk of the primary composite end point composed of a doubling of serum creatinine, end-stage renal disease, or all-cause mortality in Asian patients by 35% (P ϭ 0.02). No difference between losartan and placebo was observed for the cardiovascular composite outcomes. Losartan reduced the level of proteinuria by 47% (P Ͻ 0.001) and rate of decrease in renal function by 31% (0.0074). Discontinuations were lower in the losartan-treated patients. The strongest baseline predictors of risk of renal end points were proteinuria (hazard ratio 1.42, P Ͻ 0.0001) and low Hb (0.81, P Ͻ 0.0001).CONCLUSIONS -In this subgroup analysis of the RENAAL study, losartan conferred significant renal benefits and was well tolerated in Asian patients with type 2 diabetes and clinical nephropathy. Baseline proteinuria and low Hb were strong predictors of risk of renal outcomes.

Losartan significantly reduced the risk of cardiorenal outcomes and was well tolerated by patients, including those with serum creatinine levels >or=2.0 g/dL. In addition, although this study shows that the reduction of proteinuria does not completely explain the impact of intervention on outcomes such as ESRD, reduction of proteinuria must remain an important consideration when treating patients with type 2 diabetes and nephropathy. However, the reduction of outcomes such as ESRD should remain the goal of therapy when evaluating renal protection in this patient population.

Aims/hypothesis: We explored the impact of baseline left ventricular hypertrophy (LVH) and losartan treatment on renal and cardiovascular (CV) events in 1,513

A key issue in the analysis of outcome trials is the adjustment for baseline covariates that influence the primary outcome. Imbalance of an important covariate between treatment groups at baseline is of considerable concern if one treatment group is favored over another with respect to the hypothesis testing outcome. With the use of the Reduction of Endpoints in NIDDM with the Angiotensin II Antagonist Losartan (RENAAL) study database as an example, the influence of baseline proteinuria on the primary composite endpoint, ESRD, and ESRD or death after adjusting for baseline proteinuria as a continuous covariate was examined. Increasing baseline proteinuria was associated with increased risk for renal events, confirming that proteinuria is an important covariate for renal outcomes. When the randomization was stratified according proteinuria <2000 mg/g or >2000 mg/g, within the higher proteinuria stratum (>2000 mg/g), patients in the losartan group had a higher baseline mean proteinuria value. When the imbalance was adjusted, an increase in the magnitude and the significance of the risk reduction with losartan for each outcome was observed. No apparent interaction between treatment effect and baseline proteinuria was found, and there was no heterogeneity in the treatment response in patients with different baseline proteinuria levels. After proteinuria was adjusted as a continuous variable, greater treatment effects were observed in the RENAAL study. This effect was due solely to the imbalance in baseline proteinuria. Considering the importance of proteinuria as a risk factor, adjustment for baseline proteinuria as a continuous covariate should be prespecified in the design and analysis of clinical trials involving renal outcomes, even when patients are stratified on the basis of level of proteinuria.