Résumé : Background: An open-label, randomized, multinational, parallel-group trial compared the short-term (6-week) renal effects of rosuvastatin 40 mg and simvastatin 80 mg in patients with hypercholesterolemia. Most patients (93%) then entered an optional open-label extension (OLE) to assess long-term (up to 72 weeks) renal effects of rosuvastatin. Methods: After dietary lead-in, 626 patients were randomized to rosuvastatin or simvastatin for 6 weeks, followed by an optional, single-arm OLE to assess longer-term effects of rosuvastatin on renal function, safety, and efficacy. Results: The primary endpoint, a shift in urine dipstick protein from "none" or "trace" at baseline to "+" or greater in the first 4 weeks, was observed in 6.4% of patients receiving rosuvastatin and 1.0% of those receiving simvastatin. The incidence of shifts in urine dipstick protein at any time from none or trace to "++" or greater (proteinuria), was low (1.3%, rosuvastatin; 0.3%, simvastatin), transient and urine protein was predominantly of tubular or mixed origin. More patients achieved Third Adult Treatment Panel of the National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (NCEP ATP III) low-density lipoprotein cholesterol (LDL-C) goals with rosuvastatin vs simvastatin after 6 weeks (77.9% vs 60.4%). Results from the OLE (median rosuvastatin treatment = 47 weeks) were consistent with the randomized period. Mean serum creatinine levels remained stable, indicating no decline in renal function. Conclusion: A small proportion of patients treated with rosuvastatin 40 mg may experience a transient proteinuria, predominantly of tubular origin and not associated with declining renal function. Rosuvastatin modified lipid levels effectively, enabled more patients to attain LDL-C goals, and demonstrated a favorable benefit/risk profile. © 2007 National Lipid Association.