Objective: The RED LEVEL study (REnal Disease: LErcanidipine Valuable Effect on urine protein Losses) directly compares, in an explorative fashion, the effects of lercanidipine + enalapril and amlodipine + enalapril combinations on renal parameters in hypertensive subjects.

Research design and methods: This was a 1 year, prospective, multi-center, randomized, open-label, blinded-endpoint (PROBE) study in hypertensive patients with albuminuria.

Main outcome measures: Renal function (albuminuria, serum creatinine, creatinine clearance, estimated glomerular filtration rate and proteinuria); blood pressure.

Results: Albuminuria was significantly reduced, compared with baseline values, with the lercanidipine + enalapril combination over the entire study period; at month 3, month 6 and month 12, changes from baseline were: −162.5 (p-value = 0.0439), −425.8 (p-value = 0.0010), −329.0 (p-value = 0.0011) mg/24 h), respectively. On the other hand, this improvement was not observed with enalapril + amlodipine. Other parameters of renal function such as serum creatinine, creatinine clearance, estimated glomerular filtration rate and proteinuria did not change over the study. Both lercanidipine + enalapril and amlodipine + enalapril significantly reduced systolic and diastolic blood pressure values from baseline all over the study period with no significant differences between groups. Safety outcomes were comparable between the two groups.

Conclusions: Overall, the results of this explorative study lend support to the anti-albuminuric effect of the lercanidipine + enalapril combination and to the long term renal-protective effects of this combination in patients with hypertension.