We read with great interest the recent article by de Leeuw and colleagues.1 Their Intervention as a Goal in Hypertension Treatment (INSIGHT) trial is the landmark study to compare cardiovascular outcomes of 2 classes of antihypertensive agents: nifedipine and the hydrochlorothiazide–amiloride hydrochloride combination. In the post hoc analysis, they concluded that renal function was better preserved with therapy with a calcium channel blocker than with diuretics.1 However, the reduction in glomerular filtration rate (GFR) with diuretic treatment is functional and therefore may be favorable for renoprotection, as recognized by inhibitors of the renin-angiotensin system.