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Renoprotection with and without blood pressure reduction. AT1-receptor blockade dose dependently lowers blood pressure (BP) and albuminuria. Reduction of BP and albuminuria are independent treatment targets for renoprotection, but whether this requires similar dose titration is unknown. We tested this in two studies designed to find the optimal antialbuminuric dose of losartan in type 1 diabetic (DM, N = 50) and nondiabetic renal patients (ND, N = 12). After baseline, treatment followed with losartan 50, 100, and 150 mg/day, each dose for eight (DM) or six weeks (ND). At the end of each period, albuminuria (24-hour samples) and mean arterial pressure (MAP) were measured. Patients were divided into "good" and "poor" BP responders (BP+, BP-) according to BP response above or below group median. Baseline MAP in the BP- groups was 102 (97, 104) mm Hg in DM (median, 95% CI) and 91 (80, 108) mm Hg in ND. The top of the dose response for BP (obtained at losartan 100 mg) in the BP- groups was -2 (-4, 3) mm Hg in DM and –1 (-6, 2) mm Hg in ND, versus -15 (-18, -12) mm Hg and -16 (-26, -18) mm Hg in BP+ groups (both P < 0.05). Albuminuria was reduced dose dependently both in BP- and BP+: with 100 mg, the reduction in albuminuria in DM BP- was -32% (-49, 13) versus -45% (-60, -38) in DM BP+ and -45% (-70,-7) versus –25% (-58, -6) in ND BP- and BP+ (all P > 0.05). Moreover, in patients in whom BP fell below the recommended treatment target of 130/80 mm Hg (13 in DM and 10 in ND), albuminuria was progressively reduced, with further increasing the dose of losartan in most patients. Absence of BP response to losartan does not preclude a reduction in albuminuria, and optimal reduction of albuminuria may require titration beyond the predefined BP target. [ABSTRACT FROM AUTHOR]

OBJECTIVE -- Irbesartan was renoprotective independently of its blood pressure-lowering effect in the Irbesartan in Patients With Type 2 Diabetes and Microalbuminuria (IRMA2) study. However, blood pressure was evaluated by trough office blood pressure (OBP), which may underestimate reductions in 24-h ambulatory blood pressure (ABP). In the present study, we evaluated 24-h blood pressure patterns in a subpopulation of the IRMA2 trial. RESEARCH DESIGN AND METHODS -- Type 2 diabetic patients (n = 43) with persistent microalbuminuria (as determined by repeated overnight measurements of urinary albumin excretion [UAE]) and hypertension who were included in the IRMA2 study at the Steno Diabetes Center were subjected to 24-h ABP (Takeda, TM2420) measurements before and 2 years after randomization to placebo (n = 15), irbesartan 150 mg daily (Irb150; n = 13), or irbesartan 300 mg daily (Irb300; n = 15). RESULTS -- At baseline, the placebo, Irb150, and Irb300 groups were comparable: OBP: 157 ± 15/89 ± 7, 156 ± 15/91 = 11, and 159 ± 16/90 ± 9 mmHg (NS); 24-h ABP: 148 ± 13/83 ± 11, 148 ± 16/82 ± 7 and 147 ± 16/81 ± 10 mmHg (NS); and UAE (geometric mean with 95% CI): 43 (32-57), 46 (30-70), and 59 (42-85) µg/min (NS), respectively. We found that 2 years after randomization, OBP was significantly reduced in all three groups (by 11/7, 13/8, and 13/8 mmHg in the placebo, Irb150, and Irb300 groups, respectively), but that there were no significant differences among groups. Reductions in 24-h ABP were similar in the three groups (11/10, 5/7, and 7/8 mmHg, respectively; NS), as were reductions in day ABP (11/9, 7/7, and 8/9 mmHg, respectively; NS) and night ABP (4/11, 7/7, and 3/3 mmHg, respectively; NS). The reduction in UAE at the end of the study was 0% (-86 to 42), 38% (- 14 to 66), and 73% (59 to 82), respectively (overall, P < 0.01). CONCLUSION -- Irbesartan is renoprotective independently of its beneficial effect in lowering 24-h blood pressure in patients with type 2 diabetes and persistent microalbuminuria. [ABSTRACT FROM AUTHOR]