Diabetes Care. 2003 Mar;26(3):569-74. Comparative effects of Irbesartan on ambulatory and office blood pressure: a substudy of ambulatory blood pressure from the Irbesartan in Patients with Type 2 Diabetes and Microalbuminuria study. (IRMA2) Rossing K， Christensen PK， Andersen S， Hovind P， Hansen HP， Parving HH; Irbesartan in Patients with Type 2 Diabetes and Microalbuminuria Study. Steno Diabetes Center， Niels Steensens Vej 2， 2820 Gentofte， Denmark. krossing@dadlnet.dk
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) micro g/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.