Purpose: We examined the effect of the angiotensin II receptor antagonist (ARB), irbesartan (Irb), on urinary markers in hypertensive patients.
Subjects and methods: We evaluated 87 patients in a 12-month prospective study: Group 1) 33 patients who were newly administered Irb (100 mg); Group 2) 33 patients who were switched to Irb ; and Group 3) 21 patients who did not undergo change to pre-existing Irb administration. Height, weight, systolic and diastolic blood pressure, clinical parameters, urine protein : creatinine ratio (UPC), and urinary markers (liver-type fatty acid binding protein (L-FABP), N-acetyl-β-d-glucosaminidase, α1-microglobulin, and β2-microglobulin) were measured at the baseline and at 12, 24, and 48 weeks. We examined changes in the clinical parameters, UPC, and urinary markers from the baseline.
Results: A tendency toward hypotension was observed in all groups (group newly administered Irb, group switched to Irb, and group without changes to Irb), but the difference was not statistically significant. Urinary L-FABP concentration (μg/g x Cr) decreased from 13.2 --> 8.9 and13.2 --> 10.2 at 24 and 48 weeks, respectively, after administration (p < 0.01) in the group newly administered Irb, from 19.5 --> 10.1 at 48 weeks after administration (p < 0.01) in the switched group, and from 9.6 --> 8.3, 8.1, and 6.2 (p < 0.01) in the group without changes to Irb. Changes in the Irb-administered groups were readily apparent. UPC decreased in the Irb-administered groups (p < 0.05), but there were no significant differences in the other urinary markers. Changes in urinary L-FABP and UPC were positively correlated in all cases of the Irb-administered groups (r = 0.25-0.57, p < 0.05), but were not positively correlated in the group without changes to Irb administration. The change in UPC was positively correlated with changes in systolic and diastolic blood pressure in all cases (r = 0.23-0.57, p < 0.05).
Conclusion: It was concluded that the urinary L-FABP level, blood pressure, and UPC of hypertensive patients should be managed in daily practice using an ARB, including Irb.