Table 2.

Effects of uric acid lowering on renal and systemic renin-angiotensin system

Parameter	Probenecid (n=40)				Allopurinol (n=35)				Placebo (n=45)				Probenecid Versus Placebo Pb	Allopurinol Versus Placebo Pb	Treatment Effect Pc
	Baseline	8-Wk	Change from Baseline	Pa	Baseline	8-Wk	Change from Baseline	Pa	Baseline	8-Wk	Change from Baseline	Pa
Precaptopril RPF
No. of participants	40	40			35	34			45	45
Median (IQR), ml/min per 1.73 m2	480 (421–568)	474 (428–556)	−3 (−27 to 19)	0.40	489 (409–550)	467 (404–540)	5 (−10 to 28)	0.28	534 (457–571)	505 (456–547)	−4 (−35 to 10)	0.29	0.81	0.12	0.25
Postcaptopril RPF
No. of participants	40	40			35	34			45	45
Median (IQR), ml/min per 1.73 m2	531 (447–643)	503 (464–608)	−6 (−31 to 36)	0.73	517 (442–567)	495 (44–571)	5 (−30 to 28)	0.97	544 (480–613)	535 (476–593)	−11 (−30 to 19)	0.18	0.54	0.34	0.63
Change in RPF
No. of participants	40	40			35	34			45	45
Median (IQR), ml/min per 1.73 m2	38 (14–67)	33 (12–72)	−4 (−24 to 32)	0.83	41 (16–65)	36 (17–55)	−4 (−16 to 9)	0.32	30 (7–44)	30 (−1 to 48)	1 (−21 to 17)	0.96	0.77	0.58	0.77
PRA
No. of participants	39	40			35	33			43	44
Median (IQR), ng/ml per h	0.3 (0.1–0.6)	0.4 (0.2–0.7)	0.1 (−0.2 to 0.4)	0.13	0.3 (0.1–0.5)	0.3 (0.2–0.5)	0.0 (−0.2 to 0.2)	0.54	0.2 (0.1–0.4)	0.2 (0.1–0.6)	0.1 (−0.1 to 0.2)	0.13	0.60	0.74	0.81
Ang II
No. of participants	40	39			34	34			45	45
Median (IQR), pg/ml	18.8 (15.3–22.3)	20.3 (18.5–22.7)	1.7 (0.3.0–4.7)	0.18	19.1 (17.0–23.3)	21.4 (18.2–24.4)	1.6 (−1.6 to 5.1)	0.04	19.0 (16.4–20.9)	19.1 (17.0–21.5)	−0.8 (−2.2 to 3.3)	0.93	0.28	0.14	0.30

RPF, renal plasma flow; IQR, interquartile range; PRA, plasma renin activity; AngII, angiotensin II.

^aP value from the Wilcoxon signed rank test of change in parameter within an individual from baseline to 8 wk.

^bP value from the Kruskal–Wallis test of change in parameter between baseline and 8 wk within individuals across treatment groups.