Vitamin E therapy in IgA nephropathy: a double-blind, placebo-controlled study.
IgA nephropathy is the world's most common primary glomerulonephropathy. Recent evidence in a rat model implicated excessive production of oxygen-free radicals in the pathogenesis and suggested that vitamin E-treatment ameliorated progression. We studied this antioxidant therapy on the glomerular filtration rate (GFR), proteinuria and hematuria in biopsy-proven IgA nephropathy in children. The duration of treatment or placebo was 2 years, with vitamin E treatment consisting of 400 IU/day in children weighing <30 kg, and twice that dose for those >30 kg. We measured GFR at entry, midpoint and exit. At baseline and at 4-month intervals after randomization, urinary protein/creatinine ratios and urinalysis were examined. The mixed model procedure with log transformation was used in data analysis to test treatment difference as well as the potential time effect. Fifty-five patients were randomized and 38 completed at least 1 year of follow-up. At entry, the clinical characteristics were not different between the treatment and placebo groups. There was a trend toward better preservation of GFR in vitamin E-treated versus placebo patients, 127+/-50 vs. 112+/-31 ml/min/1.73 m(2), respectively ( P=0.09). The urinary protein/creatinine ratio was significantly lower in the vitamin E-treated group vs. placebo; 0.24+/-0.38 vs. 0.61+/-1.37 ( P<0.013). However, there was no difference in the prevalence of hematuria between the groups. Vitamin E treatment in our study patients was associated with significantly lower proteinuria, but no effect on hematuria. While there was a trend toward stabilization of GFR in the vitamin E-treated patients, long-term treatment and follow-up are needed to determine whether antioxidant therapy is associated with preservation of renal function in IgA nephropathy.
Chan
James C M
JC
Virginia Commonwealth University, Richmond, Virginia, USA. chanj@mmc.org
Mahan
John D
JD
Trachtman
Howard
H
Scheinman
Jon
J
Flynn
Joseph T
JT
Alon
Uri S
US
Lande
Marc B
MB
Weiss
Robert A
RA
Norkus
Edward P
EP
D000293:Adolescent; D000975:Antioxidants / Q000008:administration & dosage*; D002648:Child; D004311:Double-Blind Method; D005260:Female; D005919:Glomerular Filtration Rate / Q000187:drug effects; D005922:Glomerulonephritis, IGA / Q000188:drug therapy*; D006801:Humans; D008297:Male; D010865:Pilot Projects; D010919:Placebos; D011446:Prospective Studies; D011507:Proteinuria / Q000188:drug therapy; D016896:Treatment Outcome; D014810:Vitamin E / Q000008:administration & dosage*
D000975:Antioxidants; D010919:Placebos; D014810:Vitamin E