Effect of 12-month therapy with omega-3 polyunsaturated acids on glomerular filtration response to dopamine in IgA nephropathy.
BACKGROUND
Omega-3 polyunsaturated acids therapy is efficient in primary IgA nephropathy. It is unknown whether doses of omega-3 smaller than those given previously are still effective. The aim of the study was to examine the effect of omega-3 therapy on renal vascular function in relation to proteinuria and urinary excretion of N-acetyl-beta-D-glucosaminidase (NAG).


METHODS
20 IgA patients aged 36.5 +/- 10.77 with creatinine clearance (Cr(cl)) 105.71 +/- 27.3 ml/min and proteinuria 3.31 +/- 2.01 g/24 h were given orally 810 mg EPA and 540 mg DHA daily for 12 months. Before and at the end of the study, 24-hour proteinuria, serum homocysteine, and Cr(cl) were measured. At the same time, renal vascular function was estimated as dopamine-induced glomerular filtration response (DIR). DIR was measured as: two 120-min lasting Cr(cl) (before and during 2 microg/kg b.w./min i.v. dopamine).


RESULTS
The results obtained during follow-up were as follows (baseline vs. after therapy): DIR 14.9 +/- 16.4 vs. 30.3 +/- 14.3% (p < 0.01); urine protein 2.31 +/- 2.01 vs. 1.31 +/- 1.37 g/24 h (p < 0.01); (Cr(cl)) 105.71 +/- 27.3 vs. 103.9 +/- 20.9 ml/min (n.s.); NAG 8.3 +/- 1.8 vs. 6.0 +/- 1.2 U/g(creat) (p < 0.01), and homocysteine 16.2 +/- 3.15 vs. 13.8 +/- 2.6 micromol/l (p < 0.05). The only correlation found was linear correlation between basal DIR and DIR change (r = -0.570; p < 0.010) and basal NAG (r = -0.460; p < 0.50).


CONCLUSIONS
Omega-3 supplementation is associated with the improvement of both renal vascular function and tubule function.
Sulikowska
Beata
B
Department of Transplantation, Nephrology and Internal Medicine, Medical University of Gdańsk, Gdańsk, Poland.
Niewegłowski
Tomasz
T
Manitius
Jacek
J
Lysiak-Szydłowska
Wiesława
W
Rutkowski
Bolesław
B
D000293:Adolescent; D000328:Adult; D004298:Dopamine; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage* / Q000494:pharmacology; D005260:Female; D005919:Glomerular Filtration Rate / Q000187:drug effects*; D005922:Glomerulonephritis, IGA / Q000188:drug therapy* / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013997:Time Factors
D015525:Fatty Acids, Omega-3; D004298:Dopamine