Is Body Size a Biomarker for Optimizing Dosing of Omega-3 Polyunsaturated Fatty Acids in the Treatment of Patients with IgA Nephropathy?

• Published in: Clinical journal of the American Society of Nephrology 2006-09, Vol.1 (5), p.933-939
• Main Authors: Donadio, James V, Bergstralh, Eric J, Bibus, Douglas M, Grande, Joseph P
• Format: Article
• Language: English
• Subjects: Arachidonic Acid - blood; Body Mass Index; Body Size; Body Weight; Creatinine - blood; Disease Progression; Docosahexaenoic Acids - administration & dosage; Docosahexaenoic Acids - blood; Dose-Response Relationship, Drug; Drug Combinations; Eicosapentaenoic Acid - administration & dosage; Eicosapentaenoic Acid - blood; Glomerulonephritis, IGA - blood; Glomerulonephritis, IGA - complications; Glomerulonephritis, IGA - drug therapy; Glomerulonephritis, IGA - physiopathology; Humans; Kaplan-Meier Estimate; Kidney Failure, Chronic - blood; Kidney Failure, Chronic - etiology; Kidney Failure, Chronic - physiopathology; Phospholipids - blood; Proportional Hazards Models; Proteinuria - blood; Proteinuria - drug therapy; Proteinuria - etiology; Proteinuria - physiopathology; Risk Assessment; Time Factors; Treatment Outcome
• ISSN: 1555-9041; 1555-905X
• DOI: 10.2215/CJN.00260106

Re-analysis of the North American IgA Nephropathy Study suggested that efficacy of omega-3 polyunsaturated fatty acids (omega-3 PUFA) was dosage-dependent on the basis of body size and plasma omega-3/omega-6 and eicosapentaenoic acid (EPA)/arachidonic acid (AA) ratios. The objective of this study was to confirm these assertions. Data from a previously reported randomized 2-yr clinical trial in which two dosages of an ethyl ester omega-3 PUFA (Omacor) were given to 73 high-risk patients with IgA nephropathy were reviewed. Omacor also was used in the North American IgA Nephropathy Study. Parameters included body weight; body mass index (BMI); plasma phospholipid AA, EPA, and docosahexanoic acid (DHA) levels and serum creatinine and 24-h urine protein (UP) levels during the 2-yr trial; and time to ESRD after 6.4 yr. Plasma phospholipid levels of EPA, DHA, and EPA/AA ratios were significantly inversely correlated with increasing body weight and BMI in the Omacor 4-g dosage group but not in the Omacor 8-g dosage group. Conversely, increasing levels of lipid parameters were observed with increasing dosages of Omacor (EPA+DHA) in grams per kilogram of body weight at 6 wk of treatment. None of the plasma omega-3 PUFA levels, EPA/AA ratios, or Omacor dosage per kilogram was significantly associated with reciprocal serum creatinine or UP slopes during the 2-yr trial or with ESRD. This post hoc analysis of body weight and BMI, plasma omega-3 PUFA status, and renal outcome did not find that treatment efficacy of omega-3 PUFA was dosage dependent on the basis of body size.