Omega-3 fatty acid supplementation increases 1,25-dihydroxyvitamin D and fetuin-A levels in dialysis patients

• Published in: Nutrition research (New York, N.Y.) Vol. 32; no. 7; pp. 495 - 502
• Main Authors: An, Won Suk, Lee, Su Mi, Son, Young Ki, Kim, Seong Eun, Kim, Ki Hyun, Han, Jin Yeong, Bae, Hae Rahn, Rha, Seo Hee, Park, Yongsoon
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.07.2012; Elsevier
• Subjects: 1,25-dihydroxyvitamin D; Adult; Aged; Aged, 80 and over; alpha-2-HS-Glycoprotein - analysis; Biological and medical sciences; Calcium - blood; Cardiovascular Diseases - drug therapy; Cardiovascular Diseases - physiopathology; Dialysis; Diet; Dietary Supplements; Docosahexaenoic Acids - administration & dosage; Drug Combinations; Eicosapentaenoic Acid - administration & dosage; Energy Intake; Erythrocyte Membrane - drug effects; Erythrocyte Membrane - metabolism; Fatty Acids, Omega-3 - administration & dosage; Fatty Acids, Omega-3 - blood; Feeding. Feeding behavior; Female; Fetuin-A; Fibroblast growth factor 23; Fundamental and applied biological sciences. Psychology; Gastroenterology and Hepatology; Human; Humans; Male; Middle Aged; Oleic Acid - blood; Omega-3 fatty acid; Parathyroid Hormone - blood; Peritoneal Dialysis; Phosphorus - blood; Radioimmunoassay; Renal Dialysis; Vascular Calcification - drug therapy; Vascular Calcification - physiopathology; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Vitamin D - administration & dosage; Vitamin D - analogs & derivatives; Vitamin D - blood; CRP; Fetuin-A; C-reactive protein; PTH; fibroblast growth factor 23; vascular calcification; fatty acid; 1,25(OH)2D; blood urea nitrogen; 1,25-dihydroxyvitamin D; FGF-23; docosahexaenoic acid; 25(OH)D; Fractional clearance of urea as a function of its distribution volume; BUN; Kt/V urea; BMI; AA; arachidonic acid; Human; cardiovascular disease; parathyroid hormone; 25-hydroxyvitamin D; body mass index; VC; CVD; eicosapentaenoic acid; PD; EPA; Omega-3 fatty acid; hemodialysis; peritoneal dialysis; Dialysis; FA; DHA; HD; Fibroblast growth factor 23; Fibroblast growth factor; Lipids; n-3 fatty acid; Vertebrata; Mammalia; Unsaturated fatty acid; Supplementation
• ISSN: 0271-5317; 1879-0739
• DOI: 10.1016/j.nutres.2012.06.005

Abstract Vitamin D deficiency, low levels of fetuin-A, and fibroblast growth factor 23 (FGF-23) are related to vascular calcification, which is associated with cardiovascular disease. We hypothesized that omega-3 fatty acid (FA), which has cardioprotective properties, modifies vitamin D status, fetuin-A, and FGF-23 levels in dialysis patients. In a randomized, open-label, controlled study, a total of 47 patients treated with dialysis for at least 1 year were randomized to treatment for 6 months with omega-3 FAs (Omacor, 3 g/d; Pronova, Sandefjord, Norway) or a control group. Levels of fetuin-A and FGF-23 were measured by enzyme-linked immunoassay, 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D were measured by radioimmunoassay. The mean age of the enrolled patients was 57.4 ± 10.4 years, and mean dialysis duration was 46.5 ± 28.1 months. Twenty-seven hemodialysis patients and 16 peritoneal dialysis patients finished this trial. After 6 months, the levels of 1,25-dihydroxyvitamin D and fetuin-A were significantly increased in the group taking the omega-3 FA supplement compared with baseline. Levels of calcium, phosphorous, parathyroid hormone, 25-hydroxyvitamin D, FGF-23, and lipid profiles were not significantly changed in the omega-3 FA–supplemented group after 6 months compared with baseline. The erythrocyte membrane contents of eicosapentaenoic acid and docosahexaenoic acid were significantly increased, and oleic acid content was significantly decreased in the omega-3 FA–supplemented group after 6 months compared with baseline. Regarding vascular calcification and cardiovascular disease, omega-3 FA supplementation may have a clinical benefit caused by activating vitamin D, increasing fetuin-A levels, and modifying erythrocyte membrane FA contents in dialysis patients.