title: Associations between Omega-3 Index increase and triacylglyceride decrease in subjects with hypertriglyceridemia in response to six month of EPA and DHA supplementation.
abstract: BACKGROUND
  Ingestion of long-chain n-3 PUFA effectively decreases serum triacylglycerol (TAG) levels and increases the Omega-3 Index, defined as the % of EPA and DHA in erythrocyte fatty acids. However, it remains unclear whether there is a relationship between the Omega-3 Index increase (ΔO3I increase) and the TAG level decrease (ΔTAG). We hypothesized that TAG reduction is strongly depended on Omega-3 Index increase.
  
  
  METHODS
  Secondary analyses of data from a former double-blind placebo-controlled trial in which 150 dyslipidemic statin-treated subjects were randomized to four capsules of fish oil daily either as re-esterified TAG or ethyl esters in identical doses (1.01 g EPA+0.67 g DHA) or corn oil as a placebo for a period of six month.
  
  
  RESULTS
  108 subjects fulfilled the criteria of the current study protocol and were included in the analyses. A weak but significant negative correlation between ΔO3I and ΔTAG was observed (r=-0.211, p<0.05). However, the relation between ΔO3I and serum ΔTAG was not linear (coefficients of determination R(2): 0.044). After sub-grouping the study population into Omega-3 Index response groups, the group with a mean ΔO3I of>4% after six months of n-3 PUFA treatment demonstrated the greatest TAG reduction.
  
  
  CONCLUSIONS
  A weak association between Omega-3 Index increase and TAG level decrease was found. This may be explained by highly fluctuating TAG levels, a large inter-individual difference in response of the Omega-3 Index, a cohort of subjects with only slightly elevated TAG levels and high Omega-3 Index values at baseline, and possibly to insufficient statistical power. Since there was no strong association between Omega-3 Index increase and the TAG level decrease, we conclude that changes in serum TAG levels are not a viable substitute for the Omega-3 Index to monitor treatment with EPA and DHA.
authors.affiliation: Institute of Food Science and Human Nutrition, Leibniz University Hannover, Germany. Electronic address: schuchardt@nutrition.uni-hannover.de.
authors.forename: Jan Philipp
authors.initials: JP
authors.lastname: Schuchardt
authors.affiliation: Institute of Food Science and Human Nutrition, Leibniz University Hannover, Germany.
authors.forename: Juliane
authors.initials: J
authors.lastname: Neubronner
authors.affiliation: Department of Public Health Sciences and the Cardiology Division, Department of Medicine, the University of Rochester School of Medicine and Dentistry, Rochester, New York, USA.
authors.forename: Robert C
authors.initials: RC
authors.lastname: Block
authors.affiliation: PreventiveCardiology, Medizinische Klinik und Poliklinik Innenstadt, Ludwig Maximilians University Munich, Germany.
authors.forename: Clemens
authors.initials: C
authors.lastname: von Schacky
authors.affiliation: Institute of Food Science and Human Nutrition, Leibniz University Hannover, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Hahn
mesh_terms: D000368:Aged; D019587:Dietary Supplements; D004281:Docosahexaenoic Acids / Q000627:therapeutic use*; D004311:Double-Blind Method; D015118:Eicosapentaenoic Acid / Q000627:therapeutic use*; D015525:Fatty Acids, Omega-3 / Q000097:blood*; D005260:Female; D006801:Humans; D015228:Hypertriglyceridemia / Q000097:blood* / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D014280:Triglycerides / Q000097:blood*
chemical_list: D015525:Fatty Acids, Omega-3; D014280:Triglycerides; D004281:Docosahexaenoic Acids; D015118:Eicosapentaenoic Acid
keywords: Hypertriglyceridemia; Omega-3 Index; Triacylglycerides