title: Red blood cell fatty acid analysis for determining compliance with omega3 supplements in dry eye disease trials.
abstract: OBJECTIVE
  To evaluate pill counts and red blood cell (RBC) membrane fatty acid profiles as measures of compliance with oral omega3 polyunsaturated fatty acids (ω3 PUFAs) and to compare the two techniques.
  
  
  METHODS
  Sixteen dry eye disease subjects were given oral ω3 PUFA or placebo for 3 months. Compliance was measured by pill counts and blood tests at baseline and 3 months. The Wilcoxon signed-rank tests and rank-sum tests were used to compare changes from baseline and the difference between the two groups; Spearman correlation coefficients were used to assess the relationship of pill counts to changes in blood FAs.
  
  
  RESULTS
  Pill counts for the ω3 (n=7) and placebo (n=9) groups showed a mean consumption of 4.39 and 4.76 pills per day, respectively. In the ω3 group, the median change from baseline was +1.46% for eicosapentaenoic acid (EPA) (P=0.03), +1.49% for docosahexaenoic acid (DHA) (P=0.08), and -1.91% for arachidonic acids (AA) (P=0.02). In the placebo group, median changes in all measured FAs were small and not statistically significant. The difference in change in FA levels between the two groups was significantly greater for EPA (P=0.01) and AA (P=0.04). The correlations between pill counts and changes in EPA (r=0.36, P=0.43) and DHA (r=0.17, P=0.70) were not strong.
  
  
  CONCLUSIONS
  RBC FA analysis can be used to measure compliance in the active group and also monitor the placebo group for nonstudy ω3 intake. Low correlation of pill counts with blood levels suggests that pill counts alone may be inaccurate and should be replaced or supplemented with objective measures.
authors: 1 Department of Ophthalmology, Mount Sinai School of Medicine , Mount Sinai Medical Center, New York, New York.
authors: Neha
authors: N
authors: Gadaria-Rathod
authors: Peter G
authors: PG
authors: Dentone
authors: Ellen
authors: E
authors: Peskin
authors: Maureen G
authors: MG
authors: Maguire
authors: Ann
authors: A
authors: Moser
authors: Penny A
authors: PA
authors: Asbell
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000368:Aged; D001095:Arachidonic Acids / Q000008:administration & dosage / Q000097:blood; D019587:Dietary Supplements; D004281:Docosahexaenoic Acids / Q000008:administration & dosage / Q000097:blood; D004311:Double-Blind Method; D015352:Dry Eye Syndromes / Q000188:drug therapy*; D015118:Eicosapentaenoic Acid / Q000008:administration & dosage / Q000097:blood; D004910:Erythrocyte Membrane / Q000378:metabolism; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage* / Q000097:blood; D005240:Feasibility Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D055118:Medication Adherence; D008875:Middle Aged; D018709:Statistics, Nonparametric
chemical_list: D001095:Arachidonic Acids; D015525:Fatty Acids, Omega-3; D004281:Docosahexaenoic Acids; D015118:Eicosapentaenoic Acid
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