title: Variation in fasting and non-fasting serum enterolactone concentrations in women of the Malmö Diet and Cancer cohort.
abstract: OBJECTIVE
  The aim of this study was to examine the variation of enterolactone from fasting and non-fasting blood of middle-aged healthy women eating a normal diet to determine the usefulness of a single sample in epidemiological studies.
  
  
  METHODS
  Twenty-six women born between 1940 and 1950 were recruited within the Malmö Diet and Cancer cohort. Three non-fasting and two overnight fasting samples were collected from each individual during a 5-week period. Twenty-one participated in all measurements. Enterolactone concentrations were analyzed by time-resolved fluoroimmunoassay.
  
  
  RESULTS
  The within-subject and between-subject variations (coefficient of variations, CV) were estimated to 59 and 89% respectively for fasting samples and 71 and 67% for non-fasting samples. The intraclass correlation coefficients (ICC) were estimated to 0.66 (95% confidence interval (CI) 0.35-0.84) for fasting and 0.48 (95% CI, 0.22-0.72) for non-fasting samples.
  
  
  CONCLUSIONS
  Although the estimated ICC for blood samples was moderate, it indicates that enterolactone levels of both fasting and non-fasting blood samples should be useful in future projects within the Malmö Diet and Cancer cohort.
authors.affiliation: Department of Clinical Sciences, Lund University, Malmö, Sweden.
authors.forename: E
authors.initials: E
authors.lastname: Sonestedt
authors.forename: U
authors.initials: U
authors.lastname: Ericson
authors.forename: B
authors.initials: B
authors.lastname: Gullberg
authors.forename: J L
authors.initials: JL
authors.lastname: Peñalvo
authors.forename: H
authors.initials: H
authors.lastname: Adlercreutz
authors.forename: E
authors.initials: E
authors.lastname: Wirfält
mesh_terms: D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000032:analysis / Q000097:blood; D015415:Biomarkers / Q000097:blood; D015331:Cohort Studies; D004032:Diet; D005215:Fasting / Q000097:blood*; D005260:Female; D015200:Fluoroimmunoassay / Q000379:methods; D006801:Humans; D017705:Lignans / Q000008:administration & dosage* / Q000032:analysis / Q000097:blood* / Q000378:metabolism; D008875:Middle Aged; D048789:Phytoestrogens / Q000032:analysis / Q000097:blood*; D019518:Postprandial Period / Q000502:physiology*; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors
chemical_list: D015415:Biomarkers; D017705:Lignans; D048789:Phytoestrogens; D015107:4-Butyrolactone; C029497:2,3-bis(3'-hydroxybenzyl)butyrolactone