title: Fasting increases serum bilirubin levels in clinically normal, healthy males but not females: a retrospective study from phase I clinical trial participants.
abstract: OBJECTIVE
  To examine if fasting affects serum bilirubin levels in clinically healthy males and females.
  
  
  METHODS
  We used retrospective data from phase I clinical trials where blood was collected in either a fed or fasting state at screening and predosing time points and analysed for total bilirubin levels as per standard clinical procedures. Participants were clinically healthy males (n=105) or females (n=30) aged 18-48 inclusive who participated in a phase I clinical trial in 2012 or 2013.
  
  
  RESULTS
  We found a statistically significant increase in total serum bilirubin levels in fasting males as compared with non-fasting males. The fasting time correlated positively with increased bilirubin levels. The age of the healthy males did not correlate with their fasting bilirubin level. We found no correlation between fasting and bilirubin levels in clinically normal females.
  
  
  CONCLUSIONS
  The recruitment and screening of volunteers for a clinical trial is a time-consuming and expensive process. This study clearly demonstrates that testing for serum bilirubin should be conducted on non-fasting male subjects. If fasting is required, then participants should not be excluded from a trial based on an elevated serum bilirubin that is deemed non-clinically significant.
authors.affiliation: Q-Pharm Pty Limited, Brisbane, Queensland, Australia The QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia School of Medicine, The University of Queensland, Brisbane, Queensland, Australia Mater Hospital and Mater Medical Research Institute, Brisbane, Queensland, Australia.
authors.forename: Paul M
authors.initials: PM
authors.lastname: Griffin
authors.affiliation: Q-Pharm Pty Limited, Brisbane, Queensland, Australia.
authors.forename: Suzanne L
authors.initials: SL
authors.lastname: Elliott
authors.affiliation: Faculty of Health, School of Biomedical Sciences, Queensland University of Technology, Brisbane, Queensland, Australia.
authors.forename: Kerry J
authors.initials: KJ
authors.lastname: Manton
mesh_terms: D000293:Adolescent; D000328:Adult; D001663:Bilirubin / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D017321:Clinical Trials, Phase I as Topic; D005215:Fasting / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019518:Postprandial Period; D012016:Reference Values; D012189:Retrospective Studies; D012737:Sex Factors; D015854:Up-Regulation; D055815:Young Adult
chemical_list: D015415:Biomarkers; D001663:Bilirubin
keywords: Analytical Methods; Biochemistry; Liver; Metabolism