Circadian and Sleep Epidemiology Laboratory (CASEL)

Ramaley N368B

Department of Integrative Physiology
University of Colorado
Boulder, CO 80309-0354
Office Phone: 303-735-7377
Fax: 303-492-0811

Research Interests

We use large, observational data sets to query associations of circadian phenotypes, circadian misalignment, sleep, and work hours with health and longevity. Our work aims to identify modifiable risk factors in the realm of circadian and sleep research that can be leveraged for prevention strategies in real life settings.

Current interests include:

  1. Cardio-metabolic consequences of circadian misalignment and sleep deprivation
  2. Work hour characteristics, occupational safety, and health
  3. Effects of sleep, and the mismatch between chronotype and work hours on mood
  4. Quantification of light exposure in real life
  5. Circadian phenotyping


  • DirectorDr. Céline Vetter
  • Post-doctoral Fellow: TBD
  • Graduate Students: TBD
  • Undergraduate Students: Kendra Downer, Larissa Hunt, Akram Imam, Connor Phibbs, Annika Reuter.
  • Collaborators: Richa Saxena, Ph.D., Jacqueline Lane, Ph.D., and Hassan Dashti, Ph.D., Massachusetts General Hospital, Center for Medical Genomics, Harvard Medical School/Broad Institute of MIT and Harvard; Frank Scheer, Ph.D., Harvard Medical School; Martin Rutter, M.D. and Simon Anderson, University of Manchester, UK; Andrew J.K. Phillips, Ph.D., Harvard Medical School, USA and Monash University, Australia; Elizabeth Klerman, M.D., Ph.D. and Dorothee Fischer, Ph.D., Harvard Medical School; Eva Schernhammer, M.D., Ph.D. and Susanne Strohmeier, Ph.D., Channing Division of Network Medicine, Brigham and Women’s Hospital, and Medical University of Vienna, Austria; Kyriaki Papantoniou, M.D., Ph.D., Medical University of Vienna, Austria; Linda van Kerkhof, Ph.D., Centre for Health Protection, National Institute for Public Health and the Environment, Bilthoven, The Netherlands; Sanjay Patel, M.D., M.S., University of Pittsburgh Medical Campus Sleep Laboratory, Pittsburgh, PA; Phyllis Zee, M.D., Ph.D. and Kathryn Reid, Ph.D., Northwestern Feinberg School of Medicine, and Center for Sleep and Circadian Biology, Northwestern University; Laura Barger, Ph.D., Matthew Weaver, Ph.D., and Charles Czeisler, M.D., Ph.D., Division of Sleep and Circadian Disorders, Brigham and Women’s Hospital and Harvard Medical School; Till Roenneberg, Ph.D. and Eva Winnebeck, Ph.D., Institute of Medical Psychology, Ludwig-Maximilian-University, Munich, Germany; Sylvia Rabstein, Ph.D. and Katarzyna Gawrych, Ph.D., Institut für Prävention und Arbeitsmedizin der Deutschen Gesetzlichen Unfallversicherung, Ruhr Universität Bochum, Germany.

Current Research Projects

  • Sleep and cardio-metabolic health in the Hispanic Community Health Study (HCHS)/SOL
  • Contemporary shift schedules and its association with sleep patterns and circadian strain in Nurses' Health Study 3
  • Light and health in the Hispanic Community Health Study (HCHS)/SOL
  • Sleep and Shift Work in relation to cardio-metabolic health in UK Biobank

Opportunities for Undergraduates

Undergraduates who seek research experience in human circadian and sleep epidemiology must have:

  • Either completed or be currently enrolled in IPHY 2800 (Introductory Statistics)
  • An interest in using epidemiological and statistical tools to study health
  • Enroll in Independent Study (i.e. IPHY 4860) for 8-10 hours/week for at least one semester.

For more information, contact Prof. Céline Vetter (

Recent Publications