Office of Public Affairs

4th Floor Koren Building
718 Fifth Avenue
Pittsburgh, PA 15219
Phone: 412.396.6050
Fax: 412.396.2243

    A A Email Print Share

    Circadian Rhythms May Be in Our Bones, Not Just Our Heads

    As the days get shorter and the nights grow longer, you may be fighting to stay awake at night or to get moving in the morning. Don't think you're becoming a slacker, says Dr. Paula Witt-Enderby, professor of pharmacology in Duquesne University's Mylan School of Pharmacy. It's likely caused by changing melatonin levels.  

    "Melatonin is known as the hormone of darkness, so its release is dependent, in part, upon the light/dark cycle," Witt-Enderby says. "This is an important molecule in your body because it tells your body if it is daytime or nighttime and it tells your body what season it is in, winter versus summer."  

    Disruptions in nighttime melatonin levels, as seen in shift workers, for example, produce adverse effects, such as a higher risk of breast, endometrial and prostate cancers as well as increases in the risk of hip and wrist fractures.

    Besides reflecting melatonin's key role in keeping the body aligned with the light/dark cycle, these disruptions and risks indicate that melatonin plays a role in cancer and bone loss protection. Witt-Enderby, in collaboration with Dr. Steven Lockley of Brigham and Women's Hospital, Harvard University, is studying the impact of light-or lack of light-on bone rhythms in blind women to begin to understand if and how bone metabolism may be regulated by the light/dark cycle. The findings from this study, reported at October's American Society for Bone and Mineral Research conference, may help to explain the loss of bone that occurs in shift workers. Other research Witt-Enderby has conducted shows a positive effect of melatonin on bone health.

    Yet, the question remains: How do we prevent bone loss due to light exposure at night?  
    Witt-Enderby suggests:

    • Wearing an eye mask to combat suppression of nocturnal melatonin levels
    • Turning off cell phones and computers
    • Remove all light sources from your bedroom
    • Taking a melatonin supplement at night.

    Currently, Witt-Enderby is conducting a clinical trial looking at a combination melatonin and micronutrient therapy on reversing bone loss in postmenopausal women who have osteopenia. Only six spots remain in this trial for post-menopausal women who have osteopenia (T-score -1.0 to -2.5) and are willing to participate in a one-year study. Participants will receive free bone density scans, health assessments, study supplements and parking. If interested, please contact Maria at 412.396.4296.

    Duquesne University

    Founded in 1878, Duquesne is consistently ranked among the nation's top Catholic research universities for its award-winning faculty and tradition of academic excellence. The University is nationally ranked by U.S. News and World Report and the Princeton Review for its rich academic programs in 10 schools of study for 10,000-plus graduate and undergraduate students, and by the Washington Monthly for service and contributing to students' social mobility. Duquesne is a member of the U.S. President's Higher Education Community Service Honor Roll with Distinction for its contributions to Pittsburgh and communities around the globe. The U.S. Environmental Protection Agency and the Princeton Review's Guide to Green Colleges acknowledge Duquesne's commitment to sustainability.