Medical Chronobiology Program (MCP)
Research on Circadian Rhythms in Health and Disease
Dr. Scheer describing work done at the MCP
The Medical Chronobiology Program (MCP), an interdisciplinary research program at Brigham and Women’s Hospital to foster the translational research in sleep and circadian biology to understand the basis behind time-variant changes in disease severity as well as effects of circadian misalignment (typical in night shift workers), the effect of not just what we eat but also when we eat, and their interaction with genetics (e.g., MTNR1B).
The severity of many diseases varies across the 24-hour period. For example, heart attacks occur most frequently in the morning a few hours after waking up, temporal lobe epileptic seizures of the brain’s temporal lobe usually occur in the late afternoon or early evening, and asthma is generally worst at night. The goal of the MCP is to determine whether or not these changes are caused by the body clock (the endogenous circadian pacemaker) or attributable to behaviors that occur on a regular daily basis, including the sleep/wake, rest/activity, and fasting/eating cycles. We investigate the impact of circadian misalignment on cardiovascular, immune, and metabolic regulation and whether they may help explain the increased risk for diabetes, obesity, and cardiovascular disease among shift workers. We are especially interested in the effect of food intake on metabolism dependent on the time of intake, determining whether we can use timed eating as a countermeasure against the adverse effects of circadian misalignment, and study interindividual differences based on sex and genetics, especially the common type-2 diabetes risk variant of the melatonin receptor gene MTNR1B. Understanding the biological basis of these changes across the day and night may provide insight into the underlying cause of the disease and could lead to better therapy (e.g., appropriately timed medication, light, exercise or food to target specific phases of the body clock).
To investigate these effects, we study both healthy and diseased human volunteers in field settings as well as in a highly-controlled laboratory setting with intensive physiological monitoring of energy balance, glucose control, blood pressure, the immune system, neuroendocrine regulation, thermoregulation and neurocognitive control. In the laboratory studies we can separately adjust the timing of their environmental lighting and scheduled behaviors including the sleep/wake cycle, exercise and nutrient intake. Our field studies take place over a range of several days to a year, while our laboratory studies span multiple days to weeks. In certain laboratory studies, volunteers have no knowledge of the time; in this way, we can schedule all behaviors to occur at all phases of the body clock, which allows us to analyze the data for the separate influences from circadian and behavioral factors. In addition, we investigate the interaction between the circadian timing system and therapy in the treatment of, e.g., hypertension, nocturnal asthma and hyperglycemia.
|Frank A.J.L. Scheer, PhD||Marta Garaulet, MPH, PhD|
|Kun Hu, PhD||Richa Saxena, PhD||Steven A. Shea, PhD||Ali Tavakkoli, MD|
|Ivy C. Mason, PhD||Jingyi Qian, PhD||Nina Vujovic, PhD|
|Hoa Nguyen||Jordan Owens||Ioanna Tegos|
Medical Chronobiology Program, Division of Sleep Medicine, BWH
221 Longwood Ave
Boston, MA 02115