Impact of Daylight on Patients With Acute Myocardial Infarction

Impact of Daylight on Period 2 Protein and Glycolytic Enzymes in Human Buccal Mucosa and Blood Samples

The study tests if intense light could be a potential therapy in humans after myocardial infarction by inducing Per2.

Damage to the heart caused by a myocardial infarction (heart attack) occurs most often during the early morning hours (6AM). Thus, the involvement of the circadian system (circa= approximately day) has been suggested. The circadian system in humans or animals is based on the rotation of the earth with day and night phases. When humans (or animals) wake up light shines in their eyes and the body receives a signal that the day starts. For the human body it means that certain proteins (named clock, period etc) are produced. The protein that determines the length of a day (awake and sleep period) is called Period 2 (Per2). Recent data indicated that the Per2 protein in hearts from mice is induced after daylight exposure (daylight with an intensity comparable to a bright day at the beach was used, approx. 10 000 LUX). This more Per2 was able to protect the heart from being damaged by no blood going to the heart (protection from a heart attack). This protection was based on a more efficient use of sugars (carbohydrates). Thereby the heart needs less oxygen. Current data indicate that human Per2 is also induced by light exposure and can be detected in human plasma samples. In this study Per2 transcript and protein levels will be analyzed in patients that just experienced a heart attack with and without intense light (daylight) therapy utilizing blood samples (erythrocytes and leukocytes).

Patients with myocardial infarction (MI): This group will be enrolled on the day of their MI. A blood draw will be performed before any light therapy. The patients will then receive a light box (Square One Wake Up Light NatureBright 10,000 LUX) that they shall use every morning from 8.30-9.00 AM for the next 2 weeks. At the conclusion of the two weeks another blood sample will be drawn.

Patients with myocardial infarction (MI): This group will be enrolled on the day of their MI and will only be exposed to room light. They will have blood drawn on the day of enrollment and then at 2 weeks after the MI.

Patients are exposed to day light for 2 weeks after a heart attack. At the end of 2 weeks they will have blood drawn.

Patients will be exposed to only room or natural light for 2 weeks after heart attack. At the end of 2 weeks they will have blood drawn.

Inclusion Criteria: Patients with an acute myocardial infarction Healthy volunteers Must speak and understand English Exclusion Criteria: Patients with an acute myocardial infarction but are too sick, e.g. severe symptoms, chest pain, generally unstable, etc.

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Brainard J, Gobel M, Bartels K, Scott B, Koeppen M, Eckle T. Circadian rhythms in anesthesia and critical care medicine: potential importance of circadian disruptions. Semin Cardiothorac Vasc Anesth. 2015 Mar;19(1):49-60. doi: 10.1177/1089253214553066. Epub 2014 Oct 7.

Eckle T, Hartmann K, Bonney S, Reithel S, Mittelbronn M, Walker LA, Lowes BD, Han J, Borchers CH, Buttrick PM, Kominsky DJ, Colgan SP, Eltzschig HK. Adora2b-elicited Per2 stabilization promotes a HIF-dependent metabolic switch crucial for myocardial adaptation to ischemia. Nat Med. 2012 Apr 15;18(5):774-82. doi: 10.1038/nm.2728.

http://www.ucdenver.edu/academics/colleges/medicalschool/departments/Anesthesiology/Research/labfacilities/LiCHTLab/Pages/default.aspx