Body Weight, Sleep, and Heart Health

Circadian Mechanisms of Cardiovascular Risk in Obesity

A multidisciplinary investigation examining the circadian mechanisms regulating cardiovascular (CV) risk, with an additional focus on obesity. Specifically, in a valid circadian protocol, the investigators aim to study resting cardiovascular risk markers and the reactivity of circadian rhythms in these risk markers to standardized stressors. It is intended to compare results in lean and obese individuals to determine if there are specific risks across the circadian cycle specific to obesity. Furthermore, using an exploratory approach, the investigators propose to explore impairment in pre/post synaptic function in the cardiac left ventricle.

Overall, these studies will help us answer whether the circadian system predispose individuals to increased CV disease risk - particularly around the vulnerable morning period, and whether these risks differ with obesity. The results will serve as a foundation for clinical trials of appropriately timed dosing of medications targeting aspects of the CV system that increase effectiveness while decreasing side effects, and may have particular relevance to management of CV risk in people with obesity.

Inclusion Criteria:

• Ages 25-65
• Lean and overweight (BMI 18.5-40kg/m2)
• Habitually sedentary

Exclusion Criteria:

• History of smoking/tobacco use
• Insomnia
• Moderate to severe obstructive sleep apnea.
• Prior shift work within 6 months prior to the study.
• Prescription medications
• Drugs of abuse
• Acute, chronic, or debilitating medical condition (including diabetes, hypertension, and metabolic syndrome)