Sedentary Behavior, Cardiovascular Function, and Sleep

Sedentary Behavior, Cardiovascular Function, and Sleep

This is an interventional study that will examine how sedentary behavior (decreased physical inactivity) over time affects cardiovascular health (i.e. heart rate and blood pressure) and sleep quality/duration.

PRIMARY OBJECTIVES:

1. To test the hypothesis that two weeks of sedentary behavior will progressively impair vascular endothelial function.

2: To test the hypothesis that increasing sedentary behavior will decrease total sleep duration and sleep efficiency.

3: To test the hypothesis that two-weeks of sedentary behavior will progressively increase 24-h blood pressure and reduce nocturnal blood pressure dipping.

OUTLINE:

After a baseline period, participants will become more inactive and also come in for 4-h uninterrupted sitting visits. Cardiovascular, activity, and sleep measures will be taken throughout.

Inclusion Criteria:

• Ages 20-80y
• Lean and overweight (BMI 18.5-40 kg/m2)
• No acute, chronic, or debilitating medical conditions
• No prescription/non-prescription medications or drugs of abuse
• Limited weight training or intense exercise (swimming, CrossFit)
• Non-smoker
• Average level of daily physical activity (8,000-12,499 steps/day)
• Persons who fit all the above criteria and are suitable based on a medical history and health habits questionnaire, sleep profiling questionnaire, and electrocardiogram and clinical biochemical screening tests of blood and urine may be eligible to participate.

Exclusion Criteria:

• Persons with any acute, chronic, or debilitating medical condition except pre-hypertension and/or mild to moderate sleep apnea will be excluded.
• Persons with any symptoms of acute or active illness (e.g. fever, leukocytosis) will be excluded.
• Persons with a history of severe psychiatric illness or psychiatric disorders will be excluded.
• Persons with a history of regular night/or rotating shift work, or who have traveled more than three time zones during the one month prior to the study will be excluded.
• Pregnant persons, decisionally impaired adults, and prisoners will be excluded.