Chronobiology of Meal Timing: Effects on Vascular and Renal Function

Study Overview
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Brief Summary
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The purpose of this study us to investigate the effects of mistimed eating on blood pressure, kidney function and vascular function.

Detailed Description
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Despite advancements in pharmacologic antihypertensives, hypertension currently affects 1 in 3 Americans and accounts for more than $50 billion of health care spending. Importantly, hypertension is the leading cause of cardiovascular (CVD) and kidney diseases (CKD). As a result, the AHA/ACC lowered the diagnostic criteria for hypertension to encourage earlier preventative lifestyle intervention. There is a critical need to identify and implement novel lifestyle interventions in individuals with early-stage hypertension to prevent the subsequent development of CVD and CKD. Chronotherapy that aligns behavioral cues (such as time of eating) with the body's internal biological clocks, has gained much attention as a potential strategy to prevent and manage hypertension, however, the underlying mechanisms are not yet fully understood. The purpose of this study is to investigate the effects of mistimed eating on blood pressure, kidney function and vascular function.

Official Title
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Chronobiology of Meal Timing: Effects on Vascular and Renal Function

Conditions
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Hypertension

Intervention / Treatment
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* Other: Morning meal challenge
* Other: Evening meal challenge


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Men and Women aged 18-45 years Elevated (SBP 120-129; DBP <80 mmHg) or stage 1 hypertension (SBP 130-139; DBP 80-89 mmHg) Exclusion Criteria: History of chronic disease (CV, lung, cancer, renal, sleep apnea, diabetes, autoimmune) Anti-hypertensive medication use Currently pregnant or lactating Current shift worker Travel >3 time zones four weeks before the start of the study or during the study Insomnia Practiced intermittent fasting in past six months Current nicotine use Current hormone replacement therapy Current melatonin use Current use of antioxidants and unwilling to stop taking them for the duration of the study Unable to provide informed consent

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Morning Meal Challenge<br> | Other: Morning meal challenge<br>* A Western-style diet meal which will be individualized for caloric consumption by estimated total daily energy expenditure eaten after 1 hour of waking up in the morning<br>|
| Experimental: Late Night Meal Challenge<br> | Other: Evening meal challenge<br>* A Western-style diet meal which will be individualized for caloric consumption by estimated total daily energy expenditure eaten within 1 hour of going to bed<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Urinary sodium excretion and markers of kidney injury | Day and nocturnal urinary sodium, NGAL and KIM-1 | 24 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 24hr ambulatory blood pressure | Day and nocturnal ambulatory blood pressure | 24 Hours | 
| Macrovascular function | Brachial artery endothelial function assessed by flow mediated dilation | At baseline and after each 24hour experimental arm | 
| Microvascular function | Skin blood flow response to local heating measured by laser doppler flowmetry | At baseline and after each 24hour experimental arm |