Metabolomics of the Dietary Approaches to Stop Hypertension (DASH) Dietary Pattern

Completed

• Conditions: Blood Pressure; Dietary Modification
• Interventions: Behavioral: Fruits and vegetables diet; Behavioral: DASH diet; Behavioral: Control diet

• Registration Number: NCT03403166
• Lead Sponsor: Johns Hopkins Bloomberg School of Public Health

Brief Summary

The present record represents a secondary data analysis of the Dietary Approaches to Stop Hypertension (DASH) trial. Study data and specimens were accessed through the National Heart, Lung, and Blood Institute (NHLBI) Biologic Specimen and Data Repository Coordinating Center (BioLINCC). A global, untargeted, metabolomic profile was used to investigate biomarkers of the DASH dietary pattern as well as blood pressure change.

Detailed Description

The present study was conducted in order to: 1) quantify the metabolomic expression of the DASH dietary pattern; and 2) examine the relationship between metabolites that reflect the DASH dietary pattern and blood pressure change. This secondary data analysis leverages the completed DASH trial, a randomized feeding trial (N=459).

Study Timeline

• Study Start: 1993-08
• Primary Completion: 1997-07
• Study Completion: 2017-06
• Study First Submitted: 2017-12-21
• Status Verified: 2018-01
• Study First Submitted QC: 2018-01-17
• Last Update Submitted: 2018-01-17
• Study First Posted: 2018-01-18
• Last Update Posted: 2018-01-18

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 459

Inclusion Criteria

• Men and women with systolic blood pressure <160 mmHg and diastolic blood pressure 80-95 mmHg

Exclusion Criteria

• Taking anti-hypertensive medication
• Poorly controlled diabetes mellitus
• Hyperlipidemia
• Cardiovascular event within the past 6 months
• Chronic disease that may interfere with participation
• Pregnancy or lactation
• Body mass index > 35 kg/m2
• Unwilling to stop taking vitamin or mineral supplements or antacids
• Kidney disease
• Consumption of >14 alcoholic beverages per week
• Did not consent to the use of biological specimens
• Did not attend the 8 week follow-up visit
• No serum specimen or insufficient volume of serum specimens in repository

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
Fruits and vegetables diet	Fruits and vegetables diet	Potassium and magnesium intake was similar to the 75th percentile of U.S. consumption. Fiber intake was high. The fruits and vegetables diet consisted of more fruits and vegetables and fewer snacks and desserts than the control diet, but otherwise was similar to the control diet.
DASH diet	DASH diet	The DASH diet consisted of a high intake of fruits, vegetables, and low-fat dairy products. It included a wide range of sources of protein, such as meat, fish, poultry, nuts, and beans. Sugar-sweetened beverages, desserts, and red meat were restricted. In terms of nutrients, the DASH diet had a high amount of fiber and protein; low amounts of saturated fat, total fat, and cholesterol; and intake of potassium, magnesium, and calcium at levels close to the 75th percentile of U.S. consumption.
Control diet	Control diet	For the control diet, macronutrient intake was similar to average U.S. consumption and intake of potassium, magnesium, and calcium were similar to the 25th percentile of U.S. consumption. Sodium intake was approximately 3 g/day in each diet.

Primary Outcome Measures

Name	Time	Method
Serum metabolites	8 week follow-up visit	Metabolites were measured using a global, untargeted, metabolomic platform in serum specimens collected at the end of the 8 week diet intervention in the DASH trial. Reverse phase, untargeted ultrahigh-performance liquid chromatography tandem mass spectrometry quantification was used to measure metabolites. Peaks were quantified by calculating the area under the curve. Data were normalized to account for day-to-day instrumental variation. Compounds were identified by comparison to a library of purified standards or recurrent unknown entities and matches were determined based on retention time, mass-to-charge ratio, and chromatographic data. A relative measure of each metabolite (not absolute) is determined. The Metabolon (Durham, NC) platform quantifies over 1,000 compounds representing a broad range of metabolic compounds, including amino acids, carbohydrates, cofactors and vitamins, energy, lipids, nucleotides, peptides, and xenobiotics (chemicals, drugs, and food components).

Secondary Outcome Measures

Name	Time	Method
Blood pressure	8 week follow-up visit	The change in blood pressure was defined as the blood pressure level at the end of the 8 week diet intervention minus the blood pressure level at baseline.