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

Metabolomics of the Dietary Approaches to Stop Hypertension (DASH) Dietary Pattern: A Secondary Data Analysis of the DASH Trial

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.

Study Overview

• Status: Completed
• Conditions: Blood Pressure; Dietary Modification
• Intervention / Treatment: Behavioral: DASH diet; Behavioral: Fruits and vegetables diet; Behavioral: Control diet

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 Type: Observational
• Enrollment (Actual): 459

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 22 years to 100 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

The study population consisted of men and women (aged 22 years and older) with systolic blood pressure <160 mmHg and diastolic blood pressure 80-95 mmHg who were not taking antihypertensive medication. The mean age was 44 years, about half were women, and approximately 2/3 were black or another race/ethnicity minority. The mean body mass index was 28 kg/m2 and mean blood pressure was 132/82 mmHg.

Description

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 Plan

How is the study designed?

Number of groups / cohorts

3

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
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.	Behavioral: DASH diet; Diet intervention
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.	Behavioral: Fruits and vegetables diet; Diet intervention
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.	Behavioral: Control diet; Diet intervention

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Serum metabolites	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).	8 week follow-up visit

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Blood pressure	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.	8 week follow-up visit

Collaborators and Investigators

• Sponsor: Johns Hopkins Bloomberg School of Public Health
• Collaborators: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
• Investigators: Principal Investigator: Casey M. Rebholz, PhD, MS, MPH, Johns Hopkins Bloomberg School of Public Health

Publications and helpful links

General Publications

• Appel LJ, Moore TJ, Obarzanek E, Vollmer WM, Svetkey LP, Sacks FM, Bray GA, Vogt TM, Cutler JA, Windhauser MM, Lin PH, Karanja N. A clinical trial of the effects of dietary patterns on blood pressure. DASH Collaborative Research Group. N Engl J Med. 1997 Apr 17;336(16):1117-24. doi: 10.1056/NEJM199704173361601.
• Rebholz CM, Lichtenstein AH, Zheng Z, Appel LJ, Coresh J. Serum untargeted metabolomic profile of the Dietary Approaches to Stop Hypertension (DASH) dietary pattern. Am J Clin Nutr. 2018 Aug 1;108(2):243-255. doi: 10.1093/ajcn/nqy099.

Study record dates

Study Major Dates

• Study Start (Actual): August 1, 1993
• Primary Completion (Actual): July 1, 1997
• Study Completion (Actual): June 1, 2017

Study Registration Dates

• First Submitted: December 21, 2017
• First Submitted That Met QC Criteria: January 17, 2018
• First Posted (Actual): January 18, 2018

Study Record Updates

• Last Update Posted (Actual): January 18, 2018
• Last Update Submitted That Met QC Criteria: January 17, 2018
• Last Verified: January 1, 2018

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Cardiovascular Diseases; Vascular Diseases; Hypertension
• Other Study ID Numbers: IRB00007383-2; K01DK107782 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No