Measuring Individual Responses to a Wholegrains and Nuts Intervention to Reduce Blood Pressure in Prehypertension

NCT04326686 | Completed DMC

• 1 other identifier: MI-DIET
• Study Type: interventional
• Target: 12
• Locations: 1 country
• Sites: 1

Brief Summary

The aim of the study is to investigate whether physiological, psychological and environmental factors, at an individual level, modify a) adherence, and b) blood pressure response, to a nuts and wholegrains intervention in participants at risk for developing high blood pressure. For 24 weeks, participants will, on a daily basis, monitor their own blood pressure using a wireless blood pressure monitor and respond to short semi-personalised questionnaires using a wrist-worn device, which also measures activity levels. Participants will receive an intervention of wholegrain foods and nuts to substitute into their diets for 8 weeks, between two 8-week observation periods. The length of the study periods will enable repeated measurements to be taken, in order to assess what factors, on an individual level, are associated with fluctuations in the outcomes. This will provide an insight into the types of factors that can help to explain individual fluctuations in adherence and physiological outcomes, such as blood pressure, that are common in nutrition studies. In the future, this should help in tailoring the way the investigators deliver effective individualised interventions, and enable researchers to be better able to consider and control for factors that can affect adherence and response to dietary interventions.

Conditions

Prehypertension

Keywords

N-of-1; Ecological Momentary Assessment; Blood pressure; Whole grains; Nuts

Outcome Measures

Primary Outcomes (3)

• Adherence to wholegrains and nuts consumption

  Number of portions of wholegrains consumed and whether a portion of nuts were consumed, reported daily via the PRO-Diary wrist device.

  8-week intervention period

• Change in plasma alkylresorcinol levels reflecting wholegrains intake

  Concentration of alkylresorcinols as a measure of wholegrains intake in nmol/L

  Every 4 weeks from start of study up to 24 weeks

• Change in blood pressure

  Blood pressure (both systolic and diastolic) will be taken daily by participants via the QardioArm wireless blood pressure monitor. 3 measurements are taken automatically and averaged.

  From start of study up to 24 weeks

Secondary Outcomes (4)

• Correlation between adherence and blood pressure change

  8-week intervention period

• Total, LDL and HDL cholesterol levels

  4-week blood samples

• Amount of wholegrains and nuts consumed during follow-up reported using PRO-Diary questionnaires

  8-week follow-up phase

• Determination of personal factors which correlate with study outcomes using Ecological Momentary Assessment (EMA) through the PRO-Diary device

  24 weeks

Study Arms (1)

N-of-1 study

OTHER

For 24 weeks, each participant will measure their blood pressure and respond to questionnaires daily, and visit the institute to provide a blood sample every 4 weeks. The study is split into three 8-week phases, the first of which will start when each participant is enrolled. For the first 8-week observation phase (A1) the participant is instructed to continue with their usual diet and exercise habits. For the second 8-week intervention phase (B), the participant will be provided with wholegrains and nuts and recommended to substitute these in place of refined grains and other snacks, respectively. They will also receive dietary advice for following the Dietary Approaches to Stop Hypertension (DASH) diet. For the final 8 week follow-up period (A2), provision of wholegrains and nuts will cease but the participant will continue with measurements at the same frequency as previously.

Other: Dietary intervention: nuts and wholegrains with dietary advice for a blood-pressure lowering diet

Interventions

Dietary intervention: nuts and wholegrains with dietary advice for a blood-pressure lowering diet OTHER

30g mixed unsalted tree nuts (almonds, hazelnuts and almonds) per day; 3 portions of wholegrain foods per day (including wholegrain cereal products, wholegrain bread and wholegrain pasta); guidance for following the Dietary Approaches to Stop Hypertension (DASH) diet

N-of-1 study

Eligibility Criteria

• Age: 18 Years - 75 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Mildly elevated blood pressure levels: systolic blood pressure (SBP) \>120 \<=140mmHg and/or diastolic blood pressure (DBP) \>80 \<=90mmHg.
• Low habitual intake of wholegrains: \<=7 portions/week
• Body Mass Index (BMI) between 18-35
• Possessing a smartphone capable of running the Qardio app in conjunction with the QardioArm wireless blood pressure monitor

You may not qualify if:

• SBP \<120 or \>140mmHg or DBP \<80 or \>90mmHg. Participants with SBP \> 140 or DBP \> 90 will be advised to visit their GP to have their blood pressure reassessed in a clinical setting.
• Diagnosed with diabetes
• Clinically diagnosed with hypertension or hypercholesterolemia
• Unstable or untreated thyroid disorder
• Taking blood pressure- or cholesterol-lowering medications (e.g. beta blockers or statins)
• Following a low carbohydrate/gluten free diet
• Coeliac disease/gluten insensitivity
• Any food allergies
• Being on a weight loss diet or having lost \>5kg in the last 6 months
• Any history of an eating disorder
• \>7 portions/week habitual wholegrains consumption
• Having taken part in a study where wholegrains were provided in the last 3 months
• Not possessing a smartphone to run the Qardio app.

Sponsors & Collaborators

• University of Aberdeen: lead
• Biotechnology and Biological Sciences Research Council: collaborator
• Unilever R&D: collaborator

Study Sites (1)

The Rowett Institute, University of Aberdeen

Aberdeen, Aberdeen City, AB25 2ZD, United Kingdom

Location

MeSH Terms

Conditions

Prehypertension

Interventions

Nutrition Assessment

Condition Hierarchy (Ancestors)

Vascular Diseases; Cardiovascular Diseases

Intervention Hierarchy (Ancestors)

Data Collection; Epidemiologic Methods; Investigative Techniques; Health Care Evaluation Mechanisms; Quality of Health Care; Health Care Quality, Access, and Evaluation; Epidemiologic Measurements; Public Health; Environment and Public Health

Study Officials

• Baukje de Roos

  The Rowett Institute, University of Aberdeen

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: PREVENTION
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: This is a series of N-of-1 studies where data from each participant will be analysed separately. Each study follows an A1-B-A2 design consisting of an initial observation phase, an intervention phase and a follow-up phase, each of 8 weeks duration.

Study Record Dates

• First Submitted: March 20, 2020
• First Posted: March 30, 2020
• Study Start: October 30, 2020
• Primary Completion: March 25, 2022
• Study Completion: March 25, 2022
• Last Updated: May 17, 2022

Record last verified: 2022-05

Data Sharing

• IPD Sharing: Will not share

Locations

GB (1)