Isometric Exercise for People With Raised Blood Pressure (IsoFIT-BP)

Feasibility Study to Assess the Delivery of a Novel Isometric Exercise Intervention for People With Stage 1 Hypertension in the NHS

High blood pressure affects many people in the United Kingdom. People with raised blood pressure (140-159/90-99 mmHg) are recommended to make changes in their lifestyle (e.g. smoking/alcohol/diet/exercise) and/or medication in order to reduce their blood pressure. Current knowledge suggests that a particular type of exercise - isometric exercise - can lower blood pressure. Isometric exercise involves holding a fixed body position for a short period of time. As most of the information about the benefits of this type of exercise comes from laboratory-based studies, researchers want to find out if it is possible for GP practices to offer NHS patients with clinically high blood pressure an isometric exercise plan to do at home and how it might affect their blood pressure over 6 months. They will also find out the experiences of those doing this type of exercise and whether it can be done consistently at home over time.

Study Overview

• Status: Completed
• Conditions: Hypertension
• Intervention / Treatment: Behavioral: Standard care lifestyle advice; Other: Isometric Exercise

• Study Type: Interventional
• Enrollment (Actual): 84
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Kingdom
  • Hove, United Kingdom, BN31AE
    • Brighton Health and Wellbeing Centre
  • Kent
    • Canterbury, Kent, United Kingdom, CT45BL
      • Canterbury Medical Practice
    • Canterbury, Kent, United Kingdom
      • Kent and Canterbury Hospital
    • Faversham, Kent, United Kingdom, ME138FH
      • Newton Place Surgery
  • Surrey
    • Carshalton, Surrey, United Kingdom, SM51AA
      • St Helier Hospital
  • West Sussex
    • Bognor Regis, West Sussex, United Kingdom, PO212UW
      • Maywood Healthcare Centre

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Aged 18 or over
• Clinic systolic BP 140-159 mmHg
• Able to provide informed consent

Exclusion Criteria:

• Currently taking anti-hypertensive medication
• White coat hypertension, as evidenced by averaged home systolic BP <135 mmHg
• Inability to undertake study intervention (isometric exercise)

• Previous history of any of the following:

  • Diabetes mellitus (Type 1 or type 2)
  • Ischaemic heart disease (myocardial infarction and/or coronary angina and/or coronary revascularization procedure)
  • Moderate or severe stenotic or regurgitant heart valve disease
  • Atrial or ventricular arrhythmia
  • Stroke or transient ischaemic attack
  • Aortic aneurysm and/or peripheral arterial disease
  • Uncorrected congenital or inherited heart condition
• Estimated glomerular filtration rate <45 ml/min (calculated using CKD-EPI or MDRD formulae, and taking most recent documented results)
• Documented left ventricular ejection fraction <45% and/or left ventricular hypertrophy (by either echocardiography or standard ECG criteria e.g. Sokolow-Lyon)
• Documented urine albumin:creatinine ratio >3.5 mg/mmol
• Inability to provide informed consent
• If female, pregnancy or currently breast feeding
• Enrolled in another Clinical Trial of an Interventional Medicinal Product or Medical Device or other interventional study
• Medical condition that, in the opinion of the investigator, would make the participant unsuitable for the study

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: Control; To receive standard care lifestyle advice only	Behavioral: Standard care lifestyle advice; Healthy lifestyle advice for hypertension, given by a healthcare professional.
Experimental: Isometric Exercise; To receive standard care lifestyle advice plus 3 sessions of isometric exercise per week	Behavioral: Standard care lifestyle advice; Healthy lifestyle advice for hypertension, given by a healthcare professional.; Other: Isometric Exercise; Prescribed 6 months of isometric exercise training (three sessions per week, comprised of 4 x 2-minute bouts with 2-minute recovery periods in-between).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Experience of intervention delivery	Qualitative focus groups with health care professionals identifying the type and number of each barrier and facilitator, of the practical delivery of isometric exercise intervention.	Project month 11
Change in systolic blood pressure (mmHg) from baseline to Week 4.		Participant week 4
Change in systolic blood pressure (mmHg) from baseline to Month 3.		Participant 3 months
Change in systolic blood pressure (mmHg) from baseline to Month 6.		Participant 6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Early fidelity of the isometric exercise prescription.	Assessed by checking whether individual participant's heart rate (bpm) measures fall within 95% of their peak heart rate confidence intervals following the first three training sessions.	Participant week 1
Short-term fidelity of the isometric exercise prescription.	Assessed by checking whether individual participant's heart rate (bpm) measures fall within 95% of their peak heart rate confidence intervals following the first four weeks (12) of training sessions.	Participant week 4
Short-term adherence to the Isometric exercise (IE) training.	Measured using the proportion of participants (number) completing a minimum of 8 of 12 IE sessions up to the 4-week point.	Participant week 4
Mid-term adherence to the Isometric exercise training.	Measured using the proportion of participants (number) completing a minimum of two thirds of all IE sessions up to 3 months.	Participant 3 Months
Long-term adherence to the Isometric exercise training.	Measured using the proportion of participants (number) completing a minimum of two thirds of all IE sessions up to 6 months.	Participant 6 Months
Recruitment rates from data collected at sites.	This will be measured by calculating the average number of participants recruited per week.	Project month 10
Short-term attrition rates from data collected at sites.	This will be measured by calculating the number of withdrawals from the study up to 4 weeks.	Participant week 4
Mid-term attrition rates from data collected at sites.	This will be measured by calculating the number of withdrawals from the study up to 3 months.	Participant 3 months
Long-term attrition rates from data collected at sites.	This will be measured by calculating the number of withdrawals from the study up to 6 months.	Participant 6 months
Change in diastolic blood pressure (mmHg) from baseline to Week 4.		Week 4
Change in diastolic blood pressure (mmHg) from baseline to Month 3.		Month 3
Change in diastolic blood pressure (mmHg) from baseline to Month 6.		Month 6
Experience of isometric exercise intervention.	Qualitative focus groups with study participants identifying the number of positive and negative experiences of the isometric exercise intervention and taking part in the study.	Month 11
Participant experiences of undertaking isometric exercise.	Collected using participant study-specific survey with closed and open questions.	Participant week 4.
Subjective opinion of healthcare professionals on their willingness to consider the intervention as a treatment option for patients with Stage 1 hypertension.	Collected using semi-structured interviews conducted by telephone with healthcare professionals from GP practices not taking part as study recruitment sites.	Project month 11.
Short-term Quality-adjusted life years (QALYs) calculated from patients' responses to the EQ-5D-5L questionnaire.	The health profile established from EQ-5D-5L will be converted into a utility index (0 and 1) using the validated mapping function to derive utility values for EQ-5D-5L from the existing EQ-5D-3L. These utilities will be multiplied by the time spent in each state to generate QALYs.	Participant 4 weeks
Mid-term Quality-adjusted life years calculated from patients' responses to the EQ-5D-5L questionnaire.	The health profile established from EQ-5D-5L will be converted into a utility index (0 and 1) using the validated mapping function to derive utility values for EQ-5D-5L from the existing EQ-5D-3L. These utilities will be multiplied by the time spent in each state to generate QALYs.	Participant 3 months
Long-term Quality-adjusted life years calculated from patients' responses to the EQ-5D-5L questionnaire.	The health profile established from EQ-5D-5L will be converted into a utility index (0 and 1) using the validated mapping function to derive utility values for EQ-5D-5L from the existing EQ-5D-3L. These utilities will be multiplied by the time spent in each state to generate QALYs.	Participant 6 months
Healthcare resource utilisation (a).	Measuring healthcare access by using the number of GP visits at 4 weeks.	Participant 4 weeks.
Healthcare resource utilisation (a).	Measuring healthcare access by using the number of GP visits at 3 months.	Participant 3 months
Healthcare resource utilisation (a).	Measuring healthcare access by using the number of GP visits at 6 months.	Participant 6 months
Healthcare resource utilisation (b).	Measuring healthcare access by using the number of nurse visits at 4 weeks.	Participant 4 weeks.
Healthcare resource utilisation (b).	Measuring healthcare access by using the number of nurse visits at 3 months.	Participant 3 months.
Healthcare resource utilisation (b).	Measuring healthcare access by using the number of nurse visits at 6 months.	Participant 6 months.
Healthcare resource utilisation (c).	Measuring healthcare access by using the number of other health professionals visits at 4 weeks.	Participant 4 weeks.
Healthcare resource utilisation (c).	Measuring healthcare access by using the number of other health professionals visits at 3 months.	Participant 3 months.
Healthcare resource utilisation (c).	Measuring healthcare access by using the number of other health professionals visits at 6 months.	Participant 6 months.
Healthcare resource utilisation (d).	Measuring healthcare access by using the number of number of A&E attendances at 4 weeks.	Participant 4 weeks.
Healthcare resource utilisation (d).	Measuring healthcare access by using the number of number of A&E attendances at 3 months.	Participant 3 months.
Healthcare resource utilisation (d).	Measuring healthcare access by using the number of number of A&E attendances at 6 months.	Participant 6 months.
Healthcare resource utilisation (e).	Measuring healthcare access by using the number of number of inpatient hospital admissions at 4 weeks.	Participant 4 weeks.
Healthcare resource utilisation (e).	Measuring healthcare access by using the number of number of inpatient hospital admissions at 3 months.	Participant 3 months.
Healthcare resource utilisation (e).	Measuring healthcare access by using the number of inpatient hospital admissions at 6 months.	Participant 6 months.
Healthcare resource utilisation (f).	Measuring healthcare access by using the number of inpatient diagnostic tests at 4 weeks.	Participant 4 weeks.
Healthcare resource utilisation (f).	Measuring healthcare access by using the number of inpatient diagnostic tests at 3 months.	Participant 3 months.
Healthcare resource utilisation (f).	Measuring healthcare access by using the number of inpatient diagnostic tests at 6 months.	Participant 6 months.
Intervention costs.	This will be measured by calculating the time cost of the training team and healthcare professionals, the cost of supplies and the equipment necessary to implement the intervention.	Participant 4 weeks.
Intervention costs.	This will be measured by. calculating the time cost of the training team and healthcare professionals, the cost of supplies and the equipment necessary to implement the intervention.	Participant 3 months.
Intervention costs	This will be measured by calculating the time cost of the training team and healthcare professionals, the cost of supplies and the equipment necessary to implement the intervention.	Participant 6 months.
Medication at short-term time point (a)	Measured using the frequency per week in days, start and end date per medication at 4 weeks.	Participant 4 weeks.
Medication at mid-term time point (a)	Measuring the frequency per week in days, start and end date per medication at 3 months.	Participant 3 months.
Medication at long-term time point (a)	Measuring the frequency per week in days, start and end date per medication at 6 months.	Participant 6 months.
Medication at short-term time point (b)	Measured using the dosage per day (mg), start and end date per medication at 4 weeks.	Participant 4 weeks.
Medication at mid-term time point (b)	Measuring the dosage per day (mg), start and end date per medication at 3 months.	Participant 3 months.
Medication at long-term time point (b)	Measuring the dosage per day (mg), start and end date per medication at 6 months.	Participant 6 months.

Collaborators and Investigators

• Sponsor: East Kent Hospitals University NHS Foundation Trust
• Collaborators: University of Kent; Canterbury Christ Church University
• Investigators: Study Director: Christopher K Farmer, University of Kent

Study record dates

Study Major Dates

• Study Start (Actual): February 1, 2020
• Primary Completion (Actual): November 30, 2022
• Study Completion (Actual): November 30, 2022

Study Registration Dates

• First Submitted: April 19, 2021
• First Submitted That Met QC Criteria: June 14, 2021
• First Posted (Actual): June 23, 2021

Study Record Updates

• Last Update Posted (Actual): September 15, 2023
• Last Update Submitted That Met QC Criteria: September 14, 2023
• Last Verified: September 1, 2023

More Information

Terms related to this study

• Keywords: Exercise; Hypertension; General practice; Feasibility study; High blood pressure; Isometric exercise
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Vascular Diseases; Hypertension
• Other Study ID Numbers: NIHR200485; 13472393 (Registry Identifier: ISRCTN)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: The datasets generated during and/or analysed during the current study are/will be available upon request from Dr Jonathan Wiles (jim.wiles@canterbury.ac.uk). The data will become available 1 year after the study finishes which will be approximately December 2022 and may be accessed for up to 5 years. Anonymised data may be accessed by researchers at universities, NHS organisations or other healthcare providers where the sharing of data has a clearly defined purpose and its use will be of benefit to wider society. Data will be shared by secure data transfer. Consent from participants was obtained for the use of their information for future research and to be shared anonymously with other researchers.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; CSR

Drug and device information, study documents

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