Photobiomodulation Effects on Blood Pressure and Vascular Function in Treated Hypertensive Patients

Effect of Vascular Photobiomodulation on Cardiovascular Parameters of Treated Hypertensive Patients: A Randomized and Controlled Clinical Trial

This double-blind, randomized, sham-controlled clinical trial aims to evaluate the effects of vascular photobiomodulation on blood pressure and vascular function in hypertensive patients treated with losartan. A total of 80 patients using losartan (100 mg/day for at least two months) will be recruited and followed for 4 weeks. Participants will be randomly allocated to either an active photobiomodulation group or a sham control group.

Study Overview

• Status: Not yet recruiting
• Conditions: Hypertension
• Intervention / Treatment: Device: Vascular Photobiomodulation; Device: Sham Photobiomodulation

Detailed Description

This is a double-blind, parallel-group, randomized, sham-controlled clinical trial. A total of 80 hypertensive patients under stable treatment with losartan (100 mg/day for at least two months) will be recruited and randomly allocated (1:1) to one of the following groups:

• Photobiomodulation Group;
• Sham Control Group.

The intervention will last 4 weeks, with two sessions per week, totaling 8 sessions. Each session will last 30 minutes.

The photobiomodulation intervention will consist of laser irradiation applied over the radial artery using a red laser (wavelength: 660 nm; power: 100 mW; duration: 30 minutes per session; total energy: 180 J per session). The sham group will undergo an identical procedure; however, the laser emission will be blocked to ensure no therapeutic effect. Blinding will be maintained for all participants and outcome assessors, with only the technician responsible for device setup aware of group allocation.

Assessments will be conducted at the following time points:

• Before and after the first intervention session (acute effects);
• Before and after the final intervention session (chronic effects).

Outcome measures will include:

• Blood pressure: office blood pressure (systolic and diastolic) measured using validated automated devices, and residential blood pressure monitoring throughout the study period using standardized protocols.
• Vascular function: endothelial function assessed by brachial artery flow-mediated dilation using Doppler ultrasound, following established guidelines.

Additional measures:

- Heart rate at rest and during assessments.

This study is designed as a feasibility trial to explore the potential synergistic effects of vascular photobiomodulation combined with losartan therapy in hypertensive patients without major comorbidities.

• Study Type: Interventional
• Enrollment (Estimated): 80
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Celso Muniz, MD; Phone Number: +55 11 98369-6696; Email: freitas_celso@uol.com.br

Study Locations

• Brazil
  • São Paulo
    • São Paulo, São Paulo, Brazil, 01525-000
      • Raphael Dias
      • Contact: Celso Muniz, MD; Phone Number: +55 11 98369-6696; Email: freitas_celso@uol.com.br

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Patient in use of losartan at a dose of 100 mg/day divided into two doses as the only antihypertensive medication, for a minimum of 2 months.
• Present systolic blood pressure is less than or equal to 140 mmHg and diastolic less than or equal to 90 mmHg.
• Not having used any other antihypertensive medication in the last 2 months.
• Age between 18 and 65 years
• If female, not pregnant
• No cutaneous/subcutaneous lesions on both arms.
• No musculoskeletal, rheumatic, cardiovascular, metabolic, neurological, oncological, immunological, hematological, psychiatric or cognitive diagnoses and that may be worsened by the intervention or prevent the correct application of FBM vascular.

Exclusion Criteria:

• Changes in medication status during the study

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Photobiomodulation; Participants will receive vascular photobiomodulation therapy applied over the radial artery using a red laser (wavelength: 660 nm; power: 100 mW). Each session will last 30 minutes, with a total energy delivery of 180 J per session. Sessions will be performed twice per week for 4 weeks.	Device: Vascular Photobiomodulation; Vascular photobiomodulation therapy applied over the radial artery using a red laser (wavelength: 660 nm; power: 100 mW).
Sham Comparator: Sham Photobiomodulation; Participants will undergo an identical procedure to the experimental group; however, the laser emission will be blocked to ensure no therapeutic effect. All procedures, duration, and frequency will be identical to the experimental group to maintain blinding.	Device: Sham Photobiomodulation; Laser emission will be blocked to ensure no therapeutic effect

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Brachial Artery Vascular Function	Flow-mediated dilation (FMD, %) of the brachial artery assessed by Doppler ultrasound. Higher values indicate better endothelial function	Baseline and 4 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Resting Systolic and Diastolic Blood Pressure	Systolic and diastolic blood pressure (mmHg) measured under standardized resting conditions using validated automated devices. Lower values indicate improvement	Baseline and 4 weeks
Acute Change in Brachial Artery Vascular Function	Flow-mediated dilation (FMD, %) of the brachial artery assessed by Doppler ultrasound before and after the intervention session, following current guidelines. Higher values indicate better endothelial function	Baseline and 4 weeks
Acute Change in Resting Blood Pressure	Systolic and diastolic blood pressure (mmHg) measured immediately before and after the intervention session using validated automated devices.	Baseline and 4 weeks
Change in Residential Blood Pressure	Mean systolic and diastolic blood pressure (mmHg) obtained during one week through residential blood pressure monitoring using validated devices and standardized protocols across the intervention period. Lower values indicate improvement.	Baseline and 4 weeks
Change in Resting Heart Rate	Heart rate (beats per minute) measured under resting conditions using validated device	Baseline and 4 weeks

Collaborators and Investigators

• Sponsor: University of Nove de Julho
• Investigators: Principal Investigator: Raphael Dias, PhD, University of Nove de Julho

Study record dates

Study Major Dates

• Study Start (Estimated): May 1, 2026
• Primary Completion (Estimated): August 31, 2027
• Study Completion (Estimated): November 30, 2027

Study Registration Dates

• First Submitted: April 6, 2026
• First Submitted That Met QC Criteria: April 6, 2026
• First Posted (Actual): April 13, 2026

Study Record Updates

• Last Update Posted (Actual): April 13, 2026
• Last Update Submitted That Met QC Criteria: April 6, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Blood pressure; Vascular function; Vascular Photobiomodulation
• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Hypertension
• Other Study ID Numbers: PBM-Hypertension-RCT-2026

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: We plan to share the protocol and data after the completion of the study
• IPD Sharing Time Frame: The protocol will be submitted briefly The data will be shared after the publication of the main results of the study
• IPD Sharing Access Criteria: It will be open
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP

Drug and device information, study documents

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