Effect of Short-term Sunlight Exposure on Blood Pressure and Pulse Rate in Vitamin D3 Insufficient, Prehypertensive Patients

A three-period parallel (baseline, treatment, and post-treatment) design clinical research was conducted. All participants visited a clinical trial center of Korea University Anam Hospital for baseline measurement of clinical variables including ABPM and hematologic biomarkers (ACTH, aldosterone, norepinephrine, cortisol, and 25-hydroxyvitamin D3). After the baseline assessment, participants visited 'Cholipo beach' (Taean, Republic of Korea) for 3 nights and 4 days for the intervention (sunlight exposure program). After a week of wash-out period, post-treatment measurement was processed at Korea University Anam Hospital. Participants were prohibited from vigorous physical activity, alcohol drinking, and smoking during the study period. A normal-sodium diet (2800 mg/day)[14], caffeine and smoking restriction was suggested during the whole study period. To control the effect of circadian rhythm on endocrine blood tests and ABPM, we fixed sampling and monitoring start time at 10:00 am. All participants received the same measurements as they did in the baseline measurement during treatment and post-treatment periods.

Study Overview

• Status: Completed
• Conditions: Sunlight Exposure
• Intervention / Treatment: Other: Sunlight exposure

• Study Type: Interventional
• Enrollment (Actual): 20
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Korea, Republic of
  • Seoul, Korea, Republic of
    • Korea University Anam Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years to 45 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• prehypertensive patients
• vitamin D insufficiency
• age 20-45

Exclusion Criteria:

• medical comorbidity other than prehypertension
• participant using medication
• Subjects with a history of cardiovascular, renal, hepatic, gastrointestinal, hematologic, psychological, or gastrointestinal abnormalities, taking any kind of medications

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: Baseline; Baseline measurement
Experimental: Intervention; Sunlight intervention	Other: Sunlight exposure; The weather was sunny and found suitable for outside activity and sunlight exposure program, with a mean temperature of 27.0-28.5 °C, the humidity of 64-80%, and global solar exposure of 1.28 to 2.99 MJ/m2 during treatment.[15] Participants were asked to lie on the beach for 45 minutes per day between 2 to 3 pm to avoid extreme skin irritation and sunburn from direct sunlight exposure.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Blood pressure	24 hour ambulatory blood pressure monitoring	24 hours
pulse rate		24 hours

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Weight	Weight in kilograms	3 weeks
Height	Height in meters	3 weeks
Age	Age in years	3 weeks
25-hydroxyvitamin D3	ng/mL	3 weeks
Aldosterone	ng/mL	3 weeks
Norepinephrine	pg/mL	3 weeks
ACTH	pg/mL	3 weeks

Collaborators and Investigators

• Sponsor: Korea University Anam Hospital

Study record dates

Study Major Dates

• Study Start (Actual): June 1, 2018
• Primary Completion (Actual): June 14, 2018
• Study Completion (Actual): June 21, 2019

Study Registration Dates

• First Submitted: May 4, 2020
• First Submitted That Met QC Criteria: May 18, 2020
• First Posted (Actual): May 19, 2020

Study Record Updates

• Last Update Posted (Actual): May 19, 2020
• Last Update Submitted That Met QC Criteria: May 18, 2020
• Last Verified: May 1, 2020

More Information

Terms related to this study

• Other Study ID Numbers: 2018AN0153

Drug and device information, study documents

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