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

Study Overview
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Brief Summary
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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.

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

Conditions
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Sunlight Exposure

Intervention / Treatment
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* Other: Sunlight exposure


Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Intervention Model: Single Group Assignment
Interventional Model Description: Single group parallel study
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: Baseline<br>Baseline measurement | |
| Experimental: Intervention<br>Sunlight intervention | Other: Sunlight exposure<br>* 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.<br>|

What is the study measuring?
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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 |