Blue Light
Conditions
Keywords
blue light, blood pressure, vascular function, endothelial function, health volunteers
Brief summary
Ultraviolet light exposure was shown to be able to release nitric oxide from the skin into the blood stream and lead to an acute decrease in blood pressure and increase in vascular function. Additionally, preliminary work indicates that UV free blue light also releases nitric oxide in the skin mediating similar effects as seen with ultraviolet light A(UVA). It is the goal of the present experimental study to investigate the hemodynamic effects of whole body blue light exposure including blood pressure, endothelial function and vascular stiffness. Therefore, healthy volunteers will be exposed to 30 minutes whole body blue light (453 nm wavelength) and the change in blood pressure and endothelial function (Flow mediated dilation (FMD)), heart rate, forearm-blood flow, forearm vascular resistance central blood pressure and vascular stiffness ( pulse wave analysis by sphygmocor) will be measured. In this randomized controlled cross-over study, 20 healthy subjects aged 30 to 60 years will participate.
Interventions
PROCEDUREBlue light
Subjects will be exposed to blue light (453 nm wavelength) for 30 minutes
PROCEDUREcontrol exposure
Subjects will get control exposure to 30 minutes of whole body, which causes only comparable warming of skin as with blue light exposure.
Sponsors
Philips GmbH, Innovative Technologies, Aachen
Klinik für Unfall - und Handchirurgie, Universitätsklinikum Düsseldorf
Heinrich-Heine University, Duesseldorf
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Investigator)
Eligibility
Sex/Gender
MALE
Age
30 Years to 60 Years
Healthy volunteers
Yes
Inclusion criteria
* healthy, male subjects * age between 30 and 60 years * signed patient informed consent
Exclusion criteria
* diabetes mellitus * acute inflammation (CRP \>0.5mg/dl) * cardiac arrythmia * active cancer * renal failure * heart failure (NYHA II-IV) * arterial hypotension (systolic pressure \<100 mmHg) * treatment with antihypertensive drugs * dermatosis of the eyelid * porphyria or hypersensitivity to porphyrins * congenital or aсquired immune deficiency * genetic conditions that cause an increased sensitivity to light or an increased risk to dermatological cancer (such as xeroderma pigmentosum, cockayne syndrome, bloom syndrome) * previous intake or use of photosensitizing drugs, food or cosmetics (e.g. psychiatric medication, antibiotics, cardiovascular drugs, hormone, Hypericum, Bergamot orange) or use of perfumes
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change of peripheral blood pressure | baseline, during 30 min exposure and 2 hours thereafter | Change of peripheral blood pressure as measured before, during and up to 2 hours after 30 min blue light as compared to control |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in endothelial function | baseline, during 30 min exposure and 2 hours thereafter | measured by flow mediated dilation (FMD) before, immediately after 30 min exposure and at 2 h thereafter |
| Change from baseline heart rate | baseline, during 30 min exposure and 2 hours thereafter | measured by electrocardiography (ECG) before, during and up to 2 hours after 30 min blue light as compared to control |
| Change from baseline forearm blood flow | baseline, during 30 min exposure and 2 hours thereafter | measured by ultrasound before, immediately after 30 min exposure and at 2 h thereafter |
| Change from baseline central blood pressure | baseline, during 30 min exposure and 2 hours thereafter | measured by applanation tonometry before, immediately after 30 min exposure and at 2 h thereafter |
| Change from baseline forearm vascular resistance | baseline, during 30 min exposure and 2 hours thereafter | measured by ultrasound before, immediately after 30 min exposure and at 2 h thereafter |
| Change from baseline NO-species | baseline, during 30 min exposure and 2 hours thereafter | determined by chemiluminescence before, immediately after 30 min exposure and at 2 h thereafter |
| Change from baseline Cortisol | baseline, during 30 min exposure and 2 hours thereafter | measured before, immediately after 30 min exposure and at 2 h thereafter |
| Change from baseline Endorphins | baseline, during 30 min exposure and 2 hours thereafter | measured before, immediately after 30 min exposure and at 2 h thereafter |
| Change from baseline vascular stiffness | baseline, during 30 min exposure and 2 hours thereafter | measured by applanation tonometry before, immediately after 30 min exposure and at 2 h thereafter |
Countries
Germany
Outcome results
None listed