Acute Effects of Whole Body Blue Light Exposure on Blood Pressure

Acute Effects of Whole Body Blue Light Exposure on Blood Pressure, Endothelial Function and Vascular Stiffness

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.

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