Immediate Effect of Light on Reproductive Hormones in Women: a Role of the Spectrum
The study investigates an acute effect of white-appearing LED light (with a peak in blue portion) vs. red LED light of similar irradiance on reproductive hormones in healthy women.
|Study Design:||Allocation: Non-Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Crossover Assignment
Masking: Single Blind (Outcomes Assessor)
Primary Purpose: Basic Science
- Reproductive hormones concentration [ Time Frame: 3 months ] [ Designated as safety issue: No ]
|Study Start Date:||March 2009|
|Study Completion Date:||October 2009|
|Primary Completion Date:||May 2009 (Final data collection date for primary outcome measure)|
Sixteen healthy women came to the laboratory at 7:30 (wearing dark goggles) at two occasions (separated by 2-3 days, first time - at the 3rd-8th day of their menstrual cycle) to be exposed for 45' to white-appearing or red LED light (sequential allocation). The white light has a distinct peak at 460 nm, the narrow-band red light peaked at 651 nm. The LED devices were positioned at the distance of 50 cm (white) and 45 cm (red) from the eyes to be matched by irradiance (approximately 7.0 microWt/m2); background light in direction of gaze was 5-10 lux. Blood and saliva samples were collected before, in the middle, and during the last minutes of the 45' exposure to be measured later for concentration of luteinizing hormone, follicle-stimulating hormone, prolactin, estrogen, progesterone, and also - for cortisol and melatonin (the last one - in saliva) as well-studied indicators of the direct effect of light.
|Institute of Internal Medicine SB RAMS|
|Novosibirsk, Russian Federation, 630089|
|Study Chair:||Konstantin V Danilenko, MD||Institute of Internal Medicine SB RAMS|
|Principal Investigator:||Oksana Y. Sergeeva, PhD student||Institute of Internal Medicine SB RAMS|