title: Immediate effect of blue-enhanced light on reproductive hormones in women.
abstract: OBJECTIVE
  Light is known to stimulate reproductive function in women. We here investigated the immediate effect of light on reproductive hormones, addressing the role of blue-sensitive (~480 nm) melanopsin-based photoreception mediating the non-visual effects of light.
  
  
  METHODS
  Sixteen healthy women attended the Institute at ~07:25 (shortly after waking; sunglasses worn) twice in 2-3 days in April-May, within days 4-10 of their menstrual cycle. During one session, a broad-spectrum white-appearing light with a superimposed peak at 469 nm was presented against 5-10 lux background; during the other session, short-spectrum red light peaked at 651 nm with similar irradiance level (~7.0 W/m², corresponds to ~1200 lux) was used. Venous blood was taken at 0, 22 and 44 minutes of light exposure to measure concentrations of follicle-stimulating hormone (FSH), luteinising hormone (LH), prolactin, estradiol, progesterone and cortisol, and saliva was sampled to measure melatonin as a recognised indicator of the spectral-specific action of light.
  
  
  RESULTS
  Melatonin values, as expected, were lower with white vs. red light (p=0.014), with the greatest difference at 22 minutes. Of the other hormones, only FSH concentrations differed significantly: they were mildly higher at white vs. red light (again, at 22 minutes; p=0.030; statistical analysis adjusted for menstrual cycle day and posture change [pre-sampling time seated]).
  
  
  CONCLUSIONS
  Moderately bright blue-enhanced white light, compared to matched-by-irradiance red light, transiently (within 22 minutes) and mildly stimulated morning secretion of follicle-stimulating hormone in women in mid-to-late follicular phase of their menstrual cycle suggesting a direct functional link between the light and reproductive system.
authors: Institute of Physiology and Basic Medicine, Siberian Branch under the Russian Academy of Medical Sciences, Novosibirsk, Russia.
authors: Konstantin V
authors: KV
authors: Danilenko
authors: Institute of Internal and Preventive Medicine, Siberian Branch under the Russian Academy of Medical Sciences, Novosibirsk, Russia.
authors: Oksana Y
authors: OY
authors: Sergeeva
mesh_terms: D000328:Adult; D004958:Estradiol / Q000097:blood; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood*; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D008027:Light; D007986:Luteinizing Hormone / Q000097:blood; D008550:Melatonin / Q000378:metabolism*; D008597:Menstrual Cycle / Q000097:blood*; D011374:Progesterone / Q000097:blood; D011388:Prolactin / Q000097:blood; D055815:Young Adult
chemical_list: D011374:Progesterone; D004958:Estradiol; D011388:Prolactin; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D008550:Melatonin; D006854:Hydrocortisone