Featured Research

from universities, journals, and other organizations

Room light before bedtime may impact sleep quality, blood pressure and diabetes risk

Date:
January 14, 2011
Source:
The Endocrine Society
Summary:
Exposure to electrical light between dusk and bedtime strongly suppresses melatonin levels and may impact physiologic processes regulated by melatonin signaling, such as sleepiness, thermoregulation, blood pressure and glucose homeostasis.

According to a recent study accepted for publication in The Endocrine Society's Journal of Clinical Endocrinology & Metabolism (JCEM), exposure to electrical light between dusk and bedtime strongly suppresses melatonin levels and may impact physiologic processes regulated by melatonin signaling, such as sleepiness, thermoregulation, blood pressure and glucose homeostasis.

Melatonin is a hormone produced at night by the pineal gland in the brain. In addition to its role in regulating the sleep-wake cycle, melatonin has been shown to lower blood pressure and body temperature and has also been explored as a treatment option for insomnia, hypertension and cancer. In modern society, people are routinely exposed to electrical lighting during evening hours to partake in work, recreational and social activities. This study sought to understand whether exposure to room light in the late evening may inhibit melatonin production.

"On a daily basis, millions of people choose to keep the lights on prior to bedtime and during the usual hours of sleep," said Joshua Gooley, PhD, of Brigham and Women's Hospital and Harvard Medical School in Boston, Mass. and lead author of the study. "Our study shows that this exposure to indoor light has a strong suppressive effect on the hormone melatonin. This could, in turn, have effects on sleep quality and the body's ability to regulate body temperature, blood pressure and glucose levels."

In this study, researchers evaluated 116 healthy volunteers aged 18-30 years who were exposed to room light or dim light in the eight hours preceding bedtime for five consecutive days. An intravenous catheter was inserted into the forearms of study participants for continuous collection of blood plasma every 30-60 minutes for melatonin measurements. Results showed exposure to room light before bedtime shortened melatonin duration by about 90 minutes when compared to dim light exposure. Furthermore, exposure to room light during the usual hours of sleep suppressed melatonin by greater than 50 percent.

"Given that chronic light suppression of melatonin has been hypothesized to increase relative risk for some types of cancer and that melatonin receptor genes have been linked to type 2 diabetes, our findings could have important health implications for shift workers who are exposed to indoor light at night over the course of many years," said Gooley. "Further research is still needed to both substantiate melatonin suppression as a significant risk factor for breast cancer and determine the mechanisms by which melatonin regulates glucose metabolism."

Other researchers working on the study include: Kyle Chamberlain of the University of Surrey in the United Kingdom; and Kurt Smith, Sat Bir Khalsa, Shantha Rajaratnam, Eliza Van Reen, Jamie Zeitzer, Charles Czeisler and Steven Lockley of Brigham and Women's Hospital and Harvard Medical School in Boston, Mass.


Story Source:

The above story is based on materials provided by The Endocrine Society. Note: Materials may be edited for content and length.


Journal Reference:

  1. Joshua Gooley et al. Exposure to room light prior to bedtime suppresses melatonin onset and shortens melatonin duration in humans. JCEM, March 2011

Cite This Page:

The Endocrine Society. "Room light before bedtime may impact sleep quality, blood pressure and diabetes risk." ScienceDaily. ScienceDaily, 14 January 2011. <www.sciencedaily.com/releases/2011/01/110113082716.htm>.
The Endocrine Society. (2011, January 14). Room light before bedtime may impact sleep quality, blood pressure and diabetes risk. ScienceDaily. Retrieved April 23, 2014 from www.sciencedaily.com/releases/2011/01/110113082716.htm
The Endocrine Society. "Room light before bedtime may impact sleep quality, blood pressure and diabetes risk." ScienceDaily. www.sciencedaily.com/releases/2011/01/110113082716.htm (accessed April 23, 2014).

Share This



More Health & Medicine News

Wednesday, April 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Big Pharma Braces for M&A Wave

Big Pharma Braces for M&A Wave

Reuters - Business Video Online (Apr. 22, 2014) Big pharma on the move as Novartis boss, Joe Jimenez, tells Reuters about plans to transform his company via an asset exchange with GSK, and Astra Zeneca shares surge on speculation that Pfizer is looking for a takeover. Joanna Partridge reports. Video provided by Reuters
Powered by NewsLook.com
How Smaller Plates And Cutlery Could Make You Feel Fuller

How Smaller Plates And Cutlery Could Make You Feel Fuller

Newsy (Apr. 22, 2014) NBC's "Today" conducted an experiment to see if changing the size of plates and utensils affects the amount individuals eat. Video provided by Newsy
Powered by NewsLook.com
How to Master Motherhood With the Best Work/Life Balance

How to Master Motherhood With the Best Work/Life Balance

TheStreet (Apr. 22, 2014) In the U.S., there are more than 11 million couples trying to conceive at any given time. From helping celebrity moms like Bethanny Frankel to ordinary soon-to-be-moms, TV personality and parenting expert, Rosie Pope, gives you the inside scoop on mastering motherhood. London-born entrepreneur Pope is the creative force behind Rosie Pope Maternity and MomPrep. She explains why being an entrepreneur offers the best life balance for her and tips for all types of moms. Video provided by TheStreet
Powered by NewsLook.com
Catching More Than Fish: Ugandan Town Crippled by AIDS

Catching More Than Fish: Ugandan Town Crippled by AIDS

AFP (Apr. 22, 2014) The village of Kasensero on the shores of Lake Victoria was where HIV-AIDS was first discovered in Uganda. Its transient population of fishermen and sex workers means the nationwide programme to combat the virus has had little impact. Duration: 02:30 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins