A new study by the Rensselaer Polytechnic Institute’s Lighting Research Center shows that exposure for two hours to back-lit electronic devices such as tablets can lead to delayed bedtimes, especially in teens, reports "Buffalo Business First" (http://macte.ch/HH8h9).

Researchers at the research center found that using devices with back-lit displays before bedtime suppressed the production of melatonin, a hormone produced by the pineal gland in dark surroundings that signals "nighttime" to the body. Melatonin suppression has been implicated in sleep disturbances and increased risk for diabetes and obesity, according to the researchers.

In the study, 13 people used tablets to read, play games and watch movies. Melatonin production was off about 22 percent, according to the researchers.

Stimulating the body’s normal circadian rhythms by that level "may affect sleep in those using the devices prior to bedtime," lead researcher Mariana Figueiro, associate professor at Rensselaer and director of the Lighting Research Center's light and health program, told "Buffalo Business First."