According to American academics, turning off smartphones and dimming the lights just before going to sleep could reduce the risk of gestational diabetes in pregnant women.
Gestational diabetes, a form of diabetes that develops during pregnancy, affects about five percent of women who are expecting a baby.
Most have normal pregnancies and return to normal after delivery, but the condition has been linked to preterm birth and unusually large babies, and a higher risk of type 2 diabetes for women later in life.
A study now suggests that women who are more exposed to light in the three hours before falling asleep are at greater risk of developing gestational diabetes.
Researchers looked at 741 women in their second trimester of pregnancy whose light exposure was measured for seven consecutive days with a tracker worn on the wrist.
American researchers looked at 741 women in the second trimester of pregnancy, whose exposure to light was measured for seven consecutive days with a tracker worn on the wrist. Scientists divided women into three groups, based on how much light above 10 lux they were exposed to
The study aimed to see how many of the three hours before bed women spent in normal, brighter light — measured above the 10 lux light intensity measurement.
The trackers also measured time spent in dim lighting, less than 10 lux, which is about the level of candlelight, and can be achieved with a dim ceiling or table lamp.
Researchers divided women into three groups, based on how much light above 10 lux they were exposed to.
The women who were exposed to the most normal light for an average of one hour and 19 minutes in the three hours before bed were about five and a half times more likely to develop gestational diabetes.
This was compared to the pregnant women who got the least normal light – only about 24 minutes in the three hours before bed.
The study has limitations, as it only recorded one week of women’s exposure to light during pregnancy, which may not have been typical.
There is more evidence for a link between light exposure and diabetes in people who are not pregnant, so much more evidence is needed.”
But the authors conclude that people should limit the light they are exposed to before bed, including from electronic devices.
Dr. Minjee Kim, the neurologist who led the study from Northwestern University in the US, said: ‘We don’t think about the potential harm of keeping the environment clear from the moment we wake up until we go to bed.
“But before we go to bed, it should be pretty dark for a few hours.
“We probably don’t need that much light for everything we routinely do in the evening.”
She advised, “Try reducing the light in your environment in those three hours before you go to bed.
‘It is best not to use your computer or telephone during this period.
“But if you must use them, keep the screens as dark as possible.”
Most electronic devices have settings to limit the blue light they emit, which affects melatonin – the hormone that helps the body know when to sleep and wake up.
Melatonin is also linked to how well the body regulates blood sugar levels, which could explain how late night light may be linked to gestational diabetes during pregnancy.
The study identified a third group of women with moderate exposure to brighter light, who received about 48 minutes of normal, undimmed light in the three hours before going to bed.
Compared to the group with the least normal exposure to light, which received 24 minutes of it, women with moderate exposure were about four times more likely to develop gestational diabetes.
A total of 31 women in the group, or about four percent, developed gestational diabetes during pregnancy.
They did not differ in their daytime light exposure, or their level of exercise, compared to those who did not develop it.
But even when factors such as their age and weight were taken into account, women’s risk of gestational diabetes was higher if they had more light exposure before bed.
The research has been published in American Journal of Obstetrics and Gynecology Maternal Fetal Medicine.
Dr. Kim said: ‘Still, regular exercise and a healthy diet are among the most important things women can do to reduce their risk of gestational diabetes.
“But dimming the lights is also an easy adjustment you can make.”
What is Gestational Diabetes?
Gestational diabetes is a form of diabetes that affects pregnant women, usually during the second or third trimester.
Women with gestational diabetes do not have diabetes before pregnancy. Usually it goes away after birth.
It occurs when the hormones produced during pregnancy make it difficult for your body to use insulin properly, putting you at risk for insulin resistance.
Treatment focuses on controlling blood sugar through diet, exercise, and sometimes medication.
Women can significantly reduce their risk of gestational diabetes by managing their weight, eating a healthy diet, and staying active.
Figures estimate that one in five women develop gestational diabetes during pregnancy.
Source: Diabetes UK