Study: Dim lights in evening can reduce risk of gestational diabetes

A new study has found that the risk of gestational diabetes is reduced if pregnant women dim the lights at home during the evening and turn off or dim their screens and other devices a few hours before bedtime.

Light exposure in the three hours before sleep onset was higher among women who developed gestational diabetes mellitus in the multi-site study. They were not different from those who did not develop it in terms of how much time they spent in the dark or how active they were during the day.

The results of the study were published in the American Journal of Obstetrics and Gynecology Maternal Fetal Medicine on March 10. Dr. Minjee Kim, an assistant professor of neurology at Northwestern University's Feinberg School of Medicine and neurologist with Northwestern Medicine, was the lead author.

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Study investigates risk of gestational diabetes

A new study has found that dimming down all kinds of lights a few hours before sleep can significantly reduce risk of diabetes during pregnancy. (Image via Pexels/Daniel Reche)

Gestational diabetes is rising at an alarming rate in the United States and around the world.

This type of diabetes affected about 4.5% of first-time mothers with babies born between 2011 and 2013, and its prevalence is expected to rise by an average of 3.4% every three years through 2019. In 2020, 7.8% of all U.S. pregnancies were complicated by diabetes.

Obstetric complications and mother's risk of developing diabetes, heart disease and dementia, are known to be exacerbated by diabetes during pregnancy. The offspring also faces an increased risk of developing adult-onset obesity and hypertension.

Light exposure in the three hours before sleep onset was higher among women who developed diabetes mellitus during pregnancy in the multi-site study. They were not different from those who did not develop it in terms of how much time they spent in the dark or how active they were during the day.

Dim lighting during the evening can help your system get used to its natural circadian rhythm.(Image via Pexels/Mael Balland)

In the study, scientists suggested that light exposure before bedtime may be an under-recognized but easily modifiable risk factor for gestational diabetes.

There's mounting evidence linking late-night light exposure to abnormal glucose regulation in females who're not pregnant. Gestational diabetes is a common complication of pregnancy, but the impact of evening light exposure on risk of developing this condition is not well understood.

According to Kim's research, women who develop gestational diabetes are nearly ten times more likely to develop type 2 diabetes mellitus than women who do not have glucose issues during pregnancy.

Bright lights in your home and electronic devices like TVs, computers and smartphones can all contribute to a night of disrupted sleep. Women who have had gestational diabetes during a previous pregnancy are more likely to develop the condition again. Light exposure right before bedtime has been linked to metabolic syndrome, insulin resistance and hypertension.

Although exercise and weight loss have been shown to prevent diabetes, turning down lights in the evening is an easy lifestyle modification. (Image via Pexels/Lucas Mendes)

Light exposure before bedtime affects glucose metabolism by stimulating sympathetic overactivity, which causes the heart rate to remain elevated when it should be decreasing. It appears that the body's 'fight or flight' mechanism is sometimes triggered at rest.

Sympathetic overactivity has been linked to cardiometabolic disease, which includes but is not limited to abdominal obesity, insulin resistance, high blood pressure and a lipid imbalance that can lead to cardiovascular disease.

A total of 741 pregnant women participated in the study, which was conducted between 2011 and 2013 at eight clinical sites in the United States. An actigraph, worn on the wrist, recorded how much time the subjects were exposed to light. Women were weighed and measured during their second trimester of pregnancy, when they typically undergo screening for gestational diabetes.

Pre-sleep light exposure was independently associated with an increased risk of diabetes after further controlling for age, body mass index, race/ethnicity, education, commercial insurance, working hours, season, sleep duration and other sleep factors.

Increases in both maternal age and body mass index have been linked to the alarming rise in the prevalence of diabetes. Avoiding weight gain during pregnancy can help you avoid diabetes during pregnancy. Losing weight and exercising lower the likelihood of developing diabetes and should be included in everyone's health checklist. However, dimming the lights is a simple adjustment to make.