More research needed
“We advise caution against causal interpretation of the findings and call for further studies involving direct measurement of individual exposure to light at night,” the researchers conclude.
Dr. Nye agreed.
“One issue with this study is that the areas with the highest outdoor artificial light levels are likely to be those in urban areas and bigger cities. It has been known for a long time now that living in an urbanized area increases your risk of obesity through increased access to high-fat and convenience food, less physical activity levels due to transport links, and less social activities. The authors also state this and the fact participants tended to be older,” he noted.
Large datasets are used in this investigation, however, which generally increases the reliability of the data, he observed.
But it is also “unclear as to whether the population here was selected for this study or was retrospectively analyzed, which poses reliability issues, as does the selection of the representative sample, as it is not discussed,” he noted.
Ultimately, there is no confirmed evidence of the link, and until further work is done to directly link light exposure and diabetes in humans, “the link will remain an association only,” he concluded.
A version of this article first appeared on Medscape.com.