Some people have a greater genetic risk than others of developing type 2 diabetes. Now, more of these at-risk people are actually developing diabetes than previously.
Type 2 diabetes is often triggered by a sedentary lifestyle or poor diet. At the same time, however, some people have genes that make it much more likely they will develop the disease. In other words, they are far more susceptible to developing diabetes.
"More people with a high genetic risk of developing type 2 diabetes are now developing the disease than they did in the past," said Vera Vik Bjarkø.
Bjarkø is a PhD research fellow at the Norwegian University of Science and Technology (NTNU's) Department of Public Health and Nursing. She and her colleagues recently published an article in The Lancet Diabetes & Endocrinology.
86,000 people studied
This time, the study included data from more than 86,000 people with almost 200,000 measurements.
The data were taken from The HUNT Study (the Trøndelag Health Study), in which data collection began as early as 1984.
"We see that the difference in the prevalence of type 2 diabetes between people with high and low genetic predisposition to the disease increased from the 1980s to the 2010s," explained Bjarkø.
But why are more people with a high genetic predisposition developing type 2 diabetes than before?
"We believe it is possible to view this as closely linked to societal changes," said Bjarkø.
More temptations
We are surrounded by many more temptations than before, both when it comes to diet and sedentary leisure activities. In 1984, many Norwegians still had only one TV channel, mobile phones weighed several kilos and tablets were science fiction.
Many of us ate unhealthily then as well, but Norwegians were in no way surrounded by as many tempting and easy-access calories as today. Most people were not as well off financially either, and snacks and sweets were more often reserved for the weekend.
"Our interpretation of the findings is that people with a high genetic risk are especially vulnerable in a society that may be more conducive to developing diabetes," explained Bjarkø.
Some people may be protected
People with a high genetic predisposition are most affected, whereas for individuals with a low genetic predisposition, the prevalence of type 2 diabetes remained consistently low throughout this long period.
"It seems that people with a low genetic risk are largely protected from these kinds of factors. We simply don't know that much about exactly how our genes influence this. But it is likely that some people have strong genetic protection against diabetes. Some individuals may have a low genetic susceptibility to obesity, while others may have mechanisms that prevent them from developing diabetes even when severe obesity or other risk factors are involved," Bjarkø said.
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