As climate change raises temperatures around the world, the number of diabetes cases is also increasing.  A new study says these two conditions are linked.

The study in the journal BMJ Open Diabetes Research and Care doesn't say why rising temperatures resulted in rising cases of diabetes.  Some researchers suspect that reason is that in warmer temperatures, the human body doesn't make enough brown fat or brown adipose tissue (BAT) which it relies on to stay warm in cooler temperatures.  Healthy adult humans have significant depots of metabolically active BAT, which helps it expend energy.

"Our data are consistent with the hypothesis that a decrease in BAT activity with increasing environmental temperature may deteriorate glucose metabolism and increase the incidence of diabetes," the study authors wrote.

The authors analyzed data regarding the number of diabetes diagnoses issued between 1996 and 2013 and found the number of diabetics rose by 3.1 per 10,000 people as the average temperature rose by 1 degree Celsius.  But they also found instances of obesity wherever climate change was prevalent.  When temperatures rose 1 degree Celsius, obesity, a risk factor for Type 2 diabetes, increased by 0.173 percent.  After zeroing in on the prevalence of obesity in each state in the US, researchers found the number of diabetes cases increased by 2.9 additional cases per 10,000 people with each 1 degree temperature increase.

The new study appears to support previous research which said that exposing diabetes patients to cold conditions could increase BAT mass and activity.