Glucose is removed from the blood faster when people are cold. Brown adipose tissue, which can produce heat, plays an important role in this. In an earlier study by the research group, insulin sensitivity in patients with type 2 diabetes in mild cold (14 to 15 °C for 6 hours per day) improved significantly after ten days. However, there were hardly any changes in the brown adipose tissue.
“When we’re cold, we can activate our brown fat to burn energy and release heat. In addition, the muscle can generate heat by trembling. Because humans have significantly more muscle than brown fat, shivering allows them to burn more calories and produce more heat,” said Adam Sellers of Maastricht University, who presented the results of the previously unpublished study at the annual meeting of the European Society for the Study of Diabetes.
To find out more, the researchers shivered 15 volunteers at 10°C for 1 hour each day for 10 days. As a result, their fasting blood sugar fell from 5.84 to 5.67 mmol/L and their glucose tolerance improved by 6 percent. The amount of certain blood fats – triglycerides and free fatty acids – fell by 32 and 11 percent, respectively, systolic (upper) blood pressure by about 10 and diastolic (lower) blood pressure by 7 mmHg. Heart rate at rest was also lower. “The tremors improved many factors associated with diseases like type 2 diabetes. We therefore plan to investigate the effect of tremors in adults with type 2 diabetes,” Sellers concluded.