New research presented at this year’s European Association for the Study of Diabetes (EASD) annual meeting in Stockholm, Sweden concludes that Repeated cold exposure improves glucose tolerancelowers fasting blood sugar and fat levels, and Significantly lowers blood pressure in overweight and obese adults.
A preliminary study by Adam Sellers, Stan van Beek and their colleagues at Maastricht University in the Netherlands highlights the possibility of repeated cold exposure. Activated chills as an alternative strategy for the treatment and prevention of type 2 diabetes (T2D).
Previous research has shown that when humans are cold, glucose is cleared from the blood more rapidly. Brown fat is believed to play an important role in lowering blood sugar and improving insulin sensitivity in humans, helping to reduce the risk of disease, including insulin resistance and diabetes.
“Brown fat is a metabolic heating system within our body, which burns calories Seller explains. This generates heat and prevents calories from being stored as normal white fat. Brown fat is activated in cold weather and when we eat, but its activity is less in older adults and individuals with obesity and diabetes.”
A previous study showed that 10 days of adaptation to mild cold (14 to 15 °C, 6 hours per day) significantly improved insulin sensitivity in T2D patients. But the change in brown fat after adaptation to cold was small and could not explain the large improvement in insulin sensitivity. However, after adaptation to cold, the translocation of glucose transporter 4 (GLUT4) to skeletal muscle increased (during which GLUT4 shifts to a more favorable position that facilitates the removal of glucose from the blood into the muscle).
But while non-shivering thermogenesis – which generates heat from stored energy without muscle contraction – is implicated in adaptation to mild cold, a follow-up study suggested that some level of (mild) activating beneficial metabolic effects Muscle activity/tremor may be significant. Why cold?
“When we’re cold, we can activate our brown fat because it burns energy and releases heat to protect us. In addition, the muscle can mechanically contract, or quiver, thus producing heat. Since humans have significantly more muscle than brown fat, shivering can burn more calories and generate more heat,” explains Seller.
To learn more, researchers exposed volunteers — 11 men and 4 postmenopausal women who were overweight or obese (ages 40 to 75, with BMI 27 to 35 kg/m2) — to trigger tremors. Using cold for 10 consecutive days a suit with a splash of water to regulate and lower body temperature. Participants were exposed to cold temperatures of 32 °C to 10 °C until they shivered for one hour a day.
The cold is monitored by special devices placed on the skin that detect electrical muscle activity, as well as visual observation. when the cold weather started Resting energy expenditure increased by 50%.
Before and after the intervention, a 2-hour oral glucose tolerance test (OGTT) was performed under conditions of thermoneutrality, that is, at an environmental temperature in which the body does not need to generate heat to maintain its core temperature Is. Researchers also measured heart rate and blood pressure and took muscle biopsies to determine possible changes in muscle related to glucose metabolism, such as GLUT4 translocations.
The results showed that repeated cold-induced shivering reduced the mean fasting plasma glucose concentration from 5.84 to 5.67 mmol/L, and increased glucose tolerance by 6%.
Plasma insulin concentrations before and during POTG were unaffected after the tremor intervention. This suggests that the improvement in fasting glucose and glucose tolerance after repeated shivering was not due to an increase in blood insulin.
Interestingly, fasting plasma concentrations of triglycerides and free fatty acids were decreased by 32% and 11%, respectively. These are the body’s main fatty fuels and are believed to increase the risk of heart disease and contribute to insulin resistance.
In addition, repeated cold exposure decreased systolic and diastolic blood pressure by approximately 10 mmHg and 7 mmHg, respectively, and tended to decrease resting heart rate when measured under thermoneutral conditions.
Surprisingly, the translation of GLUT4 into muscles was unchanged after the shivering intervention. This suggests that there have been other changes in skeletal muscle and/or possibly other organs that are responsible for the improved glucose tolerance.
The authors acknowledge several limitations, including the inability to draw strong causal conclusions about the direct effect of cold exposure on metabolic health. They also point out that despite measures taken to control for diet and physical activity, other lifestyle or genetic factors not measured in the present study may have influenced the results.
“However, this is an important first step in investigating the effects of shivering on health. “Our findings are promising and may have important health implications, given that shivering improves many cardiometabolic health outcomes that are associated with diseases such as type 2 diabetes,” Sellers said. In future studies, we plan to assess the effect of tremor in adults with type 2 diabetes.”