Diabetes and obesity linked to brain changes

28th April 2017 – Overweight and obese people with type 2 diabetes may have a higher risk of progressive brain problems such as dementia compared to diabetic people who are a healthy weight, according to a study.

Researchers in South Korea and the United States looked into how being overweight or obese as well as having type 2 diabetes could affect the brain. Their research found that these people were more at risk of severe and progressive changes in their brain structure and of having impaired cognitive skills (how the brain learns and thinks) compared to normal-weight participants.

Their findings suggest that weight can have an additional impact on how type 2 diabetes affects the brain. The European Association for the Study of Diabetes published the study in their journal Diabetologia.

Diabetes, being overweight and the brain

Scientists already know that type 2 diabetes increases the risk of a range of health problems in a number of organs throughout the body. This includes the brain, where it is thought the disease may speed up cognitive impairment and increase the risk of dementia. However, scientists are unsure how type 2 diabetes alters the brain, though they think several metabolic effects play a role such as insulin resistance, poor blood sugar control and inflammation.

Obesity is already known to increase the risk of developing type 2 diabetes: people with this form of diabetes are often initially overweight. In addition, being overweight has been linked to metabolic problems, which have independently also been associated with changes in the brain that could increase the risk of dementia. However, scientists know very little about how excess weight or obesity combined with type 2 diabetes can affect the brain.

Meanwhile, there is an increase in overweight and obese people contributing to a global epidemic of type 2 diabetes. This epidemic is making it increasingly important to understand how the combined effects of being overweight or obese and having type 2 diabetes could have an impact on health, including brain structure and cognitive skills.

Dr Emily Burns, research communications manager at Diabetes UK, says: "We know Type 2 diabetes is linked to changes within the brain and may increase the risk of dementia, but we don't know exactly why. That's why research like this, shedding more light on these changes, is very important."

The study

Previous studies have recently suggested a difference in type 2 diabetes traits based on being a normal weight or being obese. The researchers of this study wanted to look at whether being overweight or obese could "influence type 2 diabetes-related brain structural changes and cognitive dysfunction".

Led by Dr Sunjung Yoon and Dr In Kyoon Lyoo at Ewha Womens University in South Korea, and Hanbyul Cho at University of Utah in the USA, researchers recruited 150 Koreans between 30 and 60 years old to take part in their study.