Clinical Research Office. A partnership between Sheffield Teaching Hospitals NHS Foundation Trust and the University of Sheffield

Research sheds new light on impact of diabetes on the brain

RESEARCHERS from Sheffield Teaching Hospitals NHS Foundation Trust and the University of Sheffield have discovered that diabetic nerve damage causes more harm in the brain than previously thought, shedding new light on the disease.

New findings published in the Diabetes Care journal reveal the extent of damage patients suffering with the disease can endure in areas of the brain called ‘grey matter’ – a key component of the central nervous system which is involved in touch and pain sensory perception.

During the study, which involved patients with Type 1 and Type 2 diabetes, researchers used recent advances in brain imaging and analyses methods to take detailed nerve assessments of the brain using magnetic resonance imaging (MRI) techniques. This revealed that the volume of certain brain regions in people with diabetic neuropathy was significantly lower compared to those without the disease.

Previous studies have shown that the impact of the disease on the brain is limited and isolated to outside areas of the brain considered to be peripheral to core functions in the body.

The breakthrough could pave the way for better assessment and monitoring of the disease, which affects around a third of people with diabetes. This, in turn, could lead to better treatments for sufferers in the future.

Diabetic neuropathy is a common complication of Type 1 and Type 2 diabetes, affecting up to a third of all patients with the disease, and causing distressing pain in the feet and legs which is often unresponsive to medical treatments. It is the main initiating factor for diabetic foot ulceration – the most common reason people with diabetes end up staying in hospital for a lengthy period of time. It is also the most common cause of non-traumatic lower limb amputations, impaired balance and posture.

The research was conducted by Dr Dinesh Selvarajah, a Senior Lecturer and Honorary Consultant in diabetes at the Royal Hallamshire Hospital and a team from Sheffield Teaching Hospitals NHS Foundation Trust (led by Professor Solomon Tesfaye) and the University of Sheffield (led by Professor Iain Wilkinson). The research was funded by JDRF, the leading global funder of Type 1 diabetes research.

Professor Solomon Tesfaye, of the Royal Hallamshire Hospital and the principal investigator of the study, said: “For decades diabetic neuropathy was considered a disease that affects the peripheral nerves only, but this study has shown the impact of the disease also extends to involve the brain, opening a whole new area for further research aimed at effective treatments for this disabling disease.”

Dr Dinesh Selvarajah, of the Royal Hallamshire Hospital, said: “Diabetic nerve damage has a massive impact on the quality of people’s lives, physically, mentally and socially. With the number of people suffering from diabetes around the world soaring, these are significant findings. Our study reveals for the first time how extensively involved diabetic neuropathy is in the brain, causing shrinking and a reduction in the main part of the brain associated with sensation. This is a new insight which will go a long way towards helping us better understand, treat and prevent a disease which we thought to be fairly innocuous in terms of effects on the brain.

“The next steps will be for us to investigate at what stage this occurs, what the consequences of this are and whether it can be prevented as it could be impacting on patients’ behaviour and psychology.”

Iain Wilkinson, an MR Physics Professor within Academic Radiology at the University of Sheffield and an Honorary Consultant Clinical Scientist for Sheffield Teaching Hospitals NHS Foundation Trust, said: “To see leading-edge MRI technology pinpoint changes that might play an influential factor in the quality of so many lives highlights the need for clinical research like this. It’s such an important part of our Teaching Hospital and University.”

The grey matter region identified is a major component of the central nervous system, consisting of brain cells (or neurons) which process information from sensory organs in order to decide and execute functions. Loss of nerve cells in the grey matter, more properly known as cerebral atrophy, is highly undesirable as the functions of that area of the brain can become impaired.

The study was supported by a $486,000 grant from JDRF, awarded to Professor Solomon Tesfaye, Consultant Diabetologist and Honorary Professor of Diabetic Medicine at the University of Sheffield, and a team of colleagues from Sheffield Teaching Hospitals NHS Foundation Trust and the University of Sheffield.

According to recent figures, the number of people suffering with diabetes is expected to hit an all-time UK high by 2025, soaring to five million cases.

ENDS