Risk of cognitive deficits due to oxidative stress in type 2 diabetes

PATIENTS with type 2 diabetes may be at higher risk of cognitive deficits, with greater duration of the disease being associated with neurodegeneration, according to new Australian research.

Data presented at the ANZSGM conference showed that patients with type 2 diabetes were likely to have a greater number of infarcts and smaller hippocampal and grey matter volumes on MRI compared to people without diabetes.

In addition, neuropsychological testing showed that type 2 diabetes was associated with poorer visuospatial function and planning function, the conference was told. 

The reduction in brain volume could be partially due to oxidative distress, said research leader Associate Professor Velandai Srikanth, the head of the vascular brain ageing division of stroke and ageing research at Monash Medical Centre.

“Type 2 diabetes is a condition where there’s a lot of oxidative distress and inflammation going on in several parts of the body,” he said. 

“Another possibility is that [type 2 diabetes] somehow causes damage to very small blood vessels or the blood supply to the brain itself.”

The study looked at a sample of 339 people with type 2 diabetes and 373 people without diabetes drawn from the population. 

Professor Srikanth said while there has been similar research, his unpublished study presented at the conference was the first to show that the brain atrophy that occurs in diabetes was likely to be more responsible for the cognitive problems in diabetes than were vascular lesions in the brain.

He advised GPs to have a heightened awareness that patients with type 2 diabetes may be at greater risk of developing cognitive problems although no specific advice could be given until more was known about the association.

Previous studies have linked type 1 diabetes to cognitive problems, although this was likely due to episodes of hypoglycaemia, he said.