New research has suggested that blood sugar could play a key role in the increased risk of dementia post-stroke.
This new study has shown that loss of general thinking ability occurred at a quicker rate in stroke survivors who had high blood glucose in the years post-stroke, even after accounting for other aspects that could affect their brainpower.
Individuals whose blood pressures or cholesterol were high after their stroke did not lose points on tests of thinking ability, also known as global condition, as quickly.
The researchers also found the same results when they focused on those with a high genetic risk for dementia.
This research is based on data from the STROKE COG study, which pooled, harmonised and analysed data from four long-term studies of groups of people across four decades.
The study includes data from close to 1,000 people who had detailed measurements of brain function and blood tests taken for years before and after they had a stroke – including 781 who had two or more brain function tests in the years post-stroke. Nearly 800 of the entire group also had a gene test for the APOE4 genetic variation that is associated with high risk for Alzheimer’s disease.
First author of the study, professor Deborah A. Levine, says: “Having a stroke increases a person’s risk of dementia up to 50-fold, but we lack a comprehensive treatment approach that could reduce this risk, other than preventing a second stroke.
“These findings suggest that higher cumulative blood sugar levels after stroke contribute to faster cognitive decline, and hyperglycemia after stroke, regardless of diabetes status, could be a potential treatment target to protect post-stroke cognition.”
The researchers made adjustments with the data for differences in age, income, education, use of tobacco and alcohol, BMI, heart disease and kidney function and use of medications to treat high blood pressure, cholesterol and blood sugar.
Post-stroke blood sugar measurements were taken an average of two years after their first stroke; about 20 per cent of the study participants were taking diabetes medication before their stroke.
None of the factors were linked to a faster loss of memory or executive function, which measures complex decision-making ability.
Levine highlights that the new study suggest the necessity of clinical research to test whether tight glycemic control in stroke survivors reduce post-stroke cognitive decline and dementia in those with and without diagnosed diabetes.
Tight glycemic control has been shown in people with diabetes to reduce small blood vessel complications in the eyes, kidney and nerves. Tight glycemic control in stroke survivors reduces post-stroke cognitive decline and dementia in those with and without diagnosed diabetes.
