Researchers have long detected higher rates of dementia in people with type 2 diabetes. New findings from Imperial College London are offering clues to why that may be the case, indicating that cardiometabolic factors associated with diabetes, such as increased blood pressure, could be contributing to the development of dementia.
Some estimates have shown people with diabetes are twice a likely to develop dementia in their senior years, compared to those otherwise healthy subjects. Exactly how these two conditions are connected is still unclear.
New research recently presented at the Diabetes UK Professional Conference 2021 is offering clues to help explain the causal mechanisms that may underpin this frequently observed association. The research, yet to be peer-reviewed and published, investigated the long-term medical histories of more than 200,000 individuals with type 2 diabetes.
About 10 percent of the cohort had developed dementia so the researchers tracked the 20 years of data leading up to each subject’s dementia diagnosis. The focus was on cardiometabolic factors including changes to blood pressure and cholesterol.
The findings revealed those diabetic patients who went on to develop dementia displayed higher blood pressure up to 19 years before diagnosis, compared to those diabetic patients who did not develop dementia. Both blood sugar and cholesterol levels were also higher in diabetics who developed dementia, compared to those displaying no cognitive decline.
Eszter Vamos, who led the Imperial College London research, notes these findings cannot confirm a causal mechanism between diabetes and dementia. However, she says the research highlights the importance of diabetics closely monitoring and managing cardiometabolic symptoms.
“Our results emphasize the importance of carefully managing cardiometabolic factors such as blood pressure, cholesterol and glucose levels early on, for people with type 2 diabetes,” says Vamos. “While this study cannot confirm causal associations, these results show that blood pressure and other cardiometabolic factors could be contributing to dementia development up to two decades before diagnosis.”
An Australian study published late last year found older diabetics patients taking a drug called metformin experienced slower rates of cognitive decline compared to a matched cohort of diabetic patients not taking the medication. Metformin is currently being investigated for its potential lifespan-extending effects, so the Australian study suggested the lower rates of dementia seen in the cohort could be attributed to a novel effect of metformin.
This new research, however, suggests any effective diabetes treatment may help mitigate cognitive decline associated with the disease. Elizabeth Robertson, from Diabetes UK, says these new findings point to ways type 2 diabetes could contribute to the onset of dementia.
“Changes in the body that lead to dementia occur years before symptoms arise, and for the first time, researchers have uncovered a pattern of changes in people with type 2 diabetes that are associated with dementia,” says Robertson. “Knowing which factors contribute to the development of dementia, and when they have the biggest impact, is vital in giving people with type 2 diabetes the best possible care to prevent or delay dementia onset.”
Source: Imperial College London