Are type 1 diabetes and dementia linked?

Posted on 14 September 2018

Type 1 diabetes and dementia - grey haired man and woman wearing backpacks facing away

A new study has found a link between blood glucose levels and risk of dementia in over-50s living with type 1 diabetes.

Dementia is the term used to describe a collection of symptoms associated with declining brain function.

The researchers followed over 3,000 people in the USA with type 1 diabetes for an average of six years.

People with HbA1c levels of 8% or more were more likely to develop dementia than those with lower HbA1c levels.

Why did they do this research?

Advances in treatments and technology mean that people diagnosed with type 1 diabetes are now living longer than ever. As more people live with type 1 diabetes until old age, the researchers wanted to investigate how glucose levels were linked with dementia.

The team analysed a large set of health data of over-50s living with type 1 diabetes in California, to see if HbA1c levels were linked with dementia diagnoses.

What did they find?

155 people out of the 3,433 participants developed dementia during the study period, on average at the age of 64.

People who had HbA1c levels over 8% for longer periods of time were about twice as likely to develop dementia than those with lower HbA1c levels.

In addition, dementia risk was lower the more time people spent with lower HbA1c levels of 6 -7.9%.

What does this mean for type 1?

Whilst HbA1c is not always a fully accurate reflection of blood glucose level management, these findings highlight the importance of keeping glucose levels in range.

The good news is that in their paper, the researchers say that their findings are in line with best practice guidelines:

“Currently recommended glycaemic targets for older patients with type 1 diabetes are consistent with healthy brain ageing.”

The researchers stressed however that the data they analysed wasn’t perfect, and so their results cannot be taken as conclusive evidence just yet – more research will be needed first.

What’s the next step?

The researchers highlight in their paper that more work is needed to understand why exactly blood glucose levels affect the risk of developing dementia.

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