Developing diabetes younger 'increases dementia risk'

Up to one third of the UK population may have pre-diabetes, a condition that can lead to diabetes

A diabetes sufferer prepares an insulin injection. AFP

Developing diabetes at a younger age increases the risk of dementia, new research suggests.

Research findings indicate that preventing progression from pre-diabetes to a diagnosis of Type 2 diabetes could mean a substantial reduction in future dementia cases, experts say.

Pre-diabetes is a condition where blood sugar is high but has not yet crossed the threshold for Type 2 diabetes.

It is linked with a high risk of progression to diabetes but is also independently associated with other changes in health.

Most people who develop diabetes first pass through pre-diabetes.

Among middle-aged adults with pre-diabetes, between 5 per cent and 10 per cent a year go on to develop Type 2 diabetes, with 70 per cent of those with pre-diabetes progressing to diabetes, the researchers say.

Research suggests that up to one third of the UK population may have pre-diabetes.

To look at the risk of dementia associated with pre-diabetes, the authors analysed data from people of the Atherosclerosis Risk in Communities study in the US.

According to the study there was a three times greater risk of dementia for those developing Type 2 diabetes before the age of 60.

This fell to a 73 per cent increased risk for those developing the condition aged 60-69 and a 23 per cent increased risk for those developing it at 70-79.

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The findings, published in Diabetologia, suggest that at ages 80 or older, developing diabetes was not associated with an increased risk of dementia.

“Our results suggest that aggressively managing pre-diabetes may be an important way to reduce dementia risk,” study co-author Dr Michael Fang, of Johns Hopkins Bloomberg School of Public Health, told The National.

“This is incredibly valuable given the large number of people with pre-diabetes around the world.

“Pre-diabetes currently impacts nearly 500 million adults, and this number is only set to increase."

The study by PhD student Jiaqi Hu and Prof Elizabeth Selvin of the Johns Hopkins Bloomberg school in the US, and colleagues, evaluated the association of pre-diabetes with dementia risk before and after accounting for the later development of Type 2 diabetes.

Among 11,656 people without diabetes to begin with, 2,330 (20 per cent) had pre-diabetes.

When accounting for diabetes that developed after the baseline period, the researchers found no statistically significant association between pre-diabetes and dementia.

But they found that earlier ages of progression to Type 2 diabetes had the strongest link with dementia.

“Diabetes prevention remains a major challenge across the world and more research is needed to understand how to effectively implement preventive policies and programmes,” Dr Fang said.