Female jogger wears diabetes glucose monitorShare on Pinterest
A new study suggests that young adults with diabetes may have a higher risk of developing Alzheimer’s disease. Courtney Hale/Getty Images
  • A new study suggests that early-onset diabetes may increase the risk of Alzheimer’s disease.
  • Although the study is small, the results line up with previous findings.
  • Controlling diabetes with lifestyle changes or medication may help lower dementia risk.

New research investigates links between early-onset diabetes and future Alzheimer’s risk.

The authors found that young adults with diabetes — both type 1 and type 2 — have blood markers associated with the development of Alzheimer’s disease, whereas young adults without diabetes did not. The findings were published May 6 in the journal Endocrines.

The researchers note that due to the small sample size of the study, further investigation is needed.

“We are about to enter into a different world of healthcare because of the obesity epidemic in young people,” Allison Shapiro, PhD, assistant professor of pediatrics and endocrinology at the University of Colorado School of Medicine in Aurora, said in a news release.

“Young people are catching up with adults. We are now seeing more aging-related diseases in young people. We are not saying these people have [Alzheimer’s disease] or have cognitive impairment,” she continues, “we are saying that this trajectory is concerning.”

Is there a correlation between diabetes and Alzheimer’s?

Scientists have already carried out a fair amount of research investigating potential links between diabetes and thinking, or cognitive skills.

Research has shown that people with diabetes are twice as likely to experience cognitive dysfunction than people without diabetes.

Similarly, people with type 2 diabetes have a higher risk of developing Alzheimer’s than people without diabetes.

According to the authors of the present study, individuals with diabetes “have a 60–80% greater likelihood” of developing Alzheimer’s disease.

The scientists accessed data from 25 people with type 1 diabetes and 25 with type 2 diabetes. They compared blood biomarkers with a similar number of control participants without diabetes.

They measured a range of biomarkers linked to neurodegeneration and the buildup of proteins associated with Alzheimer’s. Some participants also underwent positron emission tomography (PET) scans to look for early signs of the disease in the brain.

Their analysis showed that markers indicating Alzheimer’s progression were higher in those with early-onset diabetes than the controls. Also, the markers for Alzheimer’s were more pronounced in young adulthood than in adolescence.

Although these links are fairly well established, there is very little research into the relationship between early-onset diabetes — in childhood, adolescence, and early adulthood — and later Alzheimer’s risk.

Early-onset diabetes on the rise

In the United States and elsewhere, type 2 diabetes most often starts after the age of 50, but this is changing.

Research shows that youths are increasingly likely to develop both type 1 and type 2 diabetes. Between 2002 and 2012, type 1 diabetes in youths increased by 1.4% per year. Type 2 diabetes in youths increased 7.1% each year — a steep rise.

Along similar lines, a study published earlier this year found that around half of people with type 2 diabetes now develop it before the age of 50.

However, there has been little research into how early-onset diabetes impacts future Alzheimer’s risk.

One study from the United Kingdom does show that people who develop type 2 diabetes at a younger-than-average age have a higher risk of dementia, but the participants in this study were 35 or older.

So, the latest study investigates the relationship between diabetes and Alzheimer’s risk in youths and young adults.

This is important because, as the authors explain, individuals with early-onset diabetes often have the condition for decades longer than people who develop it at the average age.

Understanding how this extended disease course impacts later life could be a vital window into the future health of the U.S. population.

Why would diabetes cause Alzheimer’s?

Although Alzheimer’s and diabetes seem unrelated, scientists have identified a number of metabolic links.

People with diabetes either produce too little insulin or their cells do not respond as well to insulin, which is called insulin resistance.

Because insulin helps move sugar (glucose) from the bloodstream if insulin cannot carry out its work, blood sugar levels remain high, which can cause damage to the body’s tissues.

While insulin resistance occurs in the muscles, fat, and livers of people with diabetes, it also occurs in the brains of people with Alzheimer’s.

In fact, some scientists believe that insulin resistance in the brain might be the driving force behind Alzheimer’s, leading some researchers to call Alzheimer’s “type 3 diabetes.”

Vasileios Papaliagkas, MD, PhD, an associate professor of physiology at the International Hellenic University in Greece, not involved in the study, explained the similarities between the two conditions.

He told Healthline how, in Alzheimer’s, a protein called amyloid beta builds up and clumps together in the brain. “Amyloid beta […] is also observed in the pancreas of patients with type 2 diabetes,” he said.

According to Papaliagkas, there are other similarities between the two conditions: Both are linked with inflammation in the brain, oxidative stress, and a buildup of advanced glycation end products.

Advanced glycation end products are fats or proteins that are modified by sugar. They play a role in the development of atherosclerosis, where arteries become narrow, increasing the risk of conditions like heart attack and stroke.

Can treating diabetes help reduce dementia risk?

Although these results are preliminary, the next steps for this research could be to explore whether diabetes treatment could help reduce the risk of dementia.

Some research does suggest that the dementia risk is higher for people with untreated type 2 diabetes than for those with well-managed diabetes.

Papaliagkas told Healthline that “controlling and treating diabetes will reduce the risk of dementia in later life.”

Other scientists believe that diabetes medication may even help treat Alzheimer’s disease in people without diabetes.

While scientists need to carry out more research on the links between early-onset diabetes and Alzheimer’s, this is a good start.

“Understanding more about the biological processes that link longer duration of diabetes to changes in brain health is vital for the development of new treatments to help people with diabetes live long and healthy lives,” Lucy Chambers, PhD, head of research communications at Diabetes UK, not involved in the study, told Healthline.

Takeaway

Diabetes in adulthood is linked to an increased risk of Alzheimer’s later in life. A new study finds markers of Alzheimer’s in the blood of people with early-onset diabetes, suggesting they also have elevated risk.

Diabetes management could help minimize the risk of Alzheimer’s, but further studies are needed to fully understand this association.