More Years With Type 2 Diabetes, Higher Dementia Risk
THURSDAY, April 29, 2021 (HealthDay News) – The younger people are when they develop type 2 diabetes, the higher their risk of dementia later in life, suggests a new study.
Many studies have found links between diabetes and a higher risk of dementia. Experts say it’s probably because diabetes can harm the brain in a number of ways.
Now, the new findings suggest that younger people with diabetes may be particularly at risk later on.
At 70, the study found that people who were recently diagnosed with type 2 diabetes did not have a greater risk of dementia than those without diabetes. The situation was different for people diagnosed more than 10 years earlier: they had double the risk of dementia, compared to people without diabetes their age.
Maybe it’s just because they’ve been living with diabetes for years.
“A younger age at onset of diabetes implies a longer duration, which allows any side effects of diabetes to develop over a longer period,” said lead researcher Archana Singh-Manoux. She is a professor-researcher at the University of Paris and at the French national health institute INSERM.
Type 2 diabetes occurs when the body loses sensitivity to insulin, a hormone that regulates blood sugar. This causes chronic high blood sugar, which over time can damage large and small blood vessels throughout the body.
These effects, which can alter blood flow to the brain, are one of the reasons diabetes is linked to dementia, Singh-Manoux said.
She also pointed out other potential pathways: Insulin plays a role in brain function, and diabetes can prevent it from doing its job. Meanwhile, treating diabetes can cause frequent episodes of hypoglycemia, which over long periods of time can also harm the brain, Singh-Manoux said.
The results, published on April 27 in the Journal of the American Medical Association, have broad implications for public health.
In the United States alone, more than 34 million people have diabetes, the vast majority being type 2, according to the American Diabetes Association.
At one time, type 2 diabetes was a disease of the elderly. But with the ever increasing prevalence of obesity – a major risk factor for type 2 diabetes – the disease is increasingly being diagnosed in young people.
“The prevalence of diabetes continues to increase,” Singh-Manoux said, “and the age of onset is getting younger and younger”.
This means that more people will live longer with diabetes and be vulnerable to complications from the disease. It is already known that the younger people are when diabetes occurs, the higher their risk of heart disease, stroke and premature death, Singh-Manoux said.
This study adds dementia to that list, she said.
The research looked at over 10,000 adults in the UK who were originally aged 35 to 55 in the 1980s. Over the next three decades, 1,710 people developed type 2 diabetes, while 639 developed. been diagnosed with dementia.
By age 70, people who had developed diabetes in the past five years were no more at risk for dementia than people without diabetes.
But those who had been diagnosed more than 10 years ago showed a doubling of their risk of dementia. Their actual rate of brain disease was 18 cases per 1,000 people each year, compared to about 9 cases per 1,000 in adults without diabetes.
Overall, the risk of dementia at age 70 increased by 24% every five years that people with diabetes lived.
This is not a surprising finding, according to Dr. Medha Munshi, who heads the Geriatric Diabetes Program at Joslin Diabetes Center in Boston.
On the flip side, Munshi said, there is “some reassurance” in the lack of additional risk in older people more recently diagnosed with diabetes.
The question is, can younger diabetic patients reduce their risk of dementia by achieving better blood sugar control?
Other studies, Singh-Manoux said, have shown that people with well-controlled diabetes have slower mental decline than those with poor control. And in that study, she noted, the risk of dementia was especially high in diabetic patients who also developed heart disease.
What is essential, said Munshi, is that prevention starts early.
“People in their 40s and 50s are generally not concerned about dementia,” she said. “But now is the time to try to prevent it.”
Controlling diabetes often means taking medication or insulin, along with diet changes and regular physical activity – which, Munshi noted, can have many long-term health benefits.
“What we do at a younger and middle age will change the way we find ourselves older,” she said.
The American Diabetes Association has more information on managing type 2 diabetes.
SOURCES: Archana Singh-Manoux, PhD, research professor, University of Paris, INSERM, Paris; Medha Munshi, MD, director, Geriatric Diabetes Program, Joslin Diabetes Center, and associate professor, medicine, Harvard Medical School, Boston; Journal of the American Medical Association, April 27, 2021
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