The earlier you get diabetes, the higher your risk of dementia later on

By Denise Mann Health Day Reporter

THURSDAY, May 25, 2023 (HealthDay News) — Prediabetes often precedes type 2 diabetes, the form of the disease most closely linked to obesity.

A new study suggests that the timing of this transition could pave the way for dementia in years to come.

Prediabetes refers to blood sugar or glucose levels that are higher than normal but not high enough to be defined as diabetes.

Researchers found that people who were diagnosed with type 2 diabetes before their 60th birthday were three times more likely to develop dementia than people without diabetes. This increased risk of dementia decreased in people who developed diabetes at a later age. At age 80, for example, the development of diabetes was not associated with a higher risk of dementia.

“Slowing or preventing the progression of prediabetes to diabetes may be an important way to prevent dementia,” said study co-author Michael Fang. He is an assistant professor of epidemiology at the Johns Hopkins University Bloomberg School of Public Health in Baltimore.

It’s not fully understood how, or even if, progression from prediabetes to type 2 diabetes affects dementia risk, but researchers have a theory.

Insulin resistance and hyperglycemia are associated with diabetes and contribute to the buildup of beta-amyloid and tau in the brain. These are hallmarks of Alzheimer’s disease, the most common form of dementia.

“Buildup of beta-amyloid and tau can lead to loss of brain cells, which in turn can lead to dementia,” Fang said.

“It is unclear whether prediabetes is an independent risk factor or whether people with prediabetes are simply at higher risk for diabetes,” he explained. “Our results support the theory that prediabetes is important for dementia, primarily because these patients are at increased risk for diabetes.”

For the study, the researchers analyzed data from around 11,660 people who did not have diabetes at the start of the research. Among them, 20% suffered from prediabetes. People underwent tests measuring cognitive or mental function throughout the study, which lasted nearly three decades.

The earlier people transitioned from prediabetes to diabetes, the more likely they were to develop dementia, the study found. Progression to type 2 diabetes before age 60 was associated with a three times higher risk of developing dementia. This figure dropped to 73% increased risk for those who developed diabetes at age 60 to 69, and dropped further to 23% increased risk for those who developed diabetes at age 70. at 79 years old.

So will preventing the progression of prediabetes to type 2 diabetes reduce the risk of dementia?

That’s hope, Fang said. “Policies that effectively slow the progression of prediabetes can have a big impact on the overall burden of dementia,” he said.

Modest weight loss and participation in programs that encourage healthier lifestyles, such as the National Diabetes Prevention Program, could dent those statistics, he said.

Type 2 diabetes is a well-established risk for dementia, Yuko Hara said. She is director of prevention and aging at the Alzheimer’s Drug Discovery Foundation in New York.

Preventing or managing diabetes is one of the most important things you can do to lower your risk of dementia and protect your brain from cognitive decline, said Hara, who reviewed the new study.

“A healthy diet, exercise and weight control are the first steps in preventing and managing diabetes,” she said. Medicines are also available to keep blood sugar at optimal levels, she said.

SOURCES: Michael Fang, PhD, assistant professor, epidemiology, Johns Hopkins University Bloomberg School of Public Health, Baltimore; Yuko Hara, PhD, director, prevention and aging, Alzheimer’s Drug Discovery Foundation, New York; DiabetesMay 24, 2023

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