Type 2 diabetes is a chronic, progressive disease that can lead to devastating complications, including hearing loss, blindness, heart disease, stroke, kidney failure, and vascular damage so severe that it requires treatment. amputation of a limb. Now, a new study highlights the consequences diabetes can have on the brain. He found that type 2 diabetes is linked to an increased risk of Alzheimer’s disease and other forms of dementia later in life, and the younger the age at which diabetes is diagnosed, the greater the risk. Student.
The results are of particular concern given the prevalence of diabetes among American adults and the increasing rates of diabetes among young people. Formerly called “adult diabetes” to distinguish it from the type 1 “juvenile onset” disease of immune origin that begins in childhood, type 2 diabetes is observed in younger and younger people. largely linked to rising obesity rates. The Centers for Disease Control and Prevention estimates that more than 34 million American adults have type 2 diabetes, including more than a quarter of those 65 and older. About 17.5% of people aged 45 to 64 have type 2 disease, as do 4% of people aged 18 to 44.
“This is an important study from a public health perspective,” said Yale Diabetes Center director Dr. Silvio Inzucchi, who was not involved in the research. “The complications of diabetes are many, but the effects on the brain are not well studied. Type 2 diabetes is now being diagnosed in children, and at the same time, the population is aging. “
For the new study, published in JAMA, British researchers followed diagnoses of diabetes in 10,095 men and women aged 35 to 55 at the start of the project, from 1985 to 1988, and free from the disease at the time.
They followed them up with clinical exams every four or five years until 2019. With each exam, researchers took blood samples to assess fasting blood sugar, a measure used to detect diabetes, and recorded cases. of type 2 disease self-reported and diagnosed by the doctor. .
Researchers also determined cases of dementia using UK government databases. Over a mean follow-up of 32 years, they recorded 1,710 cases of type 2 diabetes and 639 cases of dementia.
The researchers calculated that each onset of diabetes five years earlier was associated with a 24% increased risk of dementia. Compared to a person without diabetes, a 70-year-old diagnosed with type 2 diabetes less than five years earlier had an 11% increased risk of dementia. But a diagnosis at age 65 was associated with a 53 percent increased risk of subsequent dementia, and a diagnosis at age 60 with a 77 percent increased risk. A person diagnosed with type 2 between 55 and 59 years old had more than twice the risk of dementia in the elderly compared to a person of the same age group without diabetes.
The study was observational and therefore could not prove that diabetes causes dementia. But that was a long time ago, with a large study population. Researchers have controlled many factors that affect dementia risk, including race, education, heart disease, stroke, smoking and physical activity, and the diabetes-dementia link has persisted.
“These are exceptional data,” said Daniel Belsky, assistant professor of epidemiology at the Columbia Mailman School of Public Health who was not involved in the research. “These associations between the time of diabetes onset and the development of dementia show the importance of a lifelong approach to preventing degenerative diseases.
“We are an aging population, and the things we fear most are degenerative diseases like dementia, for which we have no cure, no therapy and very few modifiable pathways to target for prevention,” said the Dr Belsky. “We can’t wait until people are 70 years old.”
It is not known why diabetes is linked to dementia. “We can speculate on the mechanisms,” said the study’s lead author, Archana Singh-Manoux, professor-researcher at INSERM, the French national health institute. “Living with diabetes for a long time and having episodes of hypoglycemia is harmful, and diabetes also has neurotoxic effects. The brain uses huge amounts of glucose, so with insulin resistance the way the brain uses glucose could be changed ”in people with type 2 diabetes.
Type 2 can be managed and its complications reduced by monitoring blood sugar levels and conscientiously following a well-designed and personalized program of medication, exercise and diet. Is it possible that such a routine could minimize the risk of dementia later in life?
“With better control, there was less cognitive decline than in those with poor control,” said Dr. Singh-Manoux. “So stick to your meds. Take care of your blood sugar markers. This is the message for people with diabetes. “