The younger the age at diagnosis for Type 2 diabetes, the higher the risk for Alzheimer's disease and other forms of dementia years later.
Type 2 diabetes is a chronic, progressive illness that can have devastating complications, including hearing loss, blindness, heart disease, stroke, kidney failure and vascular damage so severe as to require limb amputation. Now a new study underscores the toll that diabetes may take on the brain. It found that Type 2 diabetes is linked to an increased risk for 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.
The findings are especially concerning given the prevalence of diabetes among American adults and rising rates of diabetes in younger people. Once referred to as "adult-onset diabetes" to distinguish it from the immune-related "juvenile-onset" Type 1 disease that begins in childhood, Type 2 diabetes is seen in younger and younger people, largely tied to rising rates of obesity. The Centers for Disease Control and Prevention estimates that more than 34 million American adults have Type 2 diabetes, including more than one-quarter of those 65 and over. About 17.5 per cent of those ages 45 to 64 have Type 2 disease, as do 4 per cent of 18- to 44-year-olds.
"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 numerous, but the brain effects are not well studied. Type 2 diabetes is now being diagnosed in children, and at the same time there's an aging population."
For the new study, published in JAMA, British researchers tracked diabetes diagnoses among 10,095 men and women who were ages 35-55 at the start of the project, in 1985 to 1988, and free of the disease at the time.