Diabetes is a chronic metabolic disease in which the pancreas either doesn’t produce insulin (type 1) or the body doesn’t properly use insulin (type 2). Diabetes is extremely common, and its prevalence worldwide is rising. Approximately 422 million people worldwide are living with diabetes.
Although it’s widely known that diabetes increases the risk of many serious health complications, including heart disease, chronic kidney disease, and nerve damage, increasing evidence suggests a relationship between diabetes and cognitive decline. Several researchers have proposed a new clinical entity of a dementia subgroup, referred to as “diabetes-related dementia.”
This article will discuss the following aspects of this relationship:
A growing body of research suggests that diabetes predisposes people to cognitive decline, which may ultimately lead to dementia development. Research indicates that people living with diabetes have higher incidences of all-cause dementia, Alzheimer’s disease, and vascular dementia than individuals with normal glucose tolerance. This relationship is evident in studies of both animals and humans with type 1 and type 2 diabetes. However, current evidence suggests that the association between dementia and type 2 diabetes appears stronger than that of type 1 diabetes.
One study found that type 2 diabetes is associated with a 50% increased risk of developing dementia. Additionally, type 2 diabetes is associated with impaired cognitive functions, including attention, processing speed, executive functioning, motor speed, and verbal memory.
Early research suggests glycemic control may influence the degree of dementia risk. One study found that among older people with type 1 diabetes, those with majority exposure to A1C 8-8.9% and ≥9% had an increased dementia risk, while those with majority exposure to A1C 6-6.9% and 7-7.9% had a reduced dementia risk.
Further research is underway to determine the impact of diabetes severity and duration on dementia risk.
Currently, the exact mechanism(s) linking diabetes and cognitive decline are unclear. However, many believe the connection results from damage due to high blood glucose levels. When people living with diabetes experience high blood glucose levels over long periods (months or years) without treatment, it can cause permanent damage to parts of the body, including the cardiovascular system.
Consequently, people living with diabetes are at an increased risk of heart disease, stroke, hypertension, and atherosclerosis. Because cardiovascular conditions and risk factors are associated with an increased risk of dementia, diabetes may also increase the risk of dementia.
Additionally, conditions that reduce blood flow to the brain, such as chronically damaged or narrowed blood vessels, may cause vascular dementia. Therefore, damaged or narrowed blood vessels in the brain may contribute to cognitive decline and dementia risk.
Finally, high blood glucose levels may increase systemic inflammation, which may damage neurons and contribute to cognitive decline.
The relationship between diabetes and cognitive decline highlights the need for regular cognitive testing. Early and routine cognitive testing is important for everyone throughout the aging process, but for people living with diabetes, impaired cognitive function can negatively impact diabetes treatment adherence, putting them at risk of serious complications and adverse health outcomes. Additionally, many approved and emerging Alzheimer’s disease-modifying therapies may only be effective during the early stages, making early diagnosis even more crucial.
Early detection of cognitive changes makes it possible for individuals and their families to make lifestyle changes for better brain health, gain access to treatment and additional support, and participate in clinical trials, among a host of other medical, social, and emotional benefits.
Altoida’s mission is to accelerate and improve drug development, neurological disease research, and patient care. To learn more about our precision neurology platform and app-based medical device, contact us today.