Is Dementia a Possibility When You Have Diabetes?

High blood glucose levels damage blood vessels throughout the body. There really isn’t any reason to believe that the brain is magically spared. Epidemiological studies evaluating the rates of dementia in people with diabetes confirm this. People with diabetes are at higher risk both for Alzheimer’s disease and another brain disorder called vascular dementia.

Vascular dementia occurs when the blood supply to the brain, which carries life-supporting oxygen and nutrients, is interrupted. Often the symptoms of vascular dementia appear suddenly, although damage may have been building for years. Symptoms may be triggered by a sudden vascular event such as a stroke. Vascular dementia usually proceeds in a step-wise fashion with a long period of consistent mental function and then deterioration to a plateau at the new level. Although memory problems can be part of the syndrome, people often suffer from an inability to complete complex or multi-step tasks. This is especially problematic for people with diabetes who may have to follow intricate insulin dosing regimens. People may also experience episodes of depression, changes in behavior and mood or periods of severe confusion. There may also be deterioration in physical abilities such as balance problems and loss of bowel and/or bladder control.

Alzheimer’s disease is the most common form of dementia, accounting for more than 50 percent of cases. It usually strikes those older than 65, but it can occur in a person’s 40s or 50s. People who have Alzheimer’s have a buildup of distinctive protein molecules in the brain. One of these is plaques made of the protein called beta amyloid that appears between nerve cells. The other is tangles of a protein called tau. Although Alzheimer’s disease shares many of the same traits as vascular dementia, it usually affects memory more severely and generally progresses at a more consistent pace. Alzheimer’s disease is eventually fatal, with people completely losing their ability to interact with others. People with Alzheimer’s disease may also have some aspects of vascular dementia.

How can diabetes contribute to dementia?

Scientists haven’t figured out the precise mechanisms of how diabetes or poor glucose control contributes to dementia—but they have a number of theories. The brain requires high levels of glucose to run efficiently. When it isn’t able to process glucose because of insulin resistance, the brain may not receive the nutrition it requires, causing damage to some of the brain’s blood vessels. In addition, the brain is sensitive to fluctuating insulin levels: either inadequate amounts of insulin or, in some cases of type 2 diabetes, hyperinsulinemia (abnormally high insulin levels) may occur. Inadequate insulin levels prevent the brain’s absorption of glucose. Some researchers believe that high glucose levels make it difficult for the brain to keep the buildup of beta amyloid in check.

There is also a theory that excess insulin levels can disturb the delicate balance of neurotransmitters in the brain, leading to cell damage. Finally, high glucose levels cause inflammation. Although inflammation following an acute injury or illness is the body’s way of fighting disease, a prolonged inflammatory response causes oxidative stress, which stimulates alternations to cell epithelium and contributes to vascular destruction and may also contribute to the development of Alzheimer’s.

At present there isn’t a cure for Alzheimer’s disease or vascular dementia, but a number of treatments are available. Keeping blood glucose as well as blood pressure in control can go a long way in preventing vascular damage throughout the body.

Deterioration in blood glucose control, increasing episodes of low blood glucose events, or the inability to follow through on diabetes personal care in a person who previously was in good control, may mean that a visit to a health professional for cognitive testing is in order.

Live well and enjoy!

Nora