Dementia in diabetes is usually a progressive decline in intellectual functioning. In addition, memory loss is a frequent symptom of dementia in diabetics.
What Causes Dementia in Diabetes
Narrowing of the brain vessels is the underlying cause for dementia in a majority of diabetic patients. This is what usually happens. A diabetic person suffers a stroke usually Mini Stroke, due to the narrowed blood vessels. During a mini-stroke, there is a transient cessation of blood circulation to the brain. In this way, multiple mini-strokes lead to the death of brain cells. Consequently, a person starts to lose their intellectual function. Additionally, he may also lose memory, especially memory of recent events. This we call as multi-infarct dementia or vascular dementia.
What Causes Narrowing Of The Blood Vessels
The underlying cause for narrowing of the blood vessels is Insulin Resistance. It is important to remember that diabetes, high blood pressure, cholesterol disorder, and abdominal obesity are the main components of Insulin Resistance Syndrome.
Proper Evaluation Of Dementia
Anyone who has memory loss, a stroke (even a minor stroke), a heart attack, coronary angioplasty, or heart bypass surgery should be evaluated for narrowing of the blood vessels. In simple terms, their health care providers should evaluate them for hypertension, cholesterol disorder, and diabetes or pre-diabetes.
Clinical Evidence that Diabetes Causes Dementia
In a large clinical study (1), of 10,963 people, researchers assessed changes in cognitive function over a six-year interval. They found Diabetes and hypertension to be the strongest predictors of decline in intellectual functioning. Even more shocking, dementia developed as early as the age of forty-seven.
In another study (2), researchers gave 50 grams of rapidly absorbing carbohydrates (one half of a bagel and grape juice) to their diabetic patients. They found that carbohydrate intake was associated with poor memory in these patients.
Other Causes Of Dementia in Diabetes
Besides vascular dementia, some of the other causes for dementia in diabetics include:
- Underactive thyroid
- Vitamin B12 deficiency
- Subdural hematoma
Out of these causes, an underactive thyroid, depression and vitamin B12 deficiency are the most common disorders. Fortunately, these can be easily diagnosed and treated. A low level of vitamin B12 is common in elderly diabetic individuals who are on metformin. Treatment of vitamin B12 deficiency is easy. For example, you can take vitamin B12 sublingual lozenges.
What is Alzheimer’s Dementia
Alzheimer’s dementia is a diagnosis of exclusion. That is, once all the treatable causes of dementia as mentioned above have been excluded, only then should a physician should make the diagnosis of Alzheimer’s dementia.
Diagnostic Testing For Dementia in Diabetes
- Two-hour oral glucose tolerance test to diagnose pre-diabetes or diabetes
- Cholesterol panel, which should include HDL, LDL, and triglycerides
- Ultrasound of carotid arteries to rule out narrowing of the neck arteries
- MRI of the brain to rule out any evidence of a recent or an old stroke
- A thyroid blood panel to diagnose an underactive thyroid
- A blood test for vitamin B12, syphilis, and AIDS
Unfortunately, many physicians do not properly evaluate for the treatable causes of dementia in diabetes. They are in a hurry to label them as Alzheimer’s dementia. Nevertheless, you can prevent as well as treat dementia by proper evaluation of the treatable causes of dementia.
- Knopman D, et al. Atherosclerosis Risk in Communities (ARIC) cohort. Neurology 2001; 56:42–28.
- Greenwood CE, Kaplan RJ, et al. Carbohydrate induced memory impairment in adults with type 2 diabetes. Diabetes Care 2003; 26:1961–1966.