In class this week, we talked about the connection between Insulin, Diabetes, and Alzheimer’s Disease. In type 1 diabetes, the cells of the pancreas that create insulin stop producing it. One of the most common ways of combating this disease is to give regular insulin shots. Type 2 diabetes is characterized by insulin resistance: although the body may have regular levels of insulin, the effect of insulin is decreased, usually from fewer receptors. Alzheimer’s disease is characterized by dementia: as state where the patient suffers impairments to cognition, reasoning and communication skills as well as confusion about the time and place and delirium for a prolonged period of time. Connections seen between Alzheimer’s disease and diabetes or insulin resistance has caused some to call it type 3 diabetes.
Insulin controls the uptake of glucose into cells so that they can be active and use energy. In the case of insulin resistance, insulin is unable to fully perform its job of having cells take in glucose. This has been theorized to be part of why Alzheimer’s patients have cognitive defects: in the dearth of glucose, they are less responsive which leads to mental impairment. To deal with low levels of energy, sometimes the cell will also consume important molecules for the cell’s integrity or be unable to produce important molecules leading to cell death; which, in the case of the brain leads to even more irreversible mental impairment.
Another key function of insulin is the role that it plays in aging. In all animals, insulin controls the expression of age related characteristics (think about things like grey hair, facial hair, and so on); insulin levels are responsible in part for the age of our bodies. One of the defining characteristics of the aging brain is that it develops insulin resistance and consequently becomes mentally impaired. This supports the belief that all brains will eventually develop dementia like symptoms and that Alzheimer’s disease only brings it about sooner. One implication of that is that this will lead to sooner onset of dementia in people who have diabetes. This could prove to be a problem for our nation as generations with higher levels of diabetes get older.
Aging, Diabetes, Alzheimer's and Insulin
