Back to diabetes. The problem we will discuss is when the pancreas no longer produces insulin or is resistant to it resulting in elevated blood sugar levels called diabetes mellitus but again to simplify, I will refer to as diabetes. Insulin is also important in controlling our metabolism but more on that later.
First, as I wrote above there are many types of diabetes. One form of diabetes occurs from either very little or no insulin secretion, called type I. Another form is where the cells become resistant to insulin, called type 2. There is also what some call type III diabetes.
Type II is where the neurons in the brain that are involved in the body’s metabolism and for example help control appetite are resistant to insulin. However, many scientists consider it part of type II diabetes. For that reason and simplicity of this article I will consider it part of type II diabetes.
So, in diabetes there is either no or very little insulin or the cells are not sensitive to it. Insulin is the bodies main way to prevent blood sugar levels from becoming excessive. Thus, problems occur when insulin is absent, significantly reduced or the tissues are resistant.
As, then there is limited ability for the body to lower blood sugar levels. So, especially with meals containing lots of single sugars (candy bar) or complex sugars like carbohydrates (think breads for one), blood sugar levels can and do rise above normal levels.
In the short term elevated blood sugar levels increases the concentration of the blood resulting in loss of water through urination. It also shifts metabolism to that of fats. This fat metabolism can lead to what is called ketoacidosis. These short term effects if severe can lead to coma and death.
Long term elevated blood sugar levels cause gradual damage to the body. By first effecting the arteries suppling blood and oxygen to the organs in the body. This damage to the arteries, atherosclerosis reduces blood flow and oxygen to our organs. Gradually causing more and more damage to our organ.
The organs effected first are the typically the most sensitive ones; the kidneys, heart and brain. Increased blood sugar levels also hinder the immune system. They also increased infection rate as bacteria for one have more “food” in the form of sugar to feed on. Insulin, other hormones and metabolism.
As I explained in the last blog series proopiomelanocortin (POMC) is a neuropeptide that is broken down into multiple other neuropeptides. Some of these neuropeptides influence appetite. Well in the area of the brain dealing with body energy balance (metabolism) are the POMC neurons.
But also, the cocaine- and amphetamine-regulated transcript (CART) neurons that help control feeding and weight. 1 These neurons are acted on by insulin secreted by the pancreas but also a substance called Leptin which is secreted by white adipose tissue. 2 They both act in a way that prevents obesity.
However, in type II diabetes these brain cells become resistant to insulins and leptin effects. 3,4,5 Thus, promoting obesity as these cells can’t sense insulin or leptin despite elevated levels. Thus, preventing the signaling to reduce food intake. More in next post.
- Sapru HN. (2013). Role of the hypothalamic arcuate nucleus in cardiovascular regulation. Aut neuroscience. 175 (1-2):38-50.
- Belgardt BF, Bruning JC. (2010). CNS leptin and insulin action in the control of energy homeostasis. Ann NY Acad Sci 1212:97-113.
- Considine RV, Considine EL, Williams CJ, et al. (1995). Evidence against either premature stop codon or the absence of obese gene mRNA in human obesity. J Clin Invest 95:2968-2988.
- Maffei M, Haalas J, Ravussin E, et al. (1995). Leptin levels in human and rodent: measurement of plasma leptin and ob RNA in obese and weight-reduced subjects. Nat Med 1: 1155-1161.
- Banks WA, Owen JB, Erikson MA. (2012). Insulin in the brain: There and back again. Pharmacol Ther. 136(1): 82-93.
*The information posted above is for educational purposes only. Always check with your doctor before initiating any changes in your medical treatment. If you do not, then The Two-Minute Health Fact, Dr. Judson Somerville, nor The Optimal Dose is responsible!
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