Insulin: Its Role in the Body and What Goes Wrong During Diabetes
When a patient is diabetic, it can mean three different things. First is what many people commonly think of when they hear the word diabetes: the pancreas is not producing enough insulin and sometimes none at all. The second definition is insulin resistance: when the body does not respond properly to the insulin that is produced. The third definition is a combination of the two.
Insulin is a hormone created and secreted by the pancreas which allows the body's fat and muscle cells to properly use and store glucose. When there isn't enough insulin the insulin doesn't work properly, the glucose remains in the blood stream. The pancreas is the carrot-shaped organ situated just inferior to the liver in the image below. The beta cells in the pancreas produce insulin in a person without diabetes.
Types of Diabetes
Type one diabetes, also called juvenile diabetes or insulin-dependent diabetes is a condition in which the pancreas fails to produce adequate amounts of insulin. DM1 is treated with daily injections of insulin as well as other treatments to facilitate blood glucose control. Causes are unclear, but genetics and autoimmune conditions are suspected.
Type two diabetes is caused by insulin resistance and is often considered a preventable disease caused by unhealthy lifestyle choices. Obesity and poor diet choices are linked to the development of DM2, but they are not the only causative factors. Family history, a history of gestational diabetes and increasing age are also risk factors.
Gestational diabetes is diabetes which develops in a woman at any point during her pregnancy. It is considered a risk factor for developing DM2 later in life.
Symptoms and Diagnosis of Diabetes Mellitus
The symptoms of diabetes are those caused by elevated glucose and include:
- Blurry vision
- Thirst and frequent urination
- Fatigue
- Unintentional weight loss
- Hunger
Urinalysis can indicate a risk of diabetes, but confirmation is needed through blood testing. A fasting blood glucose of 126mg/dL in two separate lab tests is considered standard diagnosis criteria. A hemoglobin A1c (HbA1c) test can be performed. A1c levels below 6% are considered normal and above 6.5% is considered diabetic. A1c testing measures the amount of glucose that is bound to hemoglobin in the blood, and provides an overview for doctors of the overall control of blood glucose over the past 60 to 90 days.
Treatment of Diabetes and Management of Symptoms
- Insulins are used to replace the insulin in the body when the body does not produce it. Therefore, insulin is usually only used to treat type 1 diabetes.
- Type 2 diabetes is usually treated with oral agents such as biguanides, which decrease glucose production in the liver and absorption in the small intestine.
- Enzyme inhibitors disable the breakdown of incretin, a substance which increases insulin production of insulin and decreases the release of glucagon.
- Incretin mimetics are like a synthetic incretin, which yields the same effects as incretin.
- Meglitinides require functional beta cells in the pancreas, but cause an increase in insulin production by forcing potassium channels closed.
- Sulfonylureas stimulate the release of insulin from the pancreas and increase responsiveness to it at receptor sites.
- Thiazolidinediones increase insulin sensitivity in patients with type 2 diabetes.
Until Next Time,
C. Samuels
Resources
"Diabetes." PubMed Health. A.D.A.M., Inc., 10 May 2010. Web. 30 Jun 2011. <http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0002194/>.
Horton, Edward S. "What Is A Hemoglobin A1c Test And When Is It Done?." ABC News. ABC News, 14 Aug 2008. Web. 30 Jun 2011. <http://abcnews.go.com/Health/DiabetesScreening/story?id=3813024>.
"Picture of the Pancreas." WebMD.com. Web. 30 Jun 2011. <http://www.webmd.com/digestive-disorders/picture-of-the-pancreas>.
No comments:
Post a Comment