The Disease
Diabetes is a disease involving the failed production or the failed use of insulin in the body. Insulin is a hormone produced by the islet cells of the pancreas, essential for the metabolism of carbohydrates (sugars), the basic fuel for cells throughout the body.
• In Type 1 diabetes, the body fails to produce insulin as a result of an autoimmune response in which the immune system does not recognize its own islet cells and destroys them. This type of diabetes generally occurs in people under the age of 40 and is most commonly acquired during childhood. Type 1 diabetes is treated by insulin injections and diet.
Fig. 1 Type 1 Diabetes
• “Type 2” diabetes is the most common form of diabetes (90-95% of diabetes patients). It is also referred to as non-insulin dependent diabetes and presents as high blood glucose levels despite an initial abundance of the hormone insulin. The cells of the body ignore the insulin and do not allow glucose to enter the body's cells. This insulin resistance leads to high levels of glucose in the bloodstream, and eventually to beta-cell failure, where the beta-cells of the pancreas are no longer able to release insulin in response to high blood glucose levels. Type 2 diabetes usually appears in those over 40, and is treated by diet alone, or by diet and oral medications.
Fig. 2 Type 2 Diabetes
The following are common complications associated with diabetes:
• Hypoglycemia (low blood sugar)
• Hyperglycemia (high blood sugar)
• Ketoacidosis -- A serious condition due to the buildup of ketones in the body; it can lead to diabetic coma or death
• Heart disease and stroke – Two out of three diabetes patients die from heart disease or stroke.
• Kidney disease – High levels of blood sugar cause the kidneys to filter larger amounts of blood, and over time, the kidneys can become damaged from this rigorous usage. As a result, useful proteins that the kidney's filtering system usually retains in the blood are lost in urine, resulting in microalbuminuria or macroalbuminuria just before end-stage renal disease.
• Eye complications (diabetic retinopathy) – Those with diabetes are 40% more likely to develop glaucoma (pressure buildup in the eye, which pinches the blood vessels that carry blood to the retina and optic nerve, leading to vision impairment). Those with diabetes are 60% more likely to develop cataracts (a condition where a film clouds over the eye's clear lens, blocking light).
Islet Cells
Islet cells, or Islets of Langerhans are vascularized clusters of cells within the pancreas which contain the insulin-producing beta cells. There are three types of islet cells: beta cells, which produce insulin; alpha cells, which produce glucagon, a homrone that raises the level of blood glucose; delta cells, which produce somatostatin, an enzyme believed to regulate insulin and glucagon production.
Fig. 3 Islet Cells in the pancreatic glands
Fig. 4 Location of human beta cells in the Islets of Langerhans
Traditional Therapies
• Testing blood sugar levels: Monitoring glucose levels is an important part of managing diabetes.
• A1C test: The A1C test is performed in a lab using the blood of a diabetes patient. A1C test results show your average blood glucose control level over the past 3 months.
• Blood glucose meter: Glucose meters are small, battery-operated devices that read the glucose level when a test strip with the person's blood is placed inside the meter.
• Exercise and diet: Because those with diabetes must manage their blood glucose levels more cautiously, a healthy diet and exercise are recommended as lifestyle therapies. Amongst other precautions, people with diabetes should watch the number of grams of carbohydrate in their meals, because carbohydrates have the most effect on blood sugar levels. Diabetics should work with a dietician to manage their daily intake of foods. Also, regular exercise helps to improve the body's use of insulin. Exercise also lowers body fat and LDL cholesterol, helping to control body weight and risk of heart disease.
• Oral pill therapies: Sulfonylureas, which lower blood glucose by stimulating the pancreas to release more insulin; biguanides, which improve the insulin's ability to move glucose into cells; thiazolidinediones, which improve insulin's effectiveness in tissue. Often these drugs are prescribed in combination to achieve maximal effectiveness of blood glucose control.
• Insulin: As of now, insulin can only be administered by injection or by insulin pump. Scientists hope to develop alternative delivery methods such as a nasal spray or pill. People with diabetes need to measure and observe their blood glucose levels to effectively control their diabetes. When blood sugar levels are high, insulin needs to be administered externally as a means to compensate and bring glucose levels back to normal. People with diabetes may have to take insulin treatments up to four or five times a day.
Fig. 5 Administration of an insulin shot
Qualitative & Quantitative Effects
Diabetes Mellitus, commonly known as diabetes, comes in different forms and affects all age groups. In the United States , 18.2 million people, or 6.3% of the population, have been diagnosed with diabetes. Diabetes is the 7th leading cause of death in the United States and is the number one cause of blindness, chronic renal failure, and non-traumatic lower extremity amputations. In 2002, approximately $132 billion was spent on direct and indirect costs of diabetes in the United States. These figures illustrate the need for better solutions in diabetes treatment and prevention. Currently, a large sector of the medical and research community is devoted to finding those solutions.
References:
1. http://my.webmd.com/medical_information/condition_centers/diabetes_1_2/default.htm
2. http://www.diabetes.org/about-diabetes.jsp
3. http://www.diabetes.org.uk/home.htm
4. http://diabetes.niddk.nih.gov/
5. http://classes.kumc.edu/som/diabetes/background.htm
Image References:
Fig. 1: http://www.umm.edu/future/diabetes.html
Fig. 2: http://my.webmd.com/content/article/59/66844
Fig. 3: http://www.mhhe.com/biosci/ap/histology_mh/glands.html
Fig. 4: http://www.insulinfree.org/islets/gray_fig1.htm
Fig. 5: http://www.dagbladet.no/dinside/2003/10/08/380487.html
