Diabetes 101 - By Naomi Cook

Naomi Cook earned her bachelors in Animal Science from Cornell University and received her masters from NYU in Science Education. Currently Naomi teaches AP Biology in Wetchester, NY. She includes concepts from both Type 1 + 2 Diabetes in her core curriculum.

Diabetes is literally a disorder that results in increased urination. This can be directly caused by a higher than normal blood glucose (sugar) level, as the kidneys work harder to rid the body of the excess glucose. The hormone insulin is produced by the pancreas and acts like a chemical messenger that instructs cells to allow glucose in. Once in the cell, glucose can be oxidized to release energy for life functions or it can be stored in the cells of the liver as a molecule called glycogen. When insulin is produced and cells are responding to it properly, blood glucose levels are stable. When a person’s cells become either unable to respond to insulin or unable to produce insulin, blood glucose levels increase and Diabetes results. There are two types of Diabetes, Type I and Type II.

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Type I Diabetes occurs when the body stops producing insulin, usually during childhood. The Type I Diabetic injects insulin in order to regulate his or her own blood glucose level. There is currently no cure for Type I Diabetes. Type II Diabetes occurs when the body continues to produce insulin, but cells become unresponsive to the insulin. Therefore, Type II Diabetics do not take insulin. Instead, they regulate their blood glucose levels through diet and exercise. Unlike Type I, Type II Diabetes usually develops in adulthood.

In Type I Diabetes, the insulin producing cells of the pancreas called the Islets of Langerhans, are attacked by the person’s own immune system. We do not know why this happens yet, but it usually occurs in childhood and scientists think that it may be linked to genetics or viral infections. As a result, that person stops producing insulin, and blood glucose levels increase. This is called hyperglycemia and occurs when a Type I Diabetic eats a large meal. The person will experience increased urination, thirst, fatigue, blurry vision and nausea. In order to prevent this, he or she injects insulin, which will lower blood glucose.

If too much insulin is taken, hypoglycemia (low blood sugar) can occur. This is process is exaggerated with either not enough food intake or when the person engages in physical activity. The symptoms of hypoglycemia are sweating, shakiness, hunger and dizziness. If not treated, hypoglycemia can result in slurred speech, drowsiness, confusion and in its worst case, diabetic coma as the organs of the body shut down because they are starved for glucose. The most effective treatment is ingesting anything with high levels of sugar such as juice or candy.

A condition called ketoacidosis may also result because cells are not getting the glucose they need. This can happen if the Diabetic is not taking his or her insulin and glucose is not able to enter into the cell. Cells will begin to excessively utilize fats and proteins for energy. Unfortunately, the byproducts of this reaction are ketones, which are toxic to the body.

The Type I Diabetic is responsible for lowering blood glucose after a meal by injecting insulin, but not letting it get so low that hypoglycemia begins to happen. It’s a difficult task. Because insulin is a peptide (a small protein) it can not be taken as a pill. Proteins are digested into their amino acid building blocks in the stomach, before the Diabetic can absorb the insulin into the blood stream. Therefore, it must be injected, making treatment even more complicated, but extremely important.

If not controlled, the short term effects of hypoglycemia can be dramatic and dangerous. The long term effects of hyperglycemia can seriously affect quality of life. Damage to the tissue of the heart can lead to heart attack, stroke and high blood pressure. Damage to blood vessels serving the retina can lead to blindness. Nerve damage in the leg may lead to tingling, numbness and an inability for wounds to heal. Nerve damage to the kidneys can result in kidney failure.

In Type II Diabetes, the person’s cells become unresponsive to insulin, even though the pancreas continues to produce it. Similar to Type I Diabetes, blood glucose levels will increase. Because cells are unresponsive to insulin, Type II Diabetics do not control their sugar by taking insulin. They must do so through diet and exercise. As Type II Diabetes progress, the pancreas continues producing insulin even though cells remain unresponsive, and can eventually become overwhelmed. At this point, the Islets of Langerhans stop producing insulin and the Diabetic may need to start insulin treatment. Type II Diabetics can suffer from hyperglycemia and will also suffer from hypoglycemia if they are on glucose lowering medications. If blood glucose is not regulated, the long term effects of hyperglycemia will damage tissue just as it does with the Type I Diabetic.

Although the exact mechanism for developing Type II Diabetes is unknown, certain factors seem to increase the likelihood that a person’s cells will become unresponsive to insulin. Excess fatty tissue and inactivity is linked to Type II Diabetes. Unlike Type I Diabetes, a person’s risk increases with age. There also appears to be a genetic link to Type II Diabetes. A person’s risk increases if a sibling or parent has the disease, and certain races such as Asians Americans, Native Americans, Hispanics and Blacks have higher incidences of Type II Diabetes.

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