What Is Diabetes?

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By Debra A. Sokol-McKay,
MS, CVRT, CDE, CLVT, OTR/L, SCLV

Definitions of Diabetes
A Metabolic Disorder
A Chronic, Progressive Disease
A Growing Public Health Concern

Definitions of Diabetes

Diabetes Mellitus has several definitions:

  1. A metabolic disorder
  2. A chronic, progressive disease
  3. A growing public health concern.

Diabetes is characterized by a high level of glucose in the bloodstream, also known as hyperglycemia. Glucose is the principal circulating sugar in the blood and provides energy to all cells in the body.

These cells cannot use glucose, however, without the help of insulin. Insulin is a hormone produced by the pancreas that converts sugar and starch from food into the energy needed to fuel everyday activities.

Diabetes occurs when

  • the pancreas does not make or release enough insulin,
  • the body's cells are resistant to insulin, or
  • both conditions are present.

A Metabolic Disorder

Metabolism is a term that describes the processes through which food is converted into energy for your body to use immediately or store for later use.

In normal food metabolism:

  • The food you eat is broken down into glucose and other simple sugars and enters your bloodstream;
  • Your body senses the rise in blood glucose and signals your pancreas to release insulin into your bloodstream;
  • The released insulin acts as a "key" that unlocks your cells and allows glucose to enter;
  • Your cells absorb glucose to provide energy for physical activity.

The foods you eat that break down into glucose are called carbohydrates, which:

  • Are one of the three main nutrients in food, in addition to proteins and fats;
  • Include sugars and starches contained in fruit; breads and cereals; milk and dairy; starchy vegetables such as corn, potatoes, and peas; cake and ice cream;
  • Cause blood glucose levels to rise about one to two hours after a meal;
  • Determine how high or low blood your glucose levels will go, according to the type and amount of carbohydrate-containing foods you eat.

When this process occurs as it should, the glucose level in your bloodstream remains within a normal range of 70 to 100 milligrams per deciliter (mg/dL). In type 1 and type 2 diabetes, however, this process does not occur properly, which results in a serious, lifelong metabolic disorder.

Type 1 diabetes (formerly called juvenile-onset, Type I, or insulin dependent) has the following characteristics:

  • It usually occurs before age 30 and affects 5%-10% of individuals with diabetes.
  • It occurs when the body produces little to no insulin (insulin deficiency).
  • Glucose continues to rise in the bloodstream because it cannot enter the body's cells
  • The body's immune system destroys its own insulin-producing cells in the pancreas, for reasons that are not yet clear to researchers. Possible reasons include genetic factors, viruses, or a defect in the body's autoimmune system.
  • Insulin shots are required to sustain life.

Type 2 diabetes (formerly called adult-onset, Type II, or non-insulin dependent) has the following characteristics:

  • It usually occurs after age 30 and affects 90%-95% of individuals with diabetes.
  • It occurs if (1) the pancreas does not produce enough insulin (insulin deficiency), (2) the body's cells are not able to use insulin correctly and efficiently (insulin resistance), or (3) both conditions are present.
  • Glucose continues to rise in the bloodstream because sufficient levels of insulin are not available to open the cells and allow glucose to enter.
  • It can be managed initially with weight loss, physical activity, and effective meal planning and for some individuals this suffices for a period of time; when the disease progresses, however, oral medication or insulin may also be required.
  • Primary risk factors include increasing age (45+); ethnic background (African-American, Latino, Native American, Asian); family history; and obesity.

A Chronic, Progressive Disease

  • Diabetes is a condition that is treatable but not curable.
  • There is no such condition as "having a little bit of sugar" or "a touch of sugar." An individual either has diabetes or does not.
  • There is, however, a condition called pre-diabetes in which blood glucose levels are higher than normal, but are not yet high enough to be diagnosed as diabetes.
  • Individuals with pre-diabetes have a significant risk for progressing to diabetes, and an elevated risk for heart disease and stroke.
  • An individual can be diagnosed with diabetes if he or she has classic symptoms of high blood glucose – excessive thirst, frequent urination, increased appetite and unexplained weight loss, and has a blood glucose level of 200 mg/dL or greater on a Random Plasma Glucose Test (RPG).
  • Several other tests can diagnose both diabetes and pre-diabetes: (a) the Fasting Plasma Glucose Test (FPG), (b) the 2-Hour Oral Glucose Tolerance Test (OGTT), and (c) glycated hemoglobin (A1C).
  • The FPG is used more frequently. When your doctor prescribes blood work and tells you not to eat the night before, he or she is probably checking for diabetes or pre-diabetes by using the FPG test.
  • An FPG test that reports blood glucose levels between 100 mg/dL and 125 mg/dL indicates pre-diabetes or impaired fasting glucose. Diabetes is present when the result is 126 mg/dL or greater. A repeat test will confirm the results.
  • Hemoglobin A1C can be measured without fasting. This test measures your average blood glucose control for the past 2 to 3 months. A level between 5.7 and 6.4 suggests an increased risk of developing diabetes; a level greater than or equal to 6.5 indicates diabetes.

Here is a comparison between A1C and average blood glucose level:

Diagnosis A1c level
Normal below 5.7 percent
Pre-diabetes5.7 to 6.4 percent
Diabetes 6.5 percent or above

A Growing Public Health Concern

  • In 2012 (the most recent data available), the American Diabetes Association reported that 29.1 million children and adults in the United States have diabetes, or about 9.3% of the population.
  • The fastest-growing segment of the population diagnosed with type 2 diabetes is individuals aged 65 and older, or about 25.9% of that population group.
  • Type 2 diabetes is becoming more prevalent in children, due to poor eating habits and lack of exercise.
  • The Centers for Disease Control and Prevention (CDC) estimates that approximately 86 million Americans have pre-diabetes.

Personal Stories

  • Vivian: Living with Diabetes and Visual Impairment
    Vivian was diagnosed with diabetes twenty years ago, at age 58. Ten years later, she was diagnosed with diabetic retinopathy and spinal stenosis. She talks about how she is living and coping with her diabetes and some of the tools and techniques she uses.

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