Glucose Facts

Glucose is a type of sugar used as an energy source by the body. The liver produces a small amount of glucose, but most comes from food. Rice, pasta, bread and other carbohydrate-rich foods increase glucose levels in the body more than other foods. The body absorbs glucose into the bloodstream after meals and distributes it to the cells. The hormone insulin, produced in the pancreas, helps the cells turn glucose into energy. Excess levels of glucose are stored in the liver, muscles and fat cells for later use. The body performs an intricate balancing act to keep glucose at optimal levels throughout the day.

Normal Levels

• The American Diabetes Association states normal fasting blood glucose levels are between 70 and 100 and after-meal levels should be lower than 140. The association recommends anyone with diabetes have an A1C test, which gives an average of the last three months blood glucose levels, every three months.

Lab Tests

• Lab Tests Online shows the following guidelines for above normal blood glucose levels: levels between 100 and 125 indicate pre-diabetes or impaired fasting glucose and a reading over 126 indicates diabetes. It should be noted the ADA requires a reading of over 126 on more than one occasion to diagnose diabetes.

Oral Glucose Tolerance Test

• The OGTT or oral glucose tolerance test is also used to determine diabetes. A 75 g glucose drink is ingested and two hours later, blood is drawn. A reading of less than 140 mg/dl is considered normal, a reading between 140 and 200 shows pre-diabetes, and more than one reading over 200 indicates diabetes.

Type 1 Diabetes

• The National Institutes of Health reports of a study showing that intensive blood glucose control in Type 1 diabetics reduces the chance of complications for those with the disease. Strict glucose control should be implemented as soon as possible after a diagnosis of Type 1 diabetes for optimal results.

Conditions Associated with High Glucose Levels

• Along with diabetes, other conditions that can raise glucose levels include acute stress, pancreatic cancer, Cushing syndrome, hyperthyroidism, pancreatitis, chronic renal failure and acromegaly, which is a condition caused by excess growth hormones. Excessive food intake and certain drugs such as corticosteroids, antidepressants and diuretics among others can also increase glucose levels.

Conditions Associated with Low Glucose Levels

• Adrenal insufficiency, liver disease, hypothyroidism, hypopituitarism, insulin overdose, starvation and insulinomas, which are tumors of the islet cells in the pancreas, are all conditions that cause low blood glucose levels. Alcohol abuse and drugs like acetaminophen and anabolic steroids can also lower glucose levels.