Last week I went over some of the basic biology of diabetes. This week I would like to explore its diagnosis and treatment.

It's estimated that seven million people the U.S. are going about their daily lives unaware that they are diabetic. Many have no symptoms, and those who do often ignore them or are not aware they should be concerned.

Recall that common symptoms of diabetes include frequent urination, excessive thirst, increased appetite, and blurred or fluctuating vision. Type 1 diabetics may present with more severe symptoms such as lethargy, dehydration or weight loss. People who have a family history of diabetes or who are obese are at higher risk and should be vigilant for diabetic signs and symptoms.

Once a person is suspected of having diabetes, a number of tests can be performed to confirm the diagnosis. The most common is the fasting plasma glucose (FPG). A normal value is 70-100 mg/dL. To be diagnosed as being diabetic, a person has to have a FPG over 126 mg/dL. Patients with FPGs in the 100-125 range are considered pre-diabetic and require close monitoring.

Patients can also be diagnosed using a test called a hemoglobin A1c or "glycated hemoglobin." This test determines how high the patient's blood sugar has been on average over the past four weeks or so. Diabetes is present when the A1c value is over 6.5 percent.

Sometimes the patient is given a glucose tolerance test. This involves drinking a solution containing 75 grams of glucose. Diabetes is diagnosed if the plasma glucose is greater than 200 mg/dL two hours later. A person who has classic signs and symptoms of diabetes and a random plasma glucose value over 200 is also diabetic.

An evidenced-based approach to the management of diabetes is critical. There are five accepted interventions, in order of importance, which can help minimize the damaging effects of diabetes. The first is smoking cessation that has the greatest likelihood of benefit. This is followed by blood pressure control, taking the drug metformin, control of elevated lipids (cholesterol), and finally control of blood sugar.

Treatment of diabetes is very individualized, but there are some basic concepts that apply to all diabetics. Exercise (both aerobic and weight training) and weight loss are key elements diabetes management. Diet is critical but is not as simple as just avoiding sugar. Most diabetics will benefit greatly from attending diabetic education classes and meeting with a dietician to help them plan their meals.

The only treatment option in Type 1 diabetics (who do not make insulin) is to replace the insulin. This can be done via injections taken multiple times a day, or by an insulin pump. The pump is a device about the size of a pager that pumps the insulin through tubing and a disposable needle implanted under the skin. The pump allows much better control of plasma glucose and has revolutionized the treatment of Type 1 patients.

There are numerous medications to treat Type 2 diabetics. They work in different ways and can be used alone or various combinations. Recall that the problem in Type 2 diabetes is insulin resistance - the cells don't respond to insulin. As I mentioned above, the drug metformin is the mainstay of drug therapy in Type 2 diabetes. It increases the ability of the cells to recognize glucose. It also decreases the production of glucose by the liver and its absorption from the intestine.

There are multiple other medications that come in both pill and injectable forms that are used to treat Type 2 diabetics. They all work by different mechanisms to lower blood sugar.

Lastly, insulin is being used more frequently in the treatment of Type 2 diabetics. The available formulations often allow for a single injection daily and the needles have advanced to the point they cause very little discomfort. Many patients feel that insulin is the "end of the line" and are frightened to start therapy. It should, however, just be seen as one more weapon doctors have to treat this potentially devastating disease.

Monitoring treatment of diabetics can be done a number of different ways. Most physicians like to have their patients check their glucose levels at home using a glucose meter. This has the added benefit of allowing the patient to be a more active participant in their diabetes management.

Lab measurements can also be performed that give an idea of long-term control. The most widely used test is the Hemoglobin A1c. You recall it can be used to diagnose diabetes as well. Recall a level of 6.5 percent is the cutoff for diabetes. The American Diabetes Association recommends a goal A1c of less than 8 percent.

Dr. John Roberts is a Crawfordsville physician and one of the owners of The Paper. In addition to his weekly column, he writes a daily health tip that can be found on page A1.