Many people have the perception that type 2 diabetes is a health risk only for overweight individuals. It is true that those who are obese account for approximately 60% of the 17 million adults with diabetes in the United States. However, aging also plays a significant role in increasing the odds of developing type 2 (adult onset) diabetes. As we age, our cells become more resistant to insulin. The onset of type 2 diabetes occurs more than 50% of the time in adults over 55 years of age, according to the American Diabetes Association (ADA).
The hormone insulin is essential for enabling our bodies to use glucose (blood sugar) for energy. In type 2 diabetes, the body does not produce enough insulin or the cells ignore the insulin. Glucose is the basic fuel for our body’s cells and is created when our body breaks down the sugars and starches in the foods we eat. Insulin carries this blood sugar into our cells for energy. When glucose builds up in the blood instead, it can lead to diabetes complications.
Certain factors besides obesity and age put patients at greater risk for developing type 2 diabetes. These include excessive fatty tissue around the abdomen, high cholesterol and glucose intolerance. Importantly, people with high blood pressure are more than twice as likely to develop type 2 diabetes than those with normal blood pressure.
Today, doctors are utilizing a blood test called the hemoglobin A1C to help identify those individuals at risk for developing diabetes. This A1C test has been used for years to monitor blood sugar levels of patients who have already been diagnosed with diabetes. The general goal recommended by the ADA is below 7%, but higher or lower goals may be appropriate for a given individual.
In January 2010, the ADA began recommending that physicians utilize the hemoglobin A1C to identify patients at increased risk of developing type 2 diabetes. The traditional normal range in non-diabetics for an A1C test is 4-6%. To use the A1C test to screen for increased risk of diabetes, the ADA splits the A1C results into three categories: normal (5.6% or less), prediabetes (5.7% to 6.4%) and diabetes (6.5% or more). The higher the A1C, the greater the risk of developing diabetes. Pre-diabetes in this context implies that the patient is at an increased risk of diabetes. However, this simplification does not take into account ethnic or genetic variability of A1C results. For example, A1C averages 0.3% higher in African-Americans and averages 0.3% lower in Asians. The A1C test can also be misleading in patients who have other medical conditions that make the result falsely low, such as bleeding or hereditary spherocytosis (a condition affecting the red blood cells that causes anemia, among other symptoms). So, sometimes the A1C result is only part of the story, and the fasting glucose or post-meal glucose has to be considered as well.
The value of the new category of pre-diabetes (increased risk of diabetes) is that we have proof that diet and exercise can help reduce the risk of progressing to overt diabetes. The Diabetes Prevention Trial has shown that patients “at risk” for type 2 diabetes reduced their risk of progressing to overt diabetes by 60% through a program of diet and exercise; the benefit was primarily related to weight loss.
If you have had an A1C test for screening for diabetes, your doctor will help evaluate the number for you and make recommendations. Whether your test results are normal, pre-diabetic or diagnostic for diabetes, you can do your part to optimize your health by eating a low carbohydrate diet and by getting regular exercise.
By David S. Oyer, MD, FACE