As the daughter of a person with diabetes, Nancy knew she was at higher risk of developing the disease. Last week, she asked to be tested for diabetes. The test involved drinking a special glucose mixture, then having blood taken two hours later. Today, when Nancy returned for her results, her doctor told her she has impaired glucose tolerance.
"Does this mean I am diabetic?" asked Nancy.
"Not quite. Impaired glucose tolerance is a state between normal blood glucose and diabetes," said Dr. Smith. "Your blood test result was 8.2 mmol/L. We say that a person has impaired glucose tolerance if his or her blood glucose is between 7.8 to 11.0 mmol/L two hours after the glucose drink. Your test result is high, but not high enough to be called diabetes."
Impaired glucose tolerance is sometimes inappropriately called borderline diabetes. People with impaired glucose tolerance are more likely to develop Type 2 diabetes within seven or eight years. They are also at risk of developing gestational diabetes (high blood glucose during pregnancy) and cardiovascular diseases such as heart attack or stroke.
"There are no signs of impaired glucose tolerance except that the results of your blood test were high. It was good that we checked you for diabetes. Many people have impaired glucose tolerance and don't know it," Dr. Smith said.
Nancy had been at higher risk of developing impaired glucose tolerance for a few reasons.
Having a relative with diabetes, being over 45 years of age, being overweight, having high cholesterol, having high blood pressure
and being less active are all risk factors.
Dr. Smith explained that Nancy could take steps to safeguard her health. The Finnish Diabetes Prevention Study involved 522 people with impaired glucose tolerance. In the study, the group that made changes to their diet and exercise and lost an average of eight pounds lowered their risk for developing diabetes by 58 per cent.
"That isn't even a lot of weight to lose," said Nancy.
"I know you can do it, Nancy," said Dr. Smith. "Losing weight is an important step towards decreasing your risk. Let's make an appointment for you to see a dietitian so you can get advice on low fat, high fibre foods that will help to lower your cholesterol levels and your weight."
"Until you have your appointment with the dietitian, try to eat balanced meals by following Canada's Food Guide. Choose whole grain breads and cereals, and fruits and vegetables to help you feel full. Eat foods that are lower in fat. Try to eat smaller portions to help you lose weight."
Nancy also needed to include more exercise into her routine. She had already been thinking about starting a walking program. She decided to walk in the morning before her day got too busy, and to take her husband along for moral support.
"We'll need to retest you for diabetes every year and check your cholesterol levels," said Dr. Smith. "Having impaired glucose tolerance is a risk factor for heart disease and it is important that you have a plan to lower that risk. Come back to see me in three months and we will talk about how you are doing with your lifestyle changes."
Nancy's story is not unusual. If you are over 45 years of age, ask your doctor to test you for diabetes every three years. Learn more about the results of your blood tests. If you have impaired glucose tolerance, ask to be referred to a dietitian for tips on healthy eating, and increase your activity. If you have high cholesterol, high blood pressure or high blood glucose levels, learn about what you can do to improve your health. Stay informed and active in your health care!