Living with Diabetes and Cancer
by by Sonali N. Thosani, MD, and Victor R. Lavis, MD
Nearly 26 million people in the United States are living with diabetes. Of those 26 million people, 7 million don’t know they have it. An even greater number, 79 million people have a condition called pre-diabetes, which means they are at a very high risk of developing diabetes.
The Basics of Diabetes
Blood glucose, or blood sugar, is what provides your body with energy. Your body gets glucose from the foods you eat. You need an adequate amount of glucose in your blood to stay healthy, but if too much glucose is present, your body releases insulin, a hormone produced by the pancreas, to regulate glucose levels in the blood. If your blood glucose level stays too high for too long, your body can lose the ability to deliver insulin effectively. This puts you at risk for developing diabetes.
Diabetes in People with Cancer
For a person with diabetes, a cancer diagnosis and certain cancer treatments can affect diabetes control. In addition, it’s possible for a person diagnosed with cancer who did not previously have diabetes to develop secondary diabetes, a condition caused by elevated blood glucose due to cancer treatments. You are at higher risk of developing secondary diabetes if you are undergoing chemotherapy treatment, have had your pancreas removed, are using a feeding tube, or have taken high dosages of steroids. Other factors can contribute to high blood glucose as well, including the cancer itself, uncontrolled pain, decreased physical activity, and physical or emotional stress.
Sometimes a person who did not have diabetes prior to their cancer diagnosis will develop secondary diabetes, a condition caused by elevated blood glucose due to cancer treatments.
Signs and Symptoms of Diabetes
People with high blood glucose often experience excessive thirst, frequent urination, blurry vision, and sudden weight loss. If you’re receiving chemotherapy and begin to have these symptoms, you should tell your doctor and have your blood glucose level checked. If you have a history of diabetes, it is important to check your blood glucose level during chemotherapy and to alert your doctor if you develop these symptoms or if your blood glucose is elevated.
Risks and Complications
If you have diabetes and your blood glucose level is not controlled, you are at increased risk of heart attack, stroke, and other complications, such as kidney failure, blindness, the need for amputations, and nervous system damage.
If you have secondary diabetes, the short-term increase in blood glucose may not contribute to long-term complications. However, if your blood glucose level is high, your cancer treatment may have to be put on hold until your blood glucose is back under control. Short-term complications of secondary diabetes include infections and dehydration.
Dr. Victor Lavis
Treating, Managing, and Monitoring Diabetes
If you have diabetes, you need to have your cholesterol levels and blood pressure monitored. You should also undergo annual screening for diabetic eye and kidney disease.
Oral medications are available to treat diabetes, but you will need to take into consideration how their side effects might affect your cancer treatment. If your blood glucose level remains high despite the use of oral medications, you may be started on insulin therapy. This is usually temporary; however, some people may need to continue insulin therapy indefinitely to maintain good blood glucose control.
Your doctor may monitor your diabetes control through the hemoglobin A1C test. This blood test determines your average blood glucose level over a three-month period. But for some people, especially those who have recently received a blood transfusion, this test is ineffective. Therefore, it’s important to learn how to check your blood glucose level at home using a glucose meter. Your doctor may advise you to check your glucose level before or after meals, and will use this information to decide if any changes need to be made in your course of treatment.
You may also need to adjust your diet and activity level to help manage your blood glucose. Your doctor or nurse can give you more specific recommendations, but adopting these healthy habits can help keep your blood glucose level in check:
- Exercise at least 30 minutes a day.
- Eat a diet rich in fresh fruits and vegetables.
- Limit your carbohydrate intake.
- Decrease saturated fats in your diet.
- Avoid sugar-sweetened beverages.
Managing diabetes while living with cancer can be challenging. It requires coordination and communication among you and your healthcare team. But getting your diabetes under control is necessary for receiving the treatment you need for your cancer.
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Dr. Sonali Thosani is an assistant professor in the Department of Endocrine Neoplasia and Hormonal Disorders at the University of Texas MD Anderson Cancer Center in Houston, TX, with clinical interests in the management of steroid-induced hyper-glycemia in people with cancer. Dr. Victor Lavis is a professor in the Department of Endocrine Neoplasia and Hormonal Disorders at MD Anderson, with clinical interests in the management of diabetes and hyperglycemia in people with cancer.
Visit the American Diabetes Association website, diabetes.org, for more information about managing and monitoring diabetes, along with a variety of diabetes-friendly recipes and other resources.
This article was originally published in Coping® with Cancer magazine, January/February 2014.