Testing For CFRD
If you have been diagnosed with CF-related diabetes, this will likely affect your day-to-day living as you will need to be aware of the foods that you eat, monitor your sugars, and take insulin to help manage your blood sugars. Read more about why people with CF can develop CFRD by checking out our endocrine pancreatic function section.
We believe that aggressive and early replacement of insulin can improve lung function, increase muscle mass, stop weight loss, and help people with CF related diabetes to live longer, healthier lives. Once a year you will be tested for diabetes with a screening blood test (HbA1C) or an oral glucose tolerance test (OGTT).
As most people know, the oral glucose tolerance test (OGTT) is a regular part of your yearly tests. To have an OGTT you must be fasting. This means nothing to eat or drink other than water for 12 hours before the test. The test takes 2 hours. Your blood sugar is measured and then you are asked to drink a sugar-drink. Your blood sugar is then tested again 2 hours after the drink. Two hours is the normal amount of time the body should take to absorb the sugar into your cells from your bloodstream. In a healthy body, insulin is released from the pancreas in response to the high sugar load, which triggers the absorption of sugar out of the blood and into the cells.
A high level of sugar in the blood tells us that the cells in the body have not absorbed enough of the sugar and there is impaired glucose tolerance, or diabetes. It is best to have the test done at a time when you are not sick, since illness can affect your body’s ability to efficiently use insulin. If you are booked for an OGTT and are unwell, please call the clinic ahead of time so the test can be re-scheduled. Also, if you have symptoms of diabetes, are pregnant, or are on oral steroids (prednisone) we may do the test more often because these situations place you at higher risk for developing diabetes.
Within this section, you will learn the various ways that you can monitor your sugars, what is an optimal blood sugar range, how to carbohydrate count, the impact of CFRD on nutrition, pregnancy, and post-transplant among other things.
Monitoring Blood Sugars
These devices provide excellent medical and lifestyle benefits. People can now see in real-time the effects of food and exercise on your blood glucose levels, and can catch cases of high and low blood sugars as they happen, avoiding the potentially dangerous consequences. CGM and FGMs can essentially eliminate the need for those regular fingerstick tests, the long-standing only way to check blood sugar levels. Additionally, most CGMs can send alerts telling you when your blood sugar levels are rising too high or dropping too low. You can also set the alert parameters, customize how you are notified, and share data with both family members and your diabetes care team.
If you are interested in learning more about these devices, please contact your CF Diabetes Educators.
Carbohydrate Counting & CFRD
Carbohydrate counting is a meal planning method for people with diabetes.The amount of carbohydrate in foods is one of the factors that affect blood sugar levels (stress, activity, alcohol and illness do also). Counting carbohydrates allows you to add flexibility to your food choices without compromising your blood sugar control. At first, it takes a little work (record keeping) but many people find the results worth the effort.
Experience helping others with diabetes has taught us a few tricks that might help you. It is very important that you DO NOT cut down on the amount of food that you eat in order to try and control your blood sugar levels! You still need to follow your usual high-calorie, high fat diet (with NO restrictions on carbohydrates or sugars) to help you achieve and maintain a healthy body weight. Monitoring your blood sugars and taking the correct amount of insulin will help you to maintain your weight and stay healthy!
More information on how to carbohydrate count can be found here.
Insulin Therapy for CFRD
When someone is diagnosed with CF related diabetes, we will ask you to monitor your blood sugars for two weeks consecutively (see blood sugar monitoring in an above section), and based on your blood sugar results you CF team may start you on insulin therapy. There are many different types of insulin therapy depending on your unique blood sugar pattern. Your healthcare team will work with you to determine which insulin type is best for you. Insulin is given via sub-cutaneous injection. Usually people are started on multiple injections per day but in time, it may be possible to switch to an insulin pump.
Nutrition & CFRD
To ensure good health, it is important to maintain a healthy body weight. With other types of diabetes, people are often told to eat a low-fat, low-salt and sometimes low-calorie diet. People living with CF-related diabetes still need the normal high-calorie, high-protein, high-fat, high-salt “CF diet” to help you achieve and maintain a healthy weight. Keeping your blood sugar at near-normal levels will help to maintain your weight and ensure good health.
The main change in terms of your diet when you have CF-related diabetes is learning how to measure or identify the foods that affect your blood sugars the most and adjust your insulin accordingly. It is still important to eat a well-balanced meal from all the food groups in addition to consuming extra fats and sweets for more calories.
Carbohydrates have the most effect on blood sugar levels as they are broken down into sugars that are absorbed into the blood. Protein and fats do not raise blood sugar levels but they are important as they can slow down the absorption of sugars which can help to stabilize sugar levels in the blood. The main way to control your blood sugar is to control the amount of carbohydrates in your meals/snacks. You should not avoid carbohydrates as they are an important component of weight gain. This means that foods that are sweet, including desserts, are all part of a balanced diet, even when you have diabetes. This is very different from people who have diabetes that is not related to CF. To learn how to manage your carbohydrates with CF-related diabetes your CF dietitian can help develop a plan that works best for your lifestyle.
See the Carbohydrate Counting content above or download our Insulin and Snacking document for additional information.
Pregnancy & CFRD
If you are considering pregnancy, you will need to do an oral glucose tolerance test (OGTT). Diabetes during pregnancy is more common in women with CF. The OGTT will need to be repeated once pregnancy is confirmed and then again in the 2nd and 3rd trimesters. Untreated diabetes may lead to a loss in energy, weight, and increase your risk for illnesses. It can also have harmful effects on your baby. If you have diabetes, monitoring your blood sugar is necessary so that you can achieve optimal sugar control prior to pregnancy. The target blood sugar values are different in pregnancy so make sure you review this with your CF team. After your delivery, your sugars should be re-checked within 6-8 weeks post-partum to ensure that they have returned to normal.
Lung Transplantation and CFRD
The chance of developing diabetes after transplant is high for two reasons: people with CF have a higher chance of developing diabetes and the steroids prescribed after transplant can cause high blood sugars. If you already have diabetes, continue to monitor your blood sugars and adjust your insulin dose with the help of your medical team. Be sure to check your blood sugar level approximately 6-8 hours after you take your prednisone dose. If you did not have diabetes before transplant, your blood sugar level will be checked as part of your transplant bloodwork. It is important for you to self-monitor your blood sugar levels approximately two hours after your meals. Also, watch for the following symptoms and let your transplant team know if you experience them:
- Unexplained weight loss
- Feeling more tired
- Feeling very thirsty
- Change in appetite
- Urinating more often
- Blurry vision
- Skin infections
- Wounds or sores that do not heal easily
If you want more information on this topic speak with our dietitians or your medical team.
Impaired Glucose Tolerance
Impaired Glucose Tolerance (IGT) can be detected with an oral glucose tolerance test (OGTT). This test is typically done each year and blood is taken before and 2 hours after having a sugary drink. The fasting blood sugar is normal but the blood sugar at the 2-hour mark is higher than expected, but not high enough to say someone has diabetes. In this circumstance, your body is making insulin but it is not working as efficiently and/or making as much as it should. Sometimes this can happen during times of stress such as during a chest infection