- Use caution if blood glucose levels are greater than 300 mg/dl and ketones are not present.
If your blood glucose level is higher than 250 mg/dl, you do not have ketones in your blood or urine, and you want to exercise, I recommend starting your workout then stopping after 15 minutes to see if your blood glucose level is rising or dropping. If it’s dropping, it’s OK to continue exercising. If it’s rising, you should stop exercising and follow your doctor’s recommendations for treating high blood glucose.
As stated earlier, for most people, ketones are nothing to worry about. But when you have diabetes, particularly Type 1 diabetes, it may be a signal that your diabetes is out of control. Your body may make ketones when you are sick, have an infection, are injured, or are experiencing high levels of stress. They can appear in your urine (ketonuria) and in your blood (ketonemia).
The problem with high levels of ketones is that they are relatively strong acids, and because of their acidity, their presence in the blood can reduce the ability of oxygen to bind to hemoglobin, the molecule that transports oxygen to cells that need it. That means muscles and other organs might not function as well as they should. In addition, high levels of ketones for people with Type 1 diabetes can lead to dehydration and diabetic ketoacidosis (sometimes called DKA). Diabetic ketoacidosis is rarely seen in people with Type 2 diabetes because their pancreases usually still produce some insulin, which means that the body is able to burn some glucose.
Testing for ketones
People with Type 1 diabetes have most likely been asked by a doctor or diabetes educator to test their urine for ketones at one time or another. The development of the Precision Xtra meter has also made it possible to check blood levels of ketones at home. Two other home analyzers, the CardioChek and the CardioChek/PA (which also measure blood cholesterol levels), can also measure blood ketone levels. It’s a good idea to review ketone testing guidelines with your doctor or diabetes educator, but here are some general guidelines for who should test and when:
- People with Type 1 diabetes whose blood glucose level is over 250 mg/dl for two readings in a row or who are sick should always test for ketones.
- Pregnant women with diabetes are usually advised to check their urine for ketones every morning before eating and additionally if their blood glucose level is above 200 mg/dl or if they are ill.
- Most adults with Type 2 diabetes don’t need to worry about ketones, but check with your doctor or diabetes educator for specific instructions.
- Most of the time, children with Type 2 diabetes don’t need to check for ketones, but ask your doctor, especially if your child experiences unexplained weight loss or his blood glucose level consistently remains over 200 mg/dl.
Ketones are usually tested with urine test strips, which change color based on the presence and concentration of ketones in the urine. The results are usually expressed as “negative,” “trace,” “small,” “moderate,” or “large.” If the test result is positive, you should call your doctor or diabetes educator. You may need to take extra insulin, and your health-care provider will instruct you on how much. You should also drink lots of water or other calorie-free beverages to flush out excess ketones, continue to check your blood glucose level every three hours, and continue to test for ketones if your blood glucose level is over 250 mg/dl.
If you are losing weight, you may have a small amount of ketones in your urine. This is OK for people with Type 2 diabetes, as long as their blood glucose level is in a normal range, but people with Type 1 diabetes should check with their doctor. The mild ketosis (the presence of small amounts of ketones in the body) that occurs in people on low-carbohydrate diets should not be confused with the life-threatening levels of ketosis that someone who has Type 1 diabetes can develop. Diabetic ketoacidosis is a serious medical emergency that requires immediate medical attention.