Blood Sugar and Ketone Meters

Blood Sugar Meters That Do Double Work with Blood Ketones

diabetes test strips for glucose and ketones
Blood sugar meters that also test blood ketones are an effective way of managing diabetes. Saturn Stills/Science Photo Library/Getty Images

In addition to testing blood glucose, meters are also available to provide the ability to test blood ketones. It is particularly important to test for ketones during periods of illness. Traditionally, ketones have been measured with urine strips, but the American Diabetes Association now recommends blood ketone testing as the more accurate, timely, and preferable method for detecting ketones.

You should discuss home blood ketone testing with your doctor to learn whether it is recommended in your case and when you should perform the testing.

(Later on we will review the importance of testing for ketones and what it means for you.)

Urine Ketone Strips vs. Blood Ketone Testing

In addition to being less accurate overall, urine ketone testing has other drawbacks. Whereas blood ketone testing helps you know what is happening in your blood right now, urine ketone testing only lets you know what was going on in your blood several hours earlier—it takes time for the kidneys to filter your blood before evidence of ketones show up in your urine.

Urine ketone test strips also frequently lose their accuracy when the bottle has been open for weeks or months, leading to misleading results. Urine ketone test strips should always be used within six months of opening the bottle.

Urine ketone test strips test for the presence of acetoacetic acid in urine, whereas blood ketone test strips test for beta-hydroxybutyrate. It's been shown that beta-hydroxybutyrate is a better indicator of what is happening metabolically in the body of someone with diabetes than acetoacetic acid.

Urine ketone test strips can give false readings if the urine is highly acidic, or in those who are taking some medications such as captopril. Finally, people—especially when dehydrated—may not be able to urinate to provide a specimen to test. Since it is in the setting of illness when a ketone level is most important, this is an obvious advantage of blood ketone testing.

How Does Blood Ketone Monitoring Work?

In order to monitor your blood ketones, you need separate ketone test strips. Glucose test strips cannot be used in these meters to monitor for blood ketones. Current blood ketone test strips are approved for home use with fresh whole blood obtained from the fingertip. Alternate sites are not approved for ketone testing. The following article reviews how to test your blood for ketones.

Blood Ketone and Glucose Meters for Testing at Home

The chart below lists the glucose meters that measure blood glucose and blood ketones, along with some other important features that may be of interest to you. Both are available for sale online and from major retailers. The meters themselves are inexpensive but the strips can be a large ongoing expense.

Precision Xtra: This meter from Abbott has a memory that can store up to 450 measurements and it displays your blood glucose average results for the past week, two weeks and month. You can also download your results to a computer with data management software.

Nova Max Plus: The meter is often provided free with the purchase two boxes of test strips (glucose, ketone, or both). It will remind you to test for ketones if your blood sugar level is 250 mg/dL or higher. It doesn't require entering a code to switch it from blood glucose to ketone testing. You simply insert the ketone test strip.

Meters That Measure Blood Glucose and Blood Ketones

MeterResults storedBlood sampleComputer downloadBacklit displayCoding neededCompany
Precision Xtra4501.5 microliterYesYesYesAbbott Diabetes Care
Nova Max Plus4000.3 microliterYesNoNoNova Biomedical

Features to Consider When Buying a Blood Glucose and Ketone Testing Equipment

As with most technology equipment, blood sugar testing monitors vary in many ways. Some of the features aren't good or bad—they are simply features that some people may like but that others will find irrelevant or even a nuisance. Some of these features include:

What Exactly are Ketones?

When there isn't enough glucose available to meet the metabolic needs of cells—such as when insulin levels are too high—the body breaks down fats into fatty acids instead to obtain an alternate energy source.

If there is an adequate amount of something called oxalacetone, the fatty acids enter a process called the Kreb's cycle which results in the production of energy. If there is not enough oxalacetone present, the result is the production of ketone bodies. Ketone bodies are acids, namely acetoacetic acid and beta-hydroxybutyrate.

These ketone bodies (acid) lower the pH (acidity of the blood.) In an acidic environment, the enzymes in our bodies which are responsible for a vast number of functions do not work. These affects, called diabetic ketoacidosis (DKA) are a medical emergency.

Importance of Ketone Testing with Diabetes

Studies have found that blood ketone monitoring is effective in decreasing emergency room visits, hospitalizations and improves the time to recovery in people who do develop diabetic ketoacidosis.

When Should You Check for Ketones?

There are several settings in which blood ketone testing is recommended. These can include:

  • If your blood sugar is over 250
  • If you are feeling ill, for example, if you have symptoms of a cold or the flu, experience any nausea or vomiting, or feel more tired than usual
  • If you believe you may be dehydrated
  • Blood ketones can also be an indicator that your blood sugar has dropped too low while you have been sleeping

Evaluating Your Blood Ketone Results

It is important to learn how to read your blood ketone results. Since everyone is different, make sure to talk to your endocrinologist about how to read your levels and when you should call. In general, a level of 0.6 mmol/L up to 1.0 mmol/L is considered normal. If your level is between 1.0 and 1.5 mmol/L you should call your doctor, but make sure to talk to your doctor because these guidelines may be different depending on how brittle your diabetes is and other factors. Between 1.5 and 3.0 mmol/L you should call your doctor right away, and be aware that you are at risk for ketoacidosis. If you have a ketone level over 3.0 mmol/L you should head to the emergency room right away or call 911 if needed.

Bottom Line on Combination Blood Glucose and Ketone Meters

It's becoming clear that monitoring blood ketone levels when at risk (with illness or any other conditions as recommended by your endocrinologist) can lower your risk of hospitalization and complications of diabetes such as ketoacidosis. Make sure to learn how to test your blood and interpret the results before you experience the need to test (such as during an illness) so you are readily familiar with the process. Different meters have different advantages and disadvantages for different people, but the important point is simply to find a meter that you can use easily and follow guidelines for testing.

Sources:

Klocker, A., Phelan, J., Twigg, S., and M. Craig. Blood β-Hydroxybutyrate vs. Urine Acetoacetate Testing for the Prevention and Management of Ketoacidosis in Type 1 Diabetes: A Systematic Review. Diabetic Medicine. 2013. 30(7):818-24.

Misra, S., and N. Oliver. Utility of Ketone Measurement in the Prevention, Diagnosis and Management of Diabetic Ketoacidosis. Diabetic Medicine. 2015. 32(1):14-23.

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