Is Your New Meter Reading Higher?

Here’s Why Reference is Important

| Jan 1, 1999

People with diabetes have long been frustrated by variations in glucose meter readings. Now the meter industry has added a new wrinkle, meters that reference plasma rather than whole blood.

Plasma-calibrated meters give higher readings than those which are whole blood calibrated. Laboratory equipment also references plasma, which is why people who use whole-blood-referenced meters at home often are surprised when their laboratory HbA1c readings come back higher than they expected. Now some are getting those higher plasma readings at home.

What does this mean for self-care for people with diabetes? Experts say the first step is to verify the calibrations of their meters.

Plasma readings are about 12 percent higher than whole-blood readings. For example, the same blood sample would read 140 on a whole-blood and 157 on a plasma-referenced meter.

The key is to use either type of meter consistently, says June Biermann, coauthor of nine books on diabetes and publisher of the newsletter, The Diabetic Reader. People with diabetes use different meters during the day, but this becomes dangerous if one references plasma and the other whole blood. The difference in numbers could lead to incorrect insulin doses.

Read the Fine Print

LifeScan's FastTake meter caused confusion during the autumn of 1998 because it references plasma but many people did not know. Many LifeScan customers were accustomed to receiving whole-blood numbers from a One Touch, and the plasma numbers threw them off.

Either type of meter can be up to 20 percent off and still meet FDA standards. The danger comes from taking too much or too little insulin.

Here's an example of the danger of using two differently referenced meters, exacerbated by a 20-percent variation. This is a worst-case scenario, but it brings out the importance of knowing your meter.

With a whole-blood meter, the glucose level is 140, but if the meter is 20 percent too low, the meter reads 112. With the same blood sample, on a plasma meter, the level is 157, but if the meter is 20 percent too high, the reading is 188.

With a 188 reading before a meal, many would need supplemental insulin; with the 112 reading, extra insulin would not be necessary. You could be in danger of getting the wrong dose.

Both the 188 and the 112 readings are accurate readings. Some see this wide range as frustrating for self-care, but, as one industry insider says, a $50 instrument cannot be expected to perform like $150,000 lab equipment.

Is this really a big deal? Yes, say most experts, but knowledge can prevent mistakes. Use this page to check the calibrations of your meters, to make sure that all your meters are similarly referenced.

Click Here To View Or Post Comments

Categories: A1c Test, Diabetes, Insulin, Meters


Take the Diabetes Health Pump Survey
See What's Inside
Read this FREE issue now
For healthcare professionals only

You can view the current or previous issues of Diabetes Health online, in their entirety, anytime you want.
Click Here To View

See if you qualify for our free healthcare professional magazines. Click here to start your application for Pre-Diabetes Health, Diabetes Health Pharmacist and Diabetes Health Professional.

Learn More About the Professional Subscription

Free Diabetes Health e-Newsletter

Latest
Popular
Top Rated
Print | Email | Share | Comments (0)

You May Also Be Interested In...


Comments


Add your comments about this article below. You can add comments as a registered user or anonymously. If you choose to post anonymously your comments will be sent to our moderator for approval before they appear on this page. If you choose to post as a registered user your comments will appear instantly.

When voicing your views via the comment feature, please respect the Diabetes Health community by refraining from comments that could be considered offensive to other people. Diabetes Health reserves the right to remove comments when necessary to maintain the cordial voice of the diabetes community.

For your privacy and protection, we ask that you do not include personal details such as address or telephone number in any comments posted.

Don't have your Diabetes Health Username? Register now and add your comments to all our content.

Have Your Say...


Username: Password:
Comment:
©1991-2014 Diabetes Health | Home | Privacy | Press | Advertising | Help | Contact Us | Donate | Sitemap

Diabetes Health Medical Disclaimer

The information on this site is not intended or implied to be a substitute for professional medical advice, diagnosis or treatment. All content, including text, graphics, images, and information, contained on or available through this website is for general information purposes only. Opinions expressed here are the opinions of writers, contributors, and commentators, and are not necessarily those of Diabetes Health. Never disregard professional medical advice or delay seeking medical treatment because of something you have read on or accessed through this website.