Blood Glucose Monitoring
Why self-test blood glucose levels?
Testing enables you to see how certain foods, activities, and situations may impact your blood glucose levels. It can also help you and your diabetes care team evaluate how effective, or ineffective, a new treatment routine or change in medication is. For people who take insulin, self-testing allows for more accurate dosage adjustments.
The ADA suggests that people taking multiple insulin injections or using insulin pump therapy, such as those with type 1 diabetes and some pregnant women, and people with type 2 diabetes who take multiple injections of insulin daily should test three or more times daily. There is no official recommendation for daily testing frequency for those with type 2 diabetes who are on oral medication or who control their diabetes through diet and exercise only; however the ADA does state self-monitoring of blood glucose may be appropriate in order to achieve blood glucose targets.1
What kind of blood glucose monitor?
There are a wide variety of blood glucose monitors to choose from, from stripped down single-reading meters to models with computer compatibility, alarms, and backlights. Think about the functions that are important to you. For example, if you like seeing trend data on your glucose readings, a meter that has extensive memory may be for you. People with vision impairment may prefer a large display, or an adaptive meter with voice reading capabilities. Size may also matter; if you prefer an unobtrusive glucose monitor that can be used discretely you’ll want something small and easy to handle. Your certified diabetes educator or pharmacist is a good source of information on what blood glucose monitor may be right for you.
Most meters on the market today read blood plasma, the same standard that is used in a clinical setting (many older meters provide whole blood readings). Consider the following features when deciding on a blood glucose monitor:
- Size and user-friendliness. Is it convenient for your needs and easy-to-use?
- Time to readout. How long does the meter take to display results?
- Memory. How many test results will the meter’s memory hold, and does it have the capability of averaging results for a designated time period?
- Trend data and computer compatibility. Does the meter interface with a computer and allow you to download meter results and generate blood glucose trend information?
- Battery life and availability. Will battery power last a reasonable amount of time, and are the batteries easily available at a local store or must they be special ordered?
- Blood sample size. Does the meter require a minimal amount of blood, or do you have to open a vein to get a reading?
- Alternative site testing. Some meters allow you to test blood samples from the forearm and other sites beyond the fingertips.
- Cost. Factor in the cost of test strips when evaluating your meter purchase.
- Multitasking. Some blood glucose monitors double as blood ketone testers (Precision Xtra; Abbott Diabetes Care).
- Adaptive technology. If you have vision impairments, you may need a meter that “speaks” your results.
- Bells and whistles. Glow-in-the-dark cases, backlighting, and swappable faceplates are just a few of the other features today’s blood glucose meters can offer.
What other supplies do you need?
All meters require test strips to operate—a small chemically treated strip that slides into the meter. After insertion, a drop of blood is placed on the opposite end of the strip that protrudes from the meter, and the meter reads the glucose level and displays the number on the screen.
Some monitors use test strip drums, which are self-enclosed spools of strips that automatically load without user intervention. Small children and adults who have difficulties with their fine motor skills may find this type of monitor easier to use.
You’ll also need a lancet (a small, fine needle) to get a blood sample for testing. Lancets are inserted into a lancet device—a spring-loaded mechanism about the size and shape of a pen. A dial allows the user to adjust the depth of the lancet stick. Typically there is a button that you push to release the lancet into a fingertip or other site to draw a blood sample. Lancets come in different gauges; the higher the gauge, the finer (i.e., thinner) the needle. Higher gauge needles are less painful, but they also may create a smaller blood sample.
Your blood glucose monitor may also come with control solution (for calibrating the monitor per manufacturer’s directions for use) and a carrying case.
SOURCES:1 - American Diabetes Association. ADA Standards of Medical Care in Diabetes—2008. Diabetes Care, Volume 31, Supplement 1, January 2008. (PDF accessed 2/19/08).
Reviewed by Francine Kaufman, MD. 4/08