Updated: September 16, 2013
Check that strips are not outdated.
Check that control solution is not outdated. Use control solution with a strip (at least once per new bottle of strips, additional if you get unusual results with a blood sugar test). When you use a control solution, the result should be in the “Control Range”. If not, call the phone number on the back of the meter. Control Range in mg/dl in US, mmol/L in Europe and other areas.
WASH HANDS thoroughly. Why? Modern glucose meters use a very small amount of blood. Therefore any microscopic, unseen sugar-containing substance on the skin may have a large effect on blood sugar. Testing sugar after handling a banana peel has been shown to increase the blood sugar results significantly. Even hand lotion has been shown to change the blood sugar. If hand washing is not immediately available, a thorough cleansing with an alcohol pad is recommended.
CHECK CODE. Why? Some meters require coding. If the code on the strip bottle does not match the code on the meter, blood glucose (sugar) results will be inaccurate.
STRIP STORAGE. Strips should be stored with closed lid in the container they come in.
RECORD RESULTS. Why? Recording results allow you to see patterns. That allows you to adjust your lifestyle to improve control of diabetes. Do NOT change your medication without checking with your physician or diabetes team.
WHEN TO TEST. Your diabetes team will best determine when you should test. Some general rules: Test when you feel that sugar is low, you have a headache, develop shakes or feel different in any way. Re-test immediately if the sugar is unusually low or high. Ideally test before meals and 2 hours after the largest 2 meals. But there are large individual differences in testing need, consult your diabetes team.
ACCURACY. How accurate are glucose meters? “ Accuracy targets established by the International Organization for Standardization (www.iso.org) indicate that 95% of meter measurements should be within ±20% for glucose concentrations ≥ 75 mg/dL and within ± 15 mg/dL for levels <75 mg/dL." The U.S. Food and Drug Administration requires all meters to have an error rate of <20% of the reference value when glucose is >100 mg/dL and within 20 mg/dL when glucose is <100 mg/dL. Most major meter manufacturers meet ISO standards. Data from some of the newer meters (such as those with pharmacy and strip supplier brand names are difficult to find). We prefer meters by major players who provide meters with memory, download capacity with analytic data reports and automatically coded. In general those by Bayer, some by Roche and Abbott meet these criteria. LifeScan meters are very good but still require coding.
Sampling Blood Glucose (sugar).
Testing blood glucose is essential if one is to maintain a close watch on the progress of diabetes. This is especially important for those taking insulin, but also important for those with type 2 diabetes taking oral agents (pills). Remember, type 2 diabetes is progressive, no matter what is used to treat it, it gets worse. We often say to our patients with type 2, “whatever was working to control blood sugar 2 years ago, probably won’t be working now.” The frequency of testing is subject to controversy. Each person with diabetes should discuss this with the Health Care Provider or Diabetes Team. Our rules of thumb for people with stable diabetes are these:
Situations that might create a need to test more often.
CGM (Continuous Glucose Monitoring)
At the current state of research CGM measures glucose in the fluid beneath the skin (subcutaneous fluid). It has several advantages over glucose meter testing. One might consider the finger stick test a snapshot of the state of glucose here and now. The meter test however does not provide a complete pattern of the glucose changes even is the person is testing frequently.
In this example the person is testing four times daily. It appears that morning glucose is elevated but there is good control for the rest of the day.
When one looks at the wider picture with CGM it is obvious that glucose is sometimes very elevated in the morning and again in the evening, probably related to food intake. Continuous Glucose Monitoring can thus be used to adjust therapy to avoid unrecognized high and low glucose. Using CGM dose not take away the need to test with finger stick. All devices now available require finger stick blood sugar to calibrate the CGM device. Click here to see CGM devices.
BLOOD SUGAR LOGS, WHY BOTHER?
Many studies show that diabetes complications (kidney failure, amputation, heart attack, and stroke) can be prevented or delayed by good control of blood glucose (sugar). One also needs to control other risk factors such as blood pressure and cholesterol. It doesn’t matter HOW it is controlled as long as the control method itself is not harmful. In those of us requiring insulin, it is nearly impossible to gain control of blood glucose (sugar) without data collection.
In the “normal” person without diabetes, blood glucose is kept within a narrow range. This is done by the secretion of insulin in two fashions:
If the pancreas is not able to provide for these types of insulin, something must be done to help it along. In the person with Type 1 diabetes, both basal and bolus insulin will be required. In the person with type 2 diabetes, medication other than insulin may improve insulin secretion, help the response to insulin, reduce liver sugar production, slow stomach emptying, reduce carbohydrate absorption, etc. All of these require some internal insulin production to be effective. Eventually most people with type 2 diabetes will require insulin in some form.
In the insulin-requiring person with diabetes (type 1 or type 2), the collection of blood sugar information is crucial for insulin dose adjustment to gain control. Somehow basal insulin needs (e.g. Lantus®, Levemir®) must be established (we generally estimate this based on body weight) and bolus insulin must be matched to blood glucose (sugar) and food intake. Below is a example of a form we use to collect information.
In this example several things become obvious:
This example only shows one day. We like to see several days before making changes,
Designed and Copyright by Charles H. Raine, III, M.D.