Blood glucose monitoring is important for individuals managing diabetes. Regular testing provides information on how diet, exercise, and medication influence blood sugar levels throughout the day. This data helps individuals and healthcare providers make informed decisions to maintain target glucose ranges, crucial for overall health and avoiding long-term complications.
Expired Strips and Reading Accuracy
Expired blood glucose test strips lead to inaccurate readings, making them unreliable for monitoring blood sugar. While some believe expired strips consistently read lower, they can produce both lower and higher readings. The core issue is the unpredictability of the result, which can vary significantly depending on the strip’s condition and how long it has been expired. Healthcare professionals and regulatory bodies like the U.S. Food and Drug Administration (FDA) advise against using expired strips. Even strips nearing their expiration date may show inaccuracies, underscoring the importance of checking dates before use.
The Science Behind Strip Expiration
Blood glucose test strips function through a chemical reaction involving an enzyme, typically glucose oxidase or glucose dehydrogenase, coated on the strip’s surface. When a blood sample is applied, this enzyme reacts with glucose, generating an electrical current proportional to the glucose concentration. Over time, environmental factors like humidity, temperature, and light degrade these enzymes. This degradation reduces the enzyme’s activity, leading to a weaker reaction and an incorrect electrical signal, which can result in inaccurate readings. Exposure to air and moisture can accelerate this enzymatic breakdown, even before the printed expiration date.
Consequences of Using Expired Strips
Relying on inaccurate blood glucose readings from expired test strips carries serious health implications. If expired strips consistently yield falsely low readings, an individual might not administer enough insulin or delay treatment for actual high blood sugar (hyperglycemia). This can lead to severe conditions like diabetic ketoacidosis, a life-threatening medical emergency. Conversely, if expired strips produce falsely high readings, an individual might take too much insulin, resulting in dangerously low blood sugar (hypoglycemia). Mismanaging blood glucose levels based on unreliable data can lead to immediate complications and contribute to long-term health problems like nerve damage, cardiovascular disease, and vision issues.
Ensuring Accurate Glucose Monitoring
To ensure accurate blood glucose readings, always check the expiration date on test strip vials and discard expired ones. Proper storage is essential: keep strips in their original, tightly sealed container, away from extreme temperatures, high humidity, and direct sunlight. The ideal storage temperature is typically between 4°C to 30°C (39°F to 86°F), and strips should not be refrigerated. Regular quality control checks using a control solution, if recommended by the manufacturer, can help verify meter and strip accuracy. If there are concerns about meter accuracy or unusual readings, consulting a healthcare professional is advisable.