When managing blood sugar, a common question arises regarding the reliability of glucose test strips once they pass their expiration date. Understanding the science behind test strip expiration is important for effective self-monitoring.
Why Test Strips Expire
Glucose test strips are designed with specific chemical components that react with glucose in a blood sample. These strips contain enzymes, such as glucose oxidase or glucose dehydrogenase, and other chemical reagents. When blood is applied, these enzymes facilitate a reaction that generates an electrical signal, which the glucose meter interprets to display a blood sugar level.
Over time, these delicate chemical and enzymatic components degrade and lose stability. Environmental factors like humidity, heat, and light can accelerate this degradation. Manufacturers establish expiration dates through rigorous testing, confirming accuracy only up to that point.
How Accuracy is Compromised
The degradation of chemical reagents and enzymes on expired test strips directly impacts their ability to accurately detect and quantify glucose levels. When these active ingredients break down, the chemical reaction necessary for a precise reading becomes unreliable. This can lead to readings that are falsely high, falsely low, or simply erratic and inconsistent.
Users cannot determine the exact degree or direction of inaccuracy without a laboratory comparison. The strip’s compromised integrity prevents it from generating the correct electrical signal the meter relies upon. Consequently, any results from expired strips are untrustworthy for making informed health decisions.
Health Risks of Unreliable Readings
Using expired glucose test strips carries significant health risks due to inaccurate blood sugar readings. Incorrect readings can lead to inappropriate treatment decisions with serious consequences. For instance, a falsely low glucose reading might prompt insufficient insulin or medication, leading to hyperglycemia (dangerously high blood sugar).
Conversely, a falsely high reading could cause an individual to administer too much insulin or medication, resulting in hypoglycemia (dangerously low blood sugar). Both hyperglycemia and hypoglycemia can lead to medical emergencies if not properly managed. Relying on unreliable results compromises effective diabetes management and can lead to severe complications like diabetic coma or ketoacidosis.
Best Practices for Test Strip Management
To ensure reliable blood glucose monitoring, always verify the expiration date on the test strip vial or box before use. Expired strips should be discarded, as their accuracy cannot be guaranteed. Proper storage is also essential to maintain strip integrity.
Store test strips in their original, tightly sealed container, away from direct sunlight, extreme temperatures, and moisture. High humidity and excessive heat accelerate the degradation of delicate chemicals within the strips. Purchasing new, in-date strips from reliable sources and avoiding bulk purchases that might lead to unused, expired supplies helps ensure consistent and accurate readings.