Certified Diabetes Care and Education Specialist (CDCES) Practice Exam

When should alternate site testing (AST) be avoided in persons at risk for hypoglycemia?

1. In persons using insulin sensitizers

2. When the glucose is likely to change rapidly

3. Before meals

4. 2 hours after meals

The correct answer is: When the glucose is likely to change rapidly

Alternate site testing (AST) should be avoided when the glucose levels are likely to change rapidly because these alternative sites, such as the forearm or thigh, may not reflect the immediate changes in blood glucose as accurately as fingertip testing. This is particularly important for individuals at risk for hypoglycemia, as they need timely and precise information about their glucose levels to prevent severe hypoglycemic events. Rapid fluctuations in blood glucose can occur after eating, during exercise, or when adjusting insulin doses, and testing at alternative sites during these times might provide misleading results. Fingerstick testing gives a more accurate real-time reading, which is crucial for making immediate decisions regarding food intake, carbohydrate consumption, or insulin administration. In contrast, the other scenarios, such as using insulin sensitizers, testing before meals, or testing 2 hours after meals, are less directly related to the immediate risk of hypoglycemia. Individuals can still monitor their glucose levels effectively with AST in those situations since fluctuations are typically not as rapid compared to times of insulin adjustment or after physical exertion.