Final answer:
A 4-hour delay in testing blood glucose levels collected in a gray tube maintained with sodium fluoride can lead to lower glucose levels due to the gradual weakening of sodium fluoride's inhibitory effect on glucose oxidation.
Step-by-step explanation:
A 4-hour delay in testing blood glucose levels collected in a gray tube maintained with sodium fluoride will likely result in lower glucose levels compared to the actual levels. Sodium fluoride is added to blood samples to inhibit enolase and prevent oxidation of glucose by erythrocytes and leukocytes. However, over time, the sodium fluoride's inhibitory effect may weaken, leading to gradual glucose oxidation and a decrease in blood glucose levels.
Thus, a 4-hour delay in testing can lead to inaccurate glucose level measurements, with lower values observed. It is important to analyze blood samples promptly after collection when using a gray tube maintained with sodium fluoride to obtain reliable results.
Remember, the effect of the delay may vary depending on several factors, so it is always best to consult a healthcare professional for accurate and specific guidance.