Final answer:
Patient samples are drawn in the early morning because patients will be in a fasting or basal state, which is crucial for accurate testing of blood glucose levels and long-term glucose management through tests like A1C.
Step-by-step explanation:
The best reason why the majority of patient samples are drawn in the early morning hours is because the patient will be in the basal state, having refrained from strenuous exercise and having fasted for approximately 12 hours. This fasting state ensures that tests such as blood glucose levels and endocrine functions can be assessed accurately. For example, in the diagnosis of diabetes mellitus, fasting allows for a clear understanding of how the pancreas responds to sugar intake, where normally, the blood glucose level will return to normal after the sugar drink is consumed. If not, it indicates a potential for diabetes mellitus. Similarly, in the case of the A1C test, which measures long-term glucose management, having a baseline fasting blood sample is essential for accurate results.