What reflects the extent of glucose regulation over the 8- to 12-week interval prior to sampling?

Glycated Hemoglobin (G-Hgb), also known as HbA1c, is a key marker that reflects the average blood glucose levels over the past 8 to 12 weeks. It is formed when glucose in the blood binds to hemoglobin, and since red blood cells typically have a lifespan of about 120 days, the level of HbA1c provides a long-term indicator of glucose control. This makes it especially useful for monitoring diabetes management and assessing how well blood sugar levels have been maintained over time.

The immediate blood glucose levels provide a snapshot of glucose at a single point in time and do not give information about the average levels over weeks. The fructosamine assay measures glycated proteins and reflects glucose levels over a shorter period, typically 2-3 weeks, which is not suitable for long-term monitoring like HbA1c. Fasting insulin levels help assess insulin production and sensitivity but do not directly indicate glucose regulation in the way that HbA1c does. Thus, Glycated Hemoglobin is the most appropriate choice for evaluating glucose regulation over the extended timeframe mentioned.