Maintaining healthy blood sugar levels is fundamental to overall metabolic health and preventing chronic conditions like type 2 diabetes. Blood sugar, or glucose, is your body's primary source of energy, derived from the foods you eat. The tests discussed in this chapter provide insights into how effectively your body processes and utilizes glucose, and how well it manages insulin.
Glucose (fasting blood sugar) is a direct measurement of the amount of sugar in your blood after an overnight fast (typically 8-12 hours). A fasting glucose test is a common screening tool for diabetes and prediabetes. Consistently elevated fasting glucose levels can indicate insulin resistance or diabetes. It's important to note that even a single elevated reading warrants further investigation, as early detection and lifestyle interventions can significantly impact long-term health outcomes.
Hemoglobin A1c (HbA1c) provides an average picture of your blood sugar levels over the past two to three months. Unlike a fasting glucose test, which is a snapshot, HbA1c reflects how much glucose has attached to your red blood cells over their lifespan. This test is invaluable for diagnosing diabetes and prediabetes, as well as for monitoring blood sugar control in individuals already diagnosed with diabetes.
Insulin levels can also be measured, though less commonly as a routine screening. Insulin is the hormone produced by the pancreas that helps glucose enter your cells for energy. High insulin levels, especially in the presence of normal or slightly elevated blood sugar, can be a sign of insulin resistance, a precursor to type 2 diabetes.