In a lipid panel, which two tests are least affected by fasting?

In a lipid panel, total cholesterol and HDL cholesterol levels are generally less affected by fasting compared to other lipid measures like LDL cholesterol and triglycerides. When assessing lipid profiles, fasting is often emphasized primarily due to its significant impact on triglyceride levels, which can be elevated after meals, and LDL calculations that rely on triglyceride levels.

Total cholesterol, representing the sum of various types of cholesterol in the blood, tends to remain relatively stable regardless of the fasting state. Similarly, HDL cholesterol, known as "good" cholesterol, is not as influenced by immediate dietary intake. This is because HDL plays a key role in transporting cholesterol to the liver for excretion and is generally less responsive to short-term dietary changes.

In contrast, triglycerides are strongly affected by recent food intake and can spike postprandially (after eating). LDL cholesterol, while it is calculated based on the Friedewald formula (which includes triglycerides), can also be influenced by fasting, as an increase in triglycerides would affect the LDL calculation.

Thus, total cholesterol and HDL cholesterol are the two tests in a lipid panel that maintain more consistent results regardless of fasting, making the choice of these two tests the most accurate option.