Which statement correctly defines non-HDL-C and its components?

• A. Non-HDL-C equals total cholesterol minus LDL-C; includes HDL and VLDL.
• B. Non-HDL-C equals total cholesterol minus HDL-C; includes LDL, VLDL, IDL.
• C. Non-HDL-C equals LDL-C plus HDL-C; includes all lipoproteins.
• D. Non-HDL-C equals HDL-C minus LDL-C; includes only LDL.

Answer: (B)

Non-HDL-C represents the cholesterol content in all atherogenic lipoproteins, which are everything except HDL. It is calculated as total cholesterol minus HDL-C. This leaves the cholesterol carried by LDL, VLDL, IDL, and other remnants (including Lp(a) in some assays). This is why the statement that total cholesterol minus HDL-C equals non-HDL-C and includes LDL, VLDL, and IDL is correct. Subtracting LDL-C or subtracting HDL-C from the wrong base, or combining HDL with LDL, would not accurately define non-HDL-C, so those alternatives don’t fit. This measure is especially useful when triglycerides are elevated, because it accounts for all apoB-containing lipoproteins involved in atherogenesis.