Which equation corresponds to the De Long method for estimating VLDL in mg/dL?

• A. TAG/5
• B. TAG/6.5
• C. TAG/2.175
• D. TAG/2.825

Answer: (B)

Estimating VLDL-C from triglycerides uses a fixed conversion factor because VLDL particles carry triglycerides along with some cholesterol. In the classic Friedewald approach, VLDL-C is approximated as TG divided by 5. The De Long method, however, uses a different conversion: VLDL-C equals TG divided by 6.5. This adjusted divisor better reflects the actual cholesterol content carried by VLDL across typical adult ranges, especially when triglyceride levels vary or fasting status isn’t strict.

So, to apply the De Long method, you calculate VLDL-C as triglycerides divided by 6.5 mg/dL, and then LDL-C is obtained by subtracting HDL-C and this VLDL-C from total cholesterol.