Comparison of the accuracy of the Friedewald, Martin, and Sampson formulas to estimate very low levels of low-density lipoprotein cholesterol.

FF was the most inaccurate formula to estimate very low LDL-C. Despite MF and SF showing better results, their frequency in underestimating LDL-C was still considerable. In patients with falsely low estimated LDL-C, apoB and non-HDL-C were significantly higher, reflecting its true high atherogenic burden.