Developing a modified low-density lipoprotein (M-LDL-C) Friedewald’s equation as a substitute for direct LDL-C measure in a Ghanaian population: a comparative study

Despite the availability of several homogenous LDL-C assays, calculated Friedewald\u27s LDL-C equation remains the widely used formula in clinical practice. Several novel formulas developed in different populations have been reported to outperform the Friedewald formula. This study validated the existing LDL-C formulas and derived a modified LDL-C formula specific to a Ghanaian population. In this comparative study, we recruited 1518 participants, derived a new modified Friedewald\u27s LDL-C (M-LDL-C) equation, evaluated LDL-C by Friedewald\u27s formula (F-LDL-C), Martin\u27s formula (N-LDL-C), Anandaraja\u27s formula (A-LDL-C), and compared them to direct measurement of LDL-C (D-LDL-C). The mean D-LDL-C (2.47±0.71 mmol/L) was significantly lower compared to F-LDL-C (2.76±1.05 mmol/L), N-LDL-C (2.74±1.04 mmol/L), A-LDL-C (2.99±1.02 mmol/L), and M-LDL-C (2.97±1.08 mmol/L) p \u3c 0.001. There was a significantly positive correlation between D-LDL-C and A-LDL-C (r=0.658, p\u3c0.0001), N-LDL-C (r=0.693, p\u3c0.0001), and M-LDL-C (r=0.693, p\u3c0.0001). M-LDL-c yielded a better diagnostic performance [(area under the curve (AUC)=0.81; sensitivity (SE) (60%) and specificity (SP) (88%)] followed by N-LDL-C [(AUC=0.81; SE (63%) and SP (85%)], F-LDL-C [(AUC=0.80; SE (63%) and SP (84%)], and A-LDL-C (AUC=0.77; SE (68%) and SP (78%)] using D-LDL-C as gold standard. Bland-Altman plots showed a definite agreement between means and differences of D-LDL-C and the calculated formulas with 95% of values lying within ±0.50 SD limits. The modified LDL-C (M-LDL-C) formula derived by this study yielded a better diagnostic accuracy compared to A-LDL-C and F-LDL-C equations and thus could serve as a substitute for D-LDL-C and F-LDL-C equations in the Ghanaian population