Is calculated Apolipoprotein B value a reliable surrogate of its true serum value? Comparison of four equations

Background: The determination of apolipoproteinu B100(ApoB) is complementary to the low-density lipoprotein cholesterolin the cardiovascular risk estimation. ApoB is rarelymeasured with standard lipids in the evaluation of dyslipidemia.Recently have been published several formulas to calculateApoB from standard lipids. Patients and methods: We compared the measured ApoB(ApoBdir) with four equations to calculate ApoB authors Cho(ApoBCho) Hermans (ApoBHermans), Hwang (ApoBHwang)and Kulkarni (ApoBKulkarni), from the three independent seriesof patients defined differently from clinics in Košice,Bratislava and Olomouc. Results: Concordance correlation coefficient (CCC) forApoBCho for three sets ranged from 0.516 to 0.765; forApoBHermans 0.571 to 0.672; for ApoBHwang from 0.621 to0.778; for ApoBKulkarni 0.536 to 0.715. In each set had thehighest value CCC ApoBHwang. Hwang equation were modifiedby the addition of constants for each file different so thatthe difference between means and ApoB calculated ApoBdirwas 0 %. For modified equation Hwang the lowest CCC valuewas 0.793 (95% CI 0.729 to 0.844) for dataset Bratislava andhighest value of 0.923 (95% CI 0.912 to 0.934) for datasetOlomouc, and 0.918 (95% CI 0.908 to 0.928) for dataset Košice. Conclusion: The modified equation Hwang seems to be suitablefor use in clinical epidemiology and routine clinical practice.