Contents lists available at ScienceDirect Clinical Biochemistry journal homepage: www.elsevier.com/locate/clinbiochem Short Communication Impact of the Martin/Hopkins modified equation for estimating LDL-C on lipid target attainment in a high risk patient population Louis-Jacques Cartier a, ⁎ , Simon St-Coeur a , Alex Robin a , Mathieu Lagace a , Pierre Douville b a The Moncton Hospital, Horizon Health Network, NB, Canada b Centre Hospitalier Universitaire de Québec, Québec, QC, Canada ARTICLE INFO Keywords: Lipid profile Diabetes Martin/Hopkins equation Estimation of LDL-C ABSTRACT Objective: To evaluate the Martin/Hopkins equation for estimating LDL-C as target in a population composed of high cardiac risk patients. Methods: Lipid profile data from patients with TG ≤ 4.52 mmol/L (< 400 mg/dl) were used. The high cardiac risk group (N 4150) consisted of patients over 40 years of age that had an A1C level of 6.5% or above and patients with a history of atherosclerotic cardiovascular disease (ASCVD). Comparisons were made between the Martin/Hopkins formula (MH-LDL-C), the Friedewald formula (F-LDL-C), Non-HDL-C and ApoB. Results: Higher LDL-C values (0.15 mmol/L or 7.3%) were obtained using MH-LDL-C compared to the F-LDL-C. The % within target (%WT) values for F-LDL-C, MH-LDL-C, Non-HDL-C and ApoB were similar when TG levels were ≤ 1.5 mmol/L with a high degree of concordance as measured by the kappa statistic. When compared to F- LDL-C, Non-HDL-C and ApoB showed a profound decrease in the WT value as TG levels increased from normal (67.7%) to intermediate (39.1%) and high levels (20.8%). MH-LDL-C showed an attenuated decrease in the WT value as TG increased from normal (61.4%) intermediate (43.4%) and high levels (32.7%). Concordance with the alternate target parameters was higher for MH-LDL-C than for F-LDL-C when triglycerides levels were in- creased. Conclusion: The Martin/Hopkins modified equation for estimating LDL-C is a significant improvement on the decade’s old Friedewald formula; however it remains an imperfect tool to estimate the atherogenic load in patients with high TG levels. 1. Introduction It is increasingly recognized that the estimation of LDL-C by the Friedewald formula is problematic in patients with low LDL-C and elevated TG [1–2]. Its main limitation resides in the estimation of cholesterol in the VLDL particle. Applying a fixed denominator of 2.2 to the parameter TG/2.2 (TG/5 in mg/dl) to estimate the amount of cholesterol in VLDL may lead to inaccuracies in the estimation of LDL- C. This ratio can vary substantially as the amount of TG changes [3]. Alternate lipid targets have been proposed in order to circumvent this problem [4–5]. Martin et al. [6] in 2013 developed a novel method to calculate LDL-C using an adjustable factor based on TG and Non-HDL-C to esti- mate the amount of cholesterol in VLDL. Subsequent publications using Familial Combined Hyperlipidemia patients [7] and high risk patients including PCSK9 inhibitor treated patients [8] have confirmed its value particularly in patients with low LDL-C. Recent data [9] have also shown that this new approach improves the accuracy for estimating LDL-C in patients that are not fasting. The AHA/ACC 2018 Cholesterol Clinical Practice Guidelines [10], recommend that for patients with an LDL-C level less than 1.8 mmol/L (< 70 mg/dl), the modified LDL-C estimate as developed by Martin and Hopkins should preferably be used over the Friedewald formula. Here we report on the lipid profile data from 4150 high cardiac risk patients. Our purpose is to evaluate the Martin/Hopkins equation for estimating LDL-C in a population composed of high cardiac risk pa- tients. According to the Canadian guidelines, an LDL-C value below 1.8–2.0 mmol/L (70–77 mg/L) is a primary target for those high risk patients. Non-HDL-C < 2.6 mmol/L(100 mg/dl) and ApoB < 0.8 g/L will be used as comparators in terms of target attainment, as per the 2016 Canadian Lipid Guidelines [4]. https://doi.org/10.1016/j.clinbiochem.2019.12.002 Received 3 October 2019; Received in revised form 27 November 2019; Accepted 3 December 2019 ⁎ Corresponding author at: The Moncton Hospital, 135 MacBeath Ave, Moncton New Brunswick E1C6Z8, Canada. E-mail address: Dr.Louis.Cartier@horizonnb.ca (L.-J. Cartier). Clinical Biochemistry xxx (xxxx) xxx–xxx 0009-9120/ © 2019 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved. Please cite this article as: Louis-Jacques Cartier, et al., Clinical Biochemistry, https://doi.org/10.1016/j.clinbiochem.2019.12.002