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Martins J, Steyn N, Rossouw HM, Pillay TS. Best practice for LDL-cholesterol: when and how to calculate. J Clin Pathol 2023; 76:145-152. [PMID: 36650044 DOI: 10.1136/jcp-2022-208480] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 11/23/2022] [Indexed: 01/19/2023]
Abstract
The lipid profile is important in the risk assessment for cardiovascular disease. The lipid profile includes total cholesterol, high-density lipoprotein (HDL)-cholesterol, triglycerides (TGs) and low-density lipoprotein (LDL)-cholesterol (LDL-C). LDL-C has traditionally been calculated using the Friedewald equation (invalid with TGs greater than 4.5 mmol/L and is based on the assumption that the ratio of TG to cholesterol in very- low-density lipoprotein (VLDL) is 5 when measured in mg /dL). LDL-C can be quantified with a reference method, beta-quantification involving ultracentrifugation and this is unsuitable for routine use. Direct measurement of LDL-C was expected to provide a solution with high TGs. However, this has some challenges because of a lack of standardisation between the reagents and assays from different manufacturers as well as the additional costs. Furthermore, mild hypertriglyceridaemia also distorts direct LDL-C measurements. With the limitations of the Friedewald equation, alternatives have been derived. Newer equations include the Sampson-National Institutes of Health (NIH) equation 2 and the Martin-Hopkins equation. The Sampson-NIH2 equation was derived using beta-quantification in a population with high TG and multiple least squares regression to calculate VLDL-C, using TGs and non-HDL-C as independent variables. These data were used in a second equation to calculate LDL-C. The Sampson-NIH2 equation can be used with TGs up to 9 mmol/L. The Martin-Hopkins equation uses a 180 cell stratification of TG/non-HDL-C to determine the TG:VLDL-C ratio and can be used with TGs up to 4.5 mmol/L. Recently, an extended Martin-Hopkins equation has become available for TGs up to 9.04 mmol/L.This article discusses the best practice approach to calculating LDL-C based on the available evidence.
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Affiliation(s)
- Janine Martins
- Chemical Pathology, University of Pretoria, Pretoria, South Africa
| | - Nicolene Steyn
- Chemical Pathology, University of Pretoria, Pretoria, South Africa
| | - H Muller Rossouw
- Chemical Pathology, University of Pretoria, Pretoria, South Africa
| | - Tahir S Pillay
- Chemical Pathology, University of Pretoria, Pretoria, South Africa .,Chemical Pathology, University of Cape Town, Cape Town, South Africa
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2
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Lee S, Jeevaratnam K, Liu T, Chang D, Chang C, Wong WT, Wong ICK, Lip GYH, Tse G. Risk stratification of cardiac arrhythmias and sudden cardiac death in type 2 diabetes mellitus patients receiving insulin therapy: A population-based cohort study. Clin Cardiol 2021; 44:1602-1612. [PMID: 34545599 PMCID: PMC8571559 DOI: 10.1002/clc.23728] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 09/06/2021] [Accepted: 09/13/2021] [Indexed: 02/06/2023] Open
Abstract
INTRODUCTION Metabolic abnormalities may exacerbate the risk of adverse outcomes in patients with type 2 diabetes mellitus. The present study aims to assess the predictive value of HbA1c and lipid variability on the risks of sudden cardiac death (SCD) and incident atrial fibrillation (AF). METHODS The retrospective observational study consists of type 2 diabetic patients prescribed with insulin, who went to publicly funded clinics and hospitals in Hong Kong between January 1, 2009 and December 31, 2009. Variability in total cholesterol, low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C), triglyceride, and HbA1c were assessed through their SD and coefficient of variation. The primary outcomes were incident (1) ventricular tachycardia/ventricular fibrillation, actual or aborted SCD and (2) AF. RESULTS A total of 23 329 patients (mean ± SD age: 64 ± 14 years old; 51% male; mean HbA1c 8.6 ± 1.3%) were included. On multivariable analysis, HbA1c, total cholesterol, LDL-C and triglyceride variability were found to be predictors of SCD (p < .05). CONCLUSION HbA1c and lipid variability were predictive of SCD. Therefore, poor glucose control and variability in lipid parameters in diabetic patients are associated with aborted or actual SCD. These observations suggest the need to re-evaluate the extent of glycemic control required for outcome optimization.
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Affiliation(s)
- Sharen Lee
- Diabetes Research Unit, Cardiovascular Analytics Group, Hong Kong, China-UK Collaboration, China
| | | | - Tong Liu
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, China
| | - Dong Chang
- Xiamen Cardiovascular Hospital, Xiamen University, Xiamen, China
| | - Carlin Chang
- Division of Neurology, Department of Medicine, Queen Mary Hospital, Hong Kong, China
| | - Wing Tak Wong
- School of Life Sciences, Chinese University of Hong Kong, Hong Kong, China
| | - Ian Chi Kei Wong
- Department of Pharmacology and Pharmacy, University of Hong Kong, Pokfulam, China.,Medicines Optimisation Research and Education (CMORE), UCL School of Pharmacy, London, UK
| | - Gregory Y H Lip
- Liverpool Centre for Cardiovascular Science, University of Liverpool and Liverpool Heart & Chest Hospital, Liverpool, United Kingdom; and Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
| | - Gary Tse
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK.,Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, China.,Kent and Medway Medical School, Canterbury, Kent, UK
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Cordova CMMD, Galgowski C. Flexibilization of Fasting for Laboratory Determination of the Lipid Profile in Brazil: Science or Convenience? Arq Bras Cardiol 2019; 111:747-749. [PMID: 30484516 PMCID: PMC6248245 DOI: 10.5935/abc.20180174] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 04/11/2018] [Indexed: 12/05/2022] Open
Affiliation(s)
| | - Caroline Galgowski
- Fundação Universidade Regional de Blumenau (FURB), Blumenau, SC - Brazil
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Dong QT, Gao Y, Wu NQ, Guo YL, Zhu CG, Li S, Liu HH, Cao YX, Zhang HW, Zhao X, Liu G, Dong Q, Li JJ. Impact of glucose and lipid markers on the correlation of calculated and enzymatic measured low-density lipoprotein cholesterol in diabetic patients with coronary artery disease. J Clin Lab Anal 2018; 32:e22399. [PMID: 29380428 DOI: 10.1002/jcla.22399] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2017] [Accepted: 01/10/2018] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND AND AIMS Low-density lipoprotein cholesterol (LDL-C) is widely estimated by Friedewald equation (FE) and Enzymatic test (ET), which are affected by several factors. The aim of this study was to observe the impact of diabetic lipid and glucose patterns on the correlation between FE LDL-C (F-LDL) and ET LDL-C (E-LDL) in patients with coronary artery disease (CAD). METHODS AND RESULTS A total of 8155 CAD patients were consecutively enrolled and their lipid profiles were measured. The impacts of triglyceride (TG), glycosylated hemoglobin A1c (HbA1c), and high-density lipoprotein cholesterol (HDL-C) on the correlation of F-LDL and E-LDL were examined. The difference value (DV) between F-LDL and E-LDL was compared using ANOVA test. The CAD patients with DM were elder and had higher body mass index, plasma TG compared with those without DM (P < .05 separately). In the whole population, F-LDL was lower than E-LDL but showed a high correlation with E-LDL (r = .970, P = .000). Moreover, as the TG concentrations increased, the DV increased accordingly but the correlation between F-LDL and E-LDL decreased (P < .01). The similar trend was also found in both DM and non-DM patients comparing with different TG groups. However, in patients with DM, there was no significant difference of DV in different HbA1c groups or HDL-C concentrations (P > .05). CONCLUSION Although F-LDL might underestimate the value of LDL-C, the correlation between F-LDL and E-LDL was clinically acceptable (r = .97), suggesting the LDL-C values measured by two methods were similarly reliable in CAD patients with or without DM.
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Affiliation(s)
- Qiu-Ting Dong
- The Division of Dyslipidemia, State Key Laboratory of Coronary Artery Disease, National Centre for Coronary Artery Diseases, Chinese Academy of Medical Sciences, Peking Union Medical College, Fu Wai Hospital, Beijing, China
| | - Ying Gao
- The Division of Dyslipidemia, State Key Laboratory of Coronary Artery Disease, National Centre for Coronary Artery Diseases, Chinese Academy of Medical Sciences, Peking Union Medical College, Fu Wai Hospital, Beijing, China
| | - Na-Qiong Wu
- The Division of Dyslipidemia, State Key Laboratory of Coronary Artery Disease, National Centre for Coronary Artery Diseases, Chinese Academy of Medical Sciences, Peking Union Medical College, Fu Wai Hospital, Beijing, China
| | - Yuan-Lin Guo
- The Division of Dyslipidemia, State Key Laboratory of Coronary Artery Disease, National Centre for Coronary Artery Diseases, Chinese Academy of Medical Sciences, Peking Union Medical College, Fu Wai Hospital, Beijing, China
| | - Cheng-Gang Zhu
- The Division of Dyslipidemia, State Key Laboratory of Coronary Artery Disease, National Centre for Coronary Artery Diseases, Chinese Academy of Medical Sciences, Peking Union Medical College, Fu Wai Hospital, Beijing, China
| | - Sha Li
- The Division of Dyslipidemia, State Key Laboratory of Coronary Artery Disease, National Centre for Coronary Artery Diseases, Chinese Academy of Medical Sciences, Peking Union Medical College, Fu Wai Hospital, Beijing, China
| | - Hui-Hui Liu
- The Division of Dyslipidemia, State Key Laboratory of Coronary Artery Disease, National Centre for Coronary Artery Diseases, Chinese Academy of Medical Sciences, Peking Union Medical College, Fu Wai Hospital, Beijing, China
| | - Ye-Xuan Cao
- The Division of Dyslipidemia, State Key Laboratory of Coronary Artery Disease, National Centre for Coronary Artery Diseases, Chinese Academy of Medical Sciences, Peking Union Medical College, Fu Wai Hospital, Beijing, China
| | - Hui-Wen Zhang
- The Division of Dyslipidemia, State Key Laboratory of Coronary Artery Disease, National Centre for Coronary Artery Diseases, Chinese Academy of Medical Sciences, Peking Union Medical College, Fu Wai Hospital, Beijing, China
| | - Xi Zhao
- The Division of Dyslipidemia, State Key Laboratory of Coronary Artery Disease, National Centre for Coronary Artery Diseases, Chinese Academy of Medical Sciences, Peking Union Medical College, Fu Wai Hospital, Beijing, China
| | - Geng Liu
- The Division of Dyslipidemia, State Key Laboratory of Coronary Artery Disease, National Centre for Coronary Artery Diseases, Chinese Academy of Medical Sciences, Peking Union Medical College, Fu Wai Hospital, Beijing, China
| | - Qian Dong
- The Division of Dyslipidemia, State Key Laboratory of Coronary Artery Disease, National Centre for Coronary Artery Diseases, Chinese Academy of Medical Sciences, Peking Union Medical College, Fu Wai Hospital, Beijing, China
| | - Jian-Jun Li
- The Division of Dyslipidemia, State Key Laboratory of Coronary Artery Disease, National Centre for Coronary Artery Diseases, Chinese Academy of Medical Sciences, Peking Union Medical College, Fu Wai Hospital, Beijing, China
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Mendes de Cordova CM, de Santa Helena ET, Galgowski C, Figueira VH, Setter GB, Markus MRP, Schmidt CO, Völzke H, Ittermann T. Evaluation of a new equation for LDL-c estimation and prediction of death by cardiovascular related events in a German population-based study cohort. Scand J Clin Lab Invest 2018. [PMID: 29517392 DOI: 10.1080/00365513.2018.1432070] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
A simple equation established by Cordova & Cordova (LDL-COR) was developed to provide an improved estimation of LDL-cholesterol in a large Brazilian laboratory database. We evaluated this new equation in a general population cohort in Pomerania, north-eastern Germany (SHIP Study) compared to other existing formulas (Anandaraja, Teerakanchana, Chen, Hattori, Martin, Friedewald and Ahmadi), and its power in the prediction of death by atherosclerosis related events as the primary outcome. Analysis was conducted on a cohort of 4075 individuals considering age, gender, use of lipid lowering therapy and associated co-morbidities such as diabetes, hepatic, kidney and thyroid disease. LDL-COR values had a lower standard deviation compared to the previously published equations: 0.92 versus 1.02, 1.02, 1.03, 1.04, 1.09, 1.10 and 1.74 mmol/L, respectively. All of the factors known to affect the results obtained by the Friedewald's equation (LDL-FW), except fibrate use, were associated with the difference between LDL-COR and LDL-FW (p < .01), with TSH being borderline (p = .06). LDL-COR determined a higher hazard ratio (1.23 versus 1.12, 1.19, 1.21, 1.19, 1.21 and 1.19) for cardiovascular disease related mortality, incident stroke or myocardial infarction compared to the other evaluated formulas, except for Ahmadi's (1.24), and the same adjusted predictive power considering all confounding factors. The proposed simple equation was demonstrated to be suitable for a more precise LDL-c estimation in the studied population. Since LDL-c is a parameter frequently requested by medical laboratories in clinical routine, and will probably remain so, precise methods for its estimation are needed when direct measurement is not available.
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Affiliation(s)
| | | | - Caroline Galgowski
- c Graduation Program in Chemistry , University of Blumenau , Blumenau , SC , Brazil
| | | | | | | | | | - Henry Völzke
- e Institute for Community Medicine , University of Greifswald , Greifswald , Germany
| | - Till Ittermann
- e Institute for Community Medicine , University of Greifswald , Greifswald , Germany
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Visit-to-visit lipid variability: Clinical significance, effects of lipid-lowering treatment, and (pharmaco) genetics. J Clin Lipidol 2018; 12:266-276.e3. [DOI: 10.1016/j.jacl.2018.01.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 12/30/2017] [Accepted: 01/03/2018] [Indexed: 12/24/2022]
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Klop B, Hartong SCC, Vermeer HJ, Schoofs MWCJ, Kofflard MJM. Risk of misclassification with a non-fasting lipid profile in secondary cardiovascular prevention. Clin Chim Acta 2017; 472:90-95. [PMID: 28689857 DOI: 10.1016/j.cca.2017.07.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2017] [Revised: 07/02/2017] [Accepted: 07/05/2017] [Indexed: 10/19/2022]
Abstract
AIMS Routinely fasting is not necessary for measuring the lipid profile according to the latest European consensus. However, LDL-C tends to be lower in the non-fasting state with risk of misclassification. The extent of misclassification in secondary cardiovascular prevention with a non-fasting lipid profile was investigated. METHODS AND RESULTS 329 patients on lipid lowering therapy for secondary cardiovascular prevention measured a fasting and non-fasting lipid profile. Cut-off values for LDL-C, non-HDL-C and apolipoprotein B were set at <1.8mmol/l, <2.6mmol/l and <0.8g/l, respectively. Study outcomes were net misclassification with non-fasting LDL-C (calculated using the Friedewald formula), direct LDL-C, non-HDL-C and apolipoprotein B. Net misclassification <10% was considered clinically irrelevant. Mean age was 68.3±8.5years and the majority were men (79%). Non-fasting measurements resulted in lower LDL-C (-0.2±0.4mmol/l, P<0.001), direct LDL-C (-0.1±0.2mmol/l, P=0.001), non-HDL-C (-0.1±0.4mmol/l, P=0.004) and apolipoprotein B (-0.02±0.10g/l, P=0.004). 36.0% of the patients reached a fasting LDL-C target of <1.8mmol/l with a significant net misclassification of 10.7% (95% CI 6.4-15.0%) in the non-fasting state. In the non-fasting state net misclassification with direct LDL-C was 5.7% (95% CI 2.1-9.2%), 4.0% (95% CI 1.0-7.4%) with non-HDL-C and 4.1% (95% CI 1.1-9.1%) with apolipoprotein B. CONCLUSION Use of non-fasting LDL-C as treatment target in secondary cardiovascular prevention resulted in significant misclassification with subsequent risk of undertreatment, whereas non-fasting direct LDL-C, non-HDL-C and apolipoprotein B are reliable parameters.
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Affiliation(s)
- Boudewijn Klop
- Department of Cardiology, Albert Schweitzer Hospital, Dordrecht, The Netherlands.
| | - Simone C C Hartong
- Department of Internal Medicine, Albert Schweitzer Hospital, Dordrecht, The Netherlands
| | - Henricus J Vermeer
- Result Laboratorium, Dordrecht, The Netherlands; Department of Clinical Chemistry, Albert Schweitzer Hospital, Dordrecht, The Netherlands
| | | | - Marcel J M Kofflard
- Department of Cardiology, Albert Schweitzer Hospital, Dordrecht, The Netherlands
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