Analysis of low-density lipoprotein in diabetic patients using the Martin/Hopkins and Sampson equations

Metabolic diseases; Dyslipidemia; Coronary artery disease; Diabetes Mellitus; Lipoprotein LDL

Dear Editor,

We read with great interest the article: Comparison of Novel Martin/Hopkins and Sampson Equations for Calculation of Low-Density Lipoprotein Cholesterol in Diabetic Patients. The study compared the Martin/Hopkins (LDL-Cmh), Sampson (LDL-Cs), and Friedewald (LDL-Cf) equations with directly obtained low-density lipoprotein (LDL-Cd). The aim was to analyze which would have a greater agreement with LDL-Cd in diabetic patients and investigate how these new equations could change clinical decision-making compared to LDL-Cf.¹

It is already established in the literature that low-density lipoprotein (LDL-c) is strongly associated with cardiovascular diseases (CVD), and patients with diabetes mellitus (DM) are at increased risk due to the atherogenic capacity that LDL-c promotes, mainly to chronic endothelial damage developed by the hyperinflammatory state of persistent hyperglycemia.² Therefore, accurate measurement of LDL-c is essential for the clinical follow-up of these patients.

In the article, the use of LDL-Cmh and LDL-Cs showed a strong correlation with LDL-Cd, not requiring the reclassification of individuals. Both equations were better than LDL-Cf, especially triglyceride (TG) levels > 150 mg/dl. LDL-Cmh had an almost excellent agreement with LDL-Cd in individuals who had TG values between 150-400 mg/dl, requiring only 1.5% of patients to be reclassified when using LDL-Cmh. However, all equations behaved badly when the TG concentration was > 400 mg/dl, allowing only less than 90% of the individuals to be classified correctly. Furthermore, the concordance between LDL-Cd and calculated LDL-c was poor when the LDL-c value was < 70 mg/dl.¹

The article’s authors state that the equations for LDL-Cmh and LDL-Cs showed similar concordance for LDL-Cd. Thus, clinical decision-making should be similar in most patients, regardless of which equation is used. For those individuals with a TG of 150 to 400 mg/dl, LDL-Cmh presented an almost perfect agreement with LDL-Cd, concerning being within the LDL-C target, making it preferable for patients with DM in this range of TG.¹

However, it was noticed that in the process of obtaining the population sample, even in diabetic patients, the statistical analysis considered only the TG variable on the behavior of agreement, underestimation, and overestimation in the analyzed equations. Therefore, since DM is a chronic, multifactorial process with different clinical presentations and therapeutic approaches, there may have been confounding factors in analyzing the behavior of the equations in diabetic individuals, because the patients were not stratified according to the type of DM, class of antidiabetics used, non-medication and medication adherence, anthropometric parameters, and liver function.

Referências

• ¹
  Naser A, Isgandarov K, Güvenç TS, Güvenç R, Sahin M. Comparison of Novel Martin/Hopkins and Sampson Equations for Calculation of Low-Density Lipoprotein Cholesterol in Diabetic Patients. Arq Bras Cardiol.2022;119(2):225. Doi:10.36660/abc20210641
• ²
  Faludi AA, Izar MCO, Saraiva JFK, Chacra APM, Bianco HT, Afine Neto A et al. Atualização da Diretriz Brasileira de Dislipidemias e Prevenção da Aterosclerose - 2017. Arq Bras Cardiol 2017; 109(2Supl.1):1-76. Doi: 10.5935/abc.20170121
• ¹
  Naser A, Isgandarov K, Güvenç TS, Güvenç RÇ, Şahin M. Comparison of Novel Martin/Hopkins and Sampson Equations for Calculation of Low-Density Lipoprotein Cholesterol in Diabetic Patients. Arq Bras Cardiol. 2022 Aug;119(2):225-233. English, Portuguese. doi: 10.36660/abc.20210641. PMID: 35766617; PMCID: PMC9363054.
• ²
  Nascimento CR, Mendes R, Botelho Filho CAL, Barbosa RHA, Tenório PP. Análise da Lipoproteína de Baixa Densidade em Pacientes Diabéticos a Partir das Equações de Martin/Hopkins e Sampson. DOI: https://doi.org/10.36660/abc.20220859
  » https://doi.org/10.36660/abc.20220859
• ³
  Friedewald WT, Levy RI, Fredrickson DS. Estimation of the concentration of low-density lipoprotein cholesterol in plasma, without use of the preparative ultracentrifuge. Clin Chem 1972 Jun;18(6):499-502.
• ⁴
  Sampson M, Ling C, Sun Q, Harb R, Ashmaig M, Warnick R, et al. A new equation for calculation of low-density lipoprotein cholesterol in patients with normolipidemia and/or hypertriglyceridemia. JAMA Cardiol. 2020 May 1; 5:540-548. doi: 10.1001/jamacardio.2020.0013.
• ⁵
  Martin SS, Blaha MJ, Elshazly MB, Toth PP, Kwiterovich PO, Blumenthal RS, et al. Comparison of a novel method vs the Friedewald equation for estimating low-density lipoprotein cholesterol levels from the standard lipid profile. JAMA 2013 Nov 20; 310:2061-8. doi: 10.1001/jama.2013.280532.

Publication Dates

• Publication in this collection
  26 May 2023
• Date of issue
  2023