Malve Harshad, Asalkar Amit
Department of Pharmacology, Vedanta Institute of Medical Sciences, Sasvand, Dhundalwadi, Dahanu, Maharashtra, India.
Hormo-Care and Consultant Endocrinologist, Aster Aadhar Hospital, Kolhapur, Maharashtra, India.
J Lab Physicians. 2021 Jun;13(2):129-133. doi: 10.1055/s-0041-1729131. Epub 2021 May 26.
LDL cholesterol is routinely estimated by the Friedewald formula to guide the treatment of dyslipidemia. However, Friedewald equation has certain limitations, especially with high triglyceride levels. Direct methods are available for LDL estimation but have received relatively little scrutiny in the Indian setting. This study was aimed at comparing the calculative and direct methods of LDL estimation in Indian hyperlipidemic patients. In this observational study, data from 380 consecutive lipid profiles of patients visiting a tertiary care hospital in Mumbai were analyzed retrospectively. CHOD PAP method was used to estimate total cholesterol. Enzymatic colorimetric method was used to estimate triglycerides. Enzyme selective protection method was used to estimate HDL. Direct LDL was estimated by homogenous enzymatic colorimetric assay and very low-density lipoprotein was calculated, whereas Friedewald's formula was used to derive calculated LDL. Total cholesterol values correlated positively with the LDL values measured by both methods. However, a statistically significant difference was noted between the correlation coefficients of both the methods. Triglyceride values correlated weakly with the LDL levels measured by both the methods. A weak negative correlation was observed with LDL by the calculated method, whereas a weak positive correlation existed between TG and LDL by the direct method. The difference between the correlation coefficients was statistically significant. Both direct and calculated methods of LDL estimation have their limitations. A robust study with a larger sample size is needed to further investigate whether the differences in the different LDL estimation methods can translate to "clinical relevance" in the Indian setting.
低密度脂蛋白胆固醇通常通过弗里德瓦尔德公式进行估算，以指导血脂异常的治疗。然而，弗里德瓦尔德方程有一定的局限性，尤其是在高甘油三酯水平时。直接法可用于估算低密度脂蛋白，但在印度环境中受到的审查相对较少。本研究旨在比较印度高脂血症患者中低密度脂蛋白估算的计算法和直接法。
在这项观察性研究中，回顾性分析了孟买一家三级护理医院连续380例患者的血脂谱数据。采用CHOD PAP法估算总胆固醇。采用酶比色法估算甘油三酯。采用酶选择性保护法估算高密度脂蛋白。通过匀相酶比色法估算直接低密度脂蛋白，并计算极低密度脂蛋白，而弗里德瓦尔德公式用于推导计算所得的低密度脂蛋白。
总胆固醇值与两种方法测得的低密度脂蛋白值呈正相关。然而，两种方法的相关系数之间存在统计学显著差异。甘油三酯值与两种方法测得的低密度脂蛋白水平相关性较弱。通过计算法观察到与低密度脂蛋白呈弱负相关，而通过直接法观察到甘油三酯与低密度脂蛋白之间存在弱正相关。相关系数之间的差异具有统计学显著性。
低密度脂蛋白估算的直接法和计算法都有其局限性。需要进行一项样本量更大的有力研究，以进一步调查不同低密度脂蛋白估算方法的差异在印度环境中是否能转化为“临床相关性”。
