Concordance of apolipoprotein B concentration with the Friedewald,Martin-Hopkins,and Sampson formulas for calculating LDL cholesterol

IntroductionTwo new formulas, the Martin-Hopkins and the Sampson formula, were recently developed to overcome shortcomings of the Friedewald formula for calculating LDL-cholesterol. We aimed to compare the concordance of the two formulas with apolipoprotein B (apoB), a surrogate marker of the number of LDL particles.Materials and methodsIn a study of serum lipid data of 1179 patients who consulted the AZ St-Jan Hospital Bruges for cardiovascular risk assessment, the correlation and concordance of the Friedewald, Martin-Hopkins and Sampson formulas with apoB concentration, measured by immunonephelometry, were determined and compared.ResultsThe Martin-Hopkins formula showed significantly higher correlation coefficient than the Friedewald formula with apoB in the entire dataset and in patients with low LDL-cholesterol < 1.8 mmol/L. Both Martin-Hopkins and Sampson formulas yielded > 70% concordance of LDL-cholesterol with regard to treatment group classification based on population-equivalent thresholds of apoB in hypertriglyceridemic patients (2-4.5 mmol/L), with the highest concordance (75.6%) obtained using Martin-Hopkins formula vs. 60.5% with Friedewald formula.ConclusionThe Martin-Hopkins (and, to a lesser extent, Sampson) formula is more closely associated with the number of LDL particles than Friedewald formula. This, in combination with literature evidence of lesser accuracy of the Friedewald formula, is an argument to switch from Friedewald to a modified, improved formula.     

Effect of supplementation of vitamin E, vitamin C and reduced glutathione on copper ion induced lipoprotein oxidation in renal diseased patients—Anin vitro study

The oxidative modification of lipoprotein especially low density lipoprotein (LDL) plays a key role in the initiation and progression of atherosclerosis. Serum apolipoproteinB (apoB) level is found to be an important marker for atherosclerosis. The present paper focuses on the measurement of serum apoB levels and the effect of Vitamin E, Vitamin C and reduced glutathione on the copper ion induced oxidation of LDL + VLDL (VLDL-Very Low Density Lipoprotein) lipoprotein fraction isolated from the serum of chronic renal failure (CRF) and renal transplanted patients. The level of apoB is significantly higher in the serum of transplanted patients when compared to CRF patients and normal subjects. The level of TBARS formed in oxidized LDL + VLDL lipoprotein fraction of CRF and renal transplanted patients are significantly increased than normal even in the presence of antioxidants but the level of TBARS produced, with antioxidants is comparatively lesser than that produced by oxidized lipoprotein fraction without antioxidants. It may be concluded than that produced by oxidized lipoprotein fraction without antioxidants. It may be concluded that oxidation of LDL can be prevented at an earlier stage by Vitamin E supplementation. The supplementation with Glutathione serves as the best method of preventing the lipoprotein oxidation among the renal diseased patients.     

Preliminary studies on serum lipids, apolipoprotein-B and oxidative stress in xanthelasma

Serum lipid profile, apolipoprotein-B (apo-B), malondialdehyde levels(MDA) and superoxide dismutase (SOD) activity were assessed in 12 cases of xanthelasma with and without coronary artery disease (CAD)/hypertension (HTN) and results are compared with healthy controls. Dyslipidemia was found in 65% cases of xanthelasma as compared to 20% healthy controls. Xanthelasma patients had significantly high malondialdehyde (MDA) levels (p<0.01) and significantly decreased (p<0.05) SOD activity as compared to controls. Among xanthelasma patients, xanthelasma with CAD/HTN showed higher total cholesterol (236±32.7 vs 188±24.7 mg/dl), low density lipoprotein cholesterol (157±35.5 vs 113±16 mg/dl) and Apo-B (120.5±9.4 vs 114±19.2 mg/dl) levels as compared to xanthelasma without CAD/HTN. Results of our study indicate that xanthelasma patients with increased apo-B, MDA and decreased SOD need cardiovascular monitoring.     

太极拳锻炼对中老年人血清脂蛋白组份及载脂蛋白水平的影响

对92例老年太极拳运动爱好者和86例不运动老年人的脂蛋白组份、载脂蛋白水平及比值进行了研究。结果显示:长期参加太极拳运动的老年人TC、TG、LDL-Ch与不参加运动的老年人相比无显著性差异,而HDL-Ch及分型、APOA-I、HDL-Ch/TC、HDL-Ch/LDL-Ch、APOA-I/APOB-100、APOB-100/LDL显著高于不运动的老年人。血脂、脂蛋白、载脂蛋白与锻炼时间呈显著相关性,而与年龄、身高无显著相关。     

有氧运动改善饮食性高脂血症分子机理的研究Ⅰ——有氧游泳运动对高脂血症大鼠血清脂质、脂蛋白和载脂蛋白水平的影响

运动预防高脂血症的发生和发展是临床医学和运动医学领域内的重要课题之一。在以往研究工作基础上 ,从建立高脂高胆固醇膳食诱导 SD大鼠高脂血症的实验动物模型和有氧运动训练的模型入手 ,观察高脂、高胆固醇膳食对大鼠血清脂质、脂蛋白和载脂蛋白水平的影响以及有氧游泳运动对其的预防和改善作用。结果表明 :有氧游泳运动可在一定程度上对抗和缓解高脂高胆固醇膳食对血清脂质、脂蛋白的不利影响。其分子机理 ,如运动对载脂蛋白、脂代谢关键酶和受体基因表达影响的研究正在进行中     

ApoE基因多态性和运动与脂质代谢及冠心病的研究进展

ApE在血浆脂质代谢中有重要作用，三种主要异构体E2、E3、FA，有三个常见的等位基因编码。与ε3等位基因相比，ε2等位基因与较低的血浆TC、LDL—c。ε4等位基因与较高的血浆TC、LDL—c相关。ε4等位基因是冠心病的遗传易患因子，而ε2是冠心病的遗传保护因子，但目前又出现了一些争议。纵向和横向的研究普遍显示：长期耐力训练后，ApoE2、ApoE3人群血脂的改善大于ApoFA人群。上述结论提示我们在不久的将来。依据ApE基因型制定个体改善血浆脂蛋白和冠心病风险的特异性运动处方将成为可能。