Post-Graduation Program in Pharmacy, Department of Clinical Analyses, Health Sciences Center, Federal University of Santa Catarina, Florianópolis, SC, Brazil.
Clin Chem Lab Med. 2012 Mar 3;50(9):1649-56. doi: 10.1515/cclm-2011-0797.
In the study reported herein, we used the precipitation method employing heparin-Mg(2+), with slight modifications to avoid lipemia interference, to measure small dense-low density lipoprotein-cholesterol (sd-LDL-C) in Brazilian subjects with a high risk of developing cardiovascular diseases.
Lipemic samples were diluted with various solvents prior to precipitation with heparin-Mg(2+). Validation assays were performed with ultracentrifugation (n=100) and the reproducibility of sd-LDL-C measured in diluted serum (n=50). The applicability of this modification was evaluated by measuring sd-LDL-C in 434 southern Brazilian normolipidemic, dyslipidemic and type 2 diabetes mellitus (T2DM) individuals.
Lipemic serum diluted with 100 mmol/L phosphate buffer pH 8.5 was effective for the quantification of sd-LDL-C, which was correlated with non-diluted serum (r=0.961; p<0.0001) and with ultracentrifugation (r=0.705; p<0.0001). Ultracentrifugation sd-LDL-C was 0.08 mmol/L (CI 95%: -0.42-0.58 mmol/L) higher than the precipitation method (p>0.05). Subjects with dyslipidemias and T2DM had, respectively, 2.3 and 2.6-fold higher sd-LDL-C concentrations than normolipidemic individuals (p<0.05). The incidence of normolipidemic subjects with a high concentration of sd-LDL-C was only 2.2%. The sd-LDL-C was found to be enhanced by 8.3% every 10 years and young normolipidemic men had 24% higher sd-LDL-C than young women (p<0.05). Lipid-lowering therapy reduced sd-LDL-C by 26% (p<0.001).
In this paper we described a simple and inexpensive approach to improving the measurement of sd-LDL-C in high-triglycerides serum. Furthermore, we showed that southern Brazil dyslipidemic and T2DM individuals have increased sd-LDL-C concentrations.
在本研究中，我们使用肝素-Mg(2+)沉淀法，稍加修改以避免脂血干扰，来测量巴西心血管疾病高危人群的小而密低密度脂蛋白胆固醇(sd-LDL-C)。
用各种溶剂稀释脂血样本，然后用肝素-Mg(2+)沉淀。用超速离心法(n=100)和稀释血清中 sd-LDL-C 的重复性(n=50)进行验证试验。通过测量 434 名南里奥格兰德州正常血脂、血脂异常和 2 型糖尿病(T2DM)个体的 sd-LDL-C，评估该改良方法的适用性。
用 100mmol/L 磷酸盐缓冲液 pH 8.5 稀释的脂血血清可有效定量 sd-LDL-C，与未稀释血清(r=0.961；p<0.0001)和超速离心(r=0.705；p<0.0001)相关。超速离心法测定的 sd-LDL-C 比沉淀法高 0.08mmol/L(95%CI：-0.42-0.58mmol/L)(p>0.05)。血脂异常和 T2DM 患者的 sd-LDL-C 浓度分别比正常血脂个体高 2.3 倍和 2.6 倍(p<0.05)。正常血脂个体中 sd-LDL-C 浓度高的发生率仅为 2.2%。sd-LDL-C 每增加 10 年增加 8.3%，年轻正常血脂男性的 sd-LDL-C 比年轻女性高 24%(p<0.05)。降脂治疗可使 sd-LDL-C 降低 26%(p<0.001)。
本文描述了一种简单、经济的方法，可改善高甘油三酯血清中 sd-LDL-C 的测量。此外，我们还发现南里奥格兰德州血脂异常和 T2DM 个体的 sd-LDL-C 浓度升高。
