VanderJagt Dorothy J, Trujillo Miguel R, Bode-Thomas Fidelia, Huang Yung-Sheng, Chuang Lu-Te, Glew Robert H
Department of Biochemistry and Molecular Biology, University of New Mexico, School of Medicine, Albuquerque, NM, USA.
Lipids Health Dis. 2003 May 6;2:2. doi: 10.1186/1476-511x-2-2.
To determine the cholesterol content and fatty acid composition of red cell membrane phospholipids (PL) of children with sickle cell disease (SCD) and to correlate these levels with whole body phase angle that is related to the integrity and function of cell membranes.
Blood samples were obtained from 69 children with SCD and 72 healthy age- and gender-matched controls in Nigeria for the determination of the cholesterol content and proportions of fatty acids in red cell PL. Bioelectrical impedance analysis was used to obtain resistance (R) and reactance (Xc) from which phase angle was calculated as arctan Xc/R. Cholesterol (normalized to lipid phosphorus) and the proportions of individual fatty acids were correlated with phase angle.
The proportions of palmitic (p < 0.001), stearic acid (p = 0.003) and cholesterol (p < 0.001) were significantly higher in the red cells of children with SCD, whereas the proportions of arachidonic acid and docosahexaenoic acid were reduced (p = 0.03 and < 0.001, respectively) compared to controls. The phase angle was inversely correlated with the proportions of palmitic acid (p = 0.03) and oleic acid (p < 0.001) and cholesterol (p = 0.003). Three n-3 polyunsaturated fatty acids-eicosapentaenoic acid, docosapentaenoic acid and docosahexaenoic acid- were positively correlated with phase angle (p < 0.001).
The fatty acid composition and cholesterol content of tissue membranes in SCD correlate with the phase shift measured by bioelectrical impedance analysis. Phase angle measurements may provide a non-invasive method for monitoring interventions aimed at altering the lipid composition of membranes.
测定镰状细胞病（SCD）患儿红细胞膜磷脂（PL）的胆固醇含量和脂肪酸组成，并将这些水平与与细胞膜完整性和功能相关的全身相角进行关联。
从尼日利亚69例SCD患儿和72例年龄及性别匹配的健康对照者中采集血样，以测定红细胞PL中的胆固醇含量和脂肪酸比例。采用生物电阻抗分析法获取电阻（R）和电抗（Xc），并据此计算相角，计算公式为arctan Xc/R。将胆固醇（标准化为脂质磷）和各脂肪酸比例与相角进行关联分析。
与对照组相比，SCD患儿红细胞中棕榈酸（p < 0.001）、硬脂酸（p = 0.003）和胆固醇（p < 0.001）的比例显著升高，而花生四烯酸和二十二碳六烯酸的比例降低（分别为p = 0.03和p < 0.001）。相角与棕榈酸（p = 0.03）、油酸（p < 0.001）和胆固醇（p = 0.003）的比例呈负相关。三种n-3多不饱和脂肪酸——二十碳五烯酸、二十二碳五烯酸和二十二碳六烯酸——与相角呈正相关（p < 0.001）。
SCD组织膜的脂肪酸组成和胆固醇含量与生物电阻抗分析测得的相移相关。相角测量可能为监测旨在改变膜脂质组成的干预措施提供一种非侵入性方法。
