Decsi T, Molnár D, Koletzko B
Department of Paediatrics, University Medical School of Pécs, Hungary.
Lipids. 1996 Mar;31(3):305-11. doi: 10.1007/BF02529877.
Fatty acid composition of plasma phospholipids (PL), triglycerides (TG), and sterol esters (STE) was determined by high-resolution capillary gas-liquid chromatography in 22 obese children (age: 13.7 +/- 1.4 y, body weight relative to normal weight for height: 170 +/- 24%, mean +/- SD) and compared with data obtained in 25 age-matched healthy controls. There were no differences in the levels of linoleic acid (LA, C18:2n-6) in any of the plasma fractions from obese children and the controls. Obese children exhibited significantly higher values of arachidonic acid (AA, C20:4n-6) than controls both in PL (12.6 [2.4] vs. 8.3 [1.4], % wt/wt, [median (interquartile range)], P < 0.001) and STE (7.3 [1.8] vs. 6.0 [1.1], P < 0.05). Similarly, obese children showed higher values than controls for dihomo-gamma-linoleic acid (DHGLA, C20:3n-6) in PL (4.0 [0.5] vs. 3.0 [0.6], P < 0.001), TG (0.4 [0.1] vs. 0.2 [0.1], P < 0.001), and STE (0.9 [0.1] vs. 0.7 [0.1], P < 0.01), and for gamma-linolenic acid (C18:3n-6) in STE (1.1 [0.2] vs. 0.8 [0.2], P < 0.001). The AA/LA ratios were higher in obese children than in controls in PL (0.68 [0.16] vs. 0.42 [0.09], P < 0.0005) and STE (0.16 [0.04] vs. 0.12 [0.02], P < 0.05), whereas the AA/DHGLA ratios were lower in TG of obese children than in controls (3.40 [0.64] vs. 5.10 [1.75], P < 0.005). Plasma glucose concentrations were inversely related to AA in TG (r = 0.53, P < 0.05), and plasma TG concentrations were inversely related to AA in PL and STE (r = -0.49, P < 0.05 and r = -0.48, P < 0.05) and to the AA/DHGLA ratios in PL (r = -0.57, P < 0.01), TG (r = -0.56, P < 0.01), and STE (r = -0.56, P < 0.01). We conclude that the significantly higher values of n-6 long-chain polyunsaturated fatty acids (LCP) in plasma lipids of obese children than in age-matched controls may be caused by an enhanced activity of delta 6-desaturation, and we speculate that elevated fasting immunoreactive insulin seen in obese children (19.4 +/- 8.0 microU/mL) may stimulate synthesis of n-6 LCP fatty acids.
采用高分辨率毛细管气液色谱法测定了22名肥胖儿童（年龄：13.7±1.4岁，身高体重相对于正常体重：170±24%，均值±标准差）血浆磷脂（PL）、甘油三酯（TG）和甾醇酯（STE）的脂肪酸组成，并与25名年龄匹配的健康对照者的数据进行了比较。肥胖儿童和对照者血浆各组分中亚油酸（LA，C18:2n-6）水平无差异。肥胖儿童PL中花生四烯酸（AA，C20:4n-6）值显著高于对照者（12.6 [2.4] 对 8.3 [1.4]，%重量/重量，[中位数（四分位间距）]，P < 0.001），STE中也是如此（7.3 [1.8] 对 6.0 [1.1]，P < 0.05）。同样，肥胖儿童PL中双高γ-亚麻酸（DHGLA，C20:3n-6）值高于对照者（4.0 [0.5] 对 3.0 [0.6]，P < 0.001），TG中（0.4 [0.1] 对 0.2 [0.1]，P < 0.001），STE中（0.9 [0.1] 对 0.7 [0.1]，P < 0.01），STE中γ-亚麻酸（C18:3n-6）值也高于对照者（1.1 [0.2] 对 0.8 [0.2]，P < 0.001）。肥胖儿童PL中（0.68 [0.16] 对 0.42 [0.09]，P < 0.0005）和STE中（0.16 [0.04] 对 0.12 [0.02]，P < 0.05）的AA/LA比值高于对照者，而肥胖儿童TG中的AA/DHGLA比值低于对照者（3.40 [0.64] 对 5.10 [1.75]，P < 0.005）。血浆葡萄糖浓度与TG中的AA呈负相关（r = 0.53，P < 0.05），血浆TG浓度与PL和STE中的AA呈负相关（r = -0.49，P < 0.05和r = -0.48，P < 0.05），与PL、TG和STE中的AA/DHGLA比值呈负相关（r = -0.57，P < 0.01，r = -0.56，P < 0.01，r = -0.56，P < 0.01）。我们得出结论，肥胖儿童血浆脂质中n-6长链多不饱和脂肪酸（LCP）值显著高于年龄匹配的对照者，可能是由于δ6-去饱和酶活性增强所致，并且我们推测肥胖儿童中空腹免疫反应性胰岛素升高（19.4±8.0微单位/毫升）可能刺激n-6 LCP脂肪酸的合成。
