Department of Gastroenterology, Tokyo Medical University, Japan.
Hepatol Res. 2009 Feb;39(2):149-56. doi: 10.1111/j.1872-034X.2008.00450.x.
The effect of dietary cholesterol on plasma cholesterol concentrations varies widely among individuals. Recent studies suggest that the synthesis of oxysterols is up-regulated when tissue cholesterol is saturated. The present study was undertaken to test the hypothesis that a serum high concentration of 27-hydroxycholesterol, one of the oxysterols, reflects positive cholesterol balance in the body and predicts intolerance to a high-cholesterol diet.
In 30 subjects, 750 mg/day of cholesterol was added for 4 weeks to the ordinary diet. Blood samples were collected at the start and finish of the supplementation. Serum sterol and oxysterol concentrations were measured by high-resolution GC-MS.
A receiver operating characteristic curve was drawn and the cutoff point (80 ng/mg cholesterol) was chosen to maximize sensitivity (81.3%) and specificity (64.3%) for predicting a positive change of LDL cholesterol concentration after cholesterol loading. Subjects with higher serum 27-hydroxycholesterol concentrations (>/= 80 ng/mg cholesterol) showed significantly (P < 0.05) high values for the change of LDL cholesterol concentration (+7.4 +/- 3.4%, mean +/- SEM, n = 17) compared with those with lower 27-hydroxycholesterol levels (-5.3 +/- 2.7%, n = 13).
In subjects with high serum 27-hydroxycholesterol concentrations were unable to adapt to a high-cholesterol diet. The concentration of serum 27-hydroxycholesterol appears to reflect cholesterol saturation in the body and predicts to some extent a responsiveness to dietary cholesterol.
膳食胆固醇对血浆胆固醇浓度的影响在个体之间差异很大。最近的研究表明，当组织胆固醇饱和时，氧化固醇的合成会上调。本研究旨在检验以下假设：血清中 27-羟胆固醇（一种氧化固醇）浓度高反映了体内胆固醇的正平衡，并预测对高胆固醇饮食的不耐受性。
在 30 名受试者中，在普通饮食中添加 750mg/天的胆固醇，持续 4 周。在补充开始和结束时采集血液样本。通过高分辨率 GC-MS 测量血清固醇和氧化固醇浓度。
绘制了受试者工作特征曲线，并选择了 80ng/mg 胆固醇的截断点，以最大限度地提高胆固醇负荷后 LDL 胆固醇浓度变化的敏感性（81.3%）和特异性（64.3%）。血清 27-羟胆固醇浓度较高（≥80ng/mg 胆固醇）的受试者与血清 27-羟胆固醇浓度较低的受试者（-5.3 ± 2.7%，n=13）相比，LDL 胆固醇浓度的变化明显更高（+7.4 ± 3.4%，均数 ± SEM，n=17）。
在血清 27-羟胆固醇浓度较高的受试者中，他们无法适应高胆固醇饮食。血清 27-羟胆固醇的浓度似乎反映了体内胆固醇的饱和程度，并在一定程度上预测了对膳食胆固醇的反应性。
