Clinical Chemistry Laboratory, Department of Laboratory Medicine, San Francisco General Hospital, University of California, San Francisco, CA, United States.
Clinical Chemistry Laboratory, Department of Laboratory Medicine, San Francisco General Hospital, University of California, San Francisco, CA, United States.
Clin Chim Acta. 2014 Mar 20;430:43-7. doi: 10.1016/j.cca.2013.12.040. Epub 2014 Jan 4.
The analysis of blood for β-sitosterol and campesterol is the measures of cholesterol absorption while lathosterol is a measure of cholesterol synthesis.
The biological variability of β-sitosterol, campesterol, and lathosterol was measured using liquid-chromatography tandem mass spectrometry from a cohort of 25 apparently healthy subjects, where blood was taken once every weeks for 6 weeks. The analytical, intra-individual, and group inter-individual variations (CVA, CV(I), and CV(G), respectively) were calculated.
Using absolute values, the CVI for β-sitosterol, campesterol, and lathosterol was 11.8%, 11.8%, and 22.5%, respectively, and the CV(G) was 28.5%, 28.8%, and 52.0%, respectively. This produced reference change values of about 24-36% for declining values and 32-47% for increasing values. The index of individuality was between 0.41 and 0.58, indicating that population based reference values are of little use for these biomarkers. The number of points needed for a homeostatic setpoint was 5 samples for β-sitosterol and campesterol, and 19 samples for lathosterol. Similar findings were observed for values when normalized to total cholesterol. These results were higher than the biological variation for total, low density and high density cholesterol obtained from the literature. Results were essentially identical when sterol values were corrected to their respective total cholesterol concentration.
The establishment of the biological variation for these biomarkers enables their use in the interpretation of results from clinical trials and lipid lowering treatment of patients at risk for cardiovascular disease in clinical practice.
β-谷甾醇和菜油甾醇的血液分析是胆固醇吸收的衡量标准，而羊毛甾醇是胆固醇合成的衡量标准。
通过液相色谱串联质谱法，从 25 名健康受试者中测量了β-谷甾醇、菜油甾醇和羊毛甾醇的生物学变异性，其中血液每 6 周采集一次，共采集 6 周。计算了分析、个体内和组间个体变异（CVA、CV（I）和 CV（G））。
使用绝对值，β-谷甾醇、菜油甾醇和羊毛甾醇的 CV（I）分别为 11.8%、11.8%和 22.5%，CV（G）分别为 28.5%、28.8%和 52.0%。这产生了大约 24-36%的下降值和 32-47%的上升值的参考变化值。个体指数在 0.41 到 0.58 之间，表明基于人群的参考值对于这些生物标志物几乎没有用处。β-谷甾醇和菜油甾醇的内稳态设定点需要 5 个样本，羊毛甾醇需要 19 个样本。当标准化为总胆固醇时，也观察到了类似的数值发现。这些结果高于从文献中获得的总胆固醇、低密度和高密度胆固醇的生物学变异。当固醇值校正到各自的总胆固醇浓度时，结果基本相同。
这些生物标志物的生物学变异的建立使其能够用于解释临床试验结果和心血管疾病高危患者的降脂治疗。
