The First Department of Internal Medicine, Gifu University School of Medicine, Gifu, Japan.
Hepatol Res. 2014 Feb;44(2):218-28. doi: 10.1111/hepr.12112. Epub 2013 Apr 18.
Protein-energy malnutrition is frequently observed in patients with liver cirrhosis (LC). Non-protein respiratory quotient (npRQ) measured by indirect calorimetry is a good marker to estimate energy malnutrition, and predicts the prognosis of patients with LC. However, measurement of npRQ is limited because of the high cost of indirect calorimetry. Our aim was to find out an alternative marker to npRQ that can be used in the routine clinical setting.
One hundred and fifty-six patients with LC were enrolled in this study. Indirect calorimetry and blood examinations were conducted after overnight fasting, and anthropometry was performed by an expert dietician. The correlation between npRQ and other parameters were calculated by simple and multiple regression analysis. Receiver-operator curve (ROC) analysis was used to identify the cut-off value that would best predict the threshold npRQ of 0.85.
Plasma levels of free fatty acid (FFA) was significantly correlated with npRQ value by simple (r = -0.39, P < 0.0001) and multiple regression analysis (t = -2.96, P = 0.0052). Free fatty acid rose in parallel with the increasing disease severity as defined by Child-Pugh classification (P < 0.05). FFA was also correlated with increasing oxidation rate of fat (r = 0.38, P < 0.0001) and decreasing oxidation rate of carbohydrate (r = -0.39, P < 0.0001). The cut-off value of FFA to predict npRQ = 0.85 was 660 μEq/L by ROC analysis.
FFA is a useful alternative marker to represent npRQ in patients with LC.
肝硬化（LC）患者常出现蛋白质-能量营养不良。间接测热法测量的非蛋白呼吸商（npRQ）是评估能量营养不良的良好标志物，并可预测 LC 患者的预后。然而，由于间接测热法费用较高，npRQ 的测量受到限制。我们的目的是寻找一种可替代 npRQ 的标志物，可用于常规临床环境。
本研究纳入 156 例 LC 患者。患者隔夜禁食后进行间接测热法和血液检查，并由专业营养师进行人体测量。通过简单和多元回归分析计算 npRQ 与其他参数之间的相关性。采用受试者工作特征曲线（ROC）分析确定最佳预测 npRQ 阈值 0.85 的截断值。
简单（r=-0.39，P<0.0001）和多元回归分析（t=-2.96，P=0.0052）显示，血浆游离脂肪酸（FFA）水平与 npRQ 值显著相关。FFA 随着 Child-Pugh 分级定义的疾病严重程度增加而平行升高（P<0.05）。FFA 还与脂肪氧化率增加（r=0.38，P<0.0001）和碳水化合物氧化率降低（r=-0.39，P<0.0001）相关。ROC 分析显示，FFA 预测 npRQ=0.85 的截断值为 660μEq/L。
FFA 是 LC 患者代表 npRQ 的有用替代标志物。
