Division of Gastroenterology and Rheumatology, University Hospital Leipzig, Leipzig, Germany.
Clinical Trial Centre, University of Leipzig, Leipzig, Germany; IFB AdiposityDiseases, University of Leipzig, Leipzig, Germany.
J Hepatol. 2017 May;66(5):1022-1030. doi: 10.1016/j.jhep.2016.12.022. Epub 2016 Dec 28.
BACKGROUND & AIMS: The prevalence of fatty liver underscores the need for non-invasive characterization of steatosis, such as the ultrasound based controlled attenuation parameter (CAP). Despite good diagnostic accuracy, clinical use of CAP is limited due to uncertainty regarding optimal cut-offs and the influence of covariates. We therefore conducted an individual patient data meta-analysis.
A review of the literature identified studies containing histology verified CAP data (M probe, vibration controlled transient elastography with FibroScan®) for grading of steatosis (S0-S3). Receiver operating characteristic analysis after correcting for center effects was used as well as mixed models to test the impact of covariates on CAP. The primary outcome was establishing CAP cut-offs for distinguishing steatosis grades.
Data from 19/21 eligible papers were provided, comprising 3830/3968 (97%) of patients. Considering data overlap and exclusion criteria, 2735 patients were included in the final analysis (37% hepatitis B, 36% hepatitis C, 20% NAFLD/NASH, 7% other). Steatosis distribution was 51%/27%/16%/6% for S0/S1/S2/S3. CAP values in dB/m (95% CI) were influenced by several covariates with an estimated shift of 10 (4.5-17) for NAFLD/NASH patients, 10 (3.5-16) for diabetics and 4.4 (3.8-5.0) per BMI unit. Areas under the curves were 0.823 (0.809-0.837) and 0.865 (0.850-0.880) respectively. Optimal cut-offs were 248 (237-261) and 268 (257-284) for those above S0 and S1 respectively.
CAP provides a standardized non-invasive measure of hepatic steatosis. Prevalence, etiology, diabetes, and BMI deserve consideration when interpreting CAP. Longitudinal data are needed to demonstrate how CAP relates to clinical outcomes.
There is an increase in fatty liver for patients with chronic liver disease, linked to the epidemic of the obesity. Invasive liver biopsies are considered the best means of diagnosing fatty liver. The ultrasound based controlled attenuation parameter (CAP) can be used instead, but factors such as the underlying disease, BMI and diabetes must be taken into account. Registration: Prospero CRD42015027238.
脂肪肝的流行凸显了对肝脂肪变性进行非侵入性特征描述的必要性，例如基于超声的受控衰减参数（CAP）。尽管具有良好的诊断准确性，但由于不确定最佳截断值和协变量的影响，CAP 的临床应用受到限制。因此，我们进行了一项个体患者数据的荟萃分析。
对文献进行了回顾，确定了包含经组织学证实的 CAP 数据（M 探头，基于 FibroScan®的振动控制瞬态弹性成像）用于脂肪变性分级（S0-S3）的研究。使用校正中心效应后的受试者工作特征分析以及混合模型来测试协变量对 CAP 的影响。主要结局是确定区分脂肪变性分级的 CAP 截断值。
纳入了 19/21 篇符合条件的论文的数据，涵盖了 3830/3968（97%）例患者。考虑到数据重叠和排除标准，最终分析纳入了 2735 例患者（乙型肝炎 37%，丙型肝炎 36%，非酒精性脂肪性肝病/非酒精性脂肪性肝炎 20%，其他 7%）。脂肪变性的分布为 S0/S1/S2/S3 分别为 51%/27%/16%/6%。dB/m（95%CI）的 CAP 值受多种协变量影响，非酒精性脂肪性肝病/非酒精性脂肪性肝炎患者的 CAP 值估计偏移 10（4.5-17），糖尿病患者的 CAP 值偏移 10（3.5-16），BMI 每增加一个单位则偏移 4.4（3.8-5.0）。曲线下面积分别为 0.823（0.809-0.837）和 0.865（0.850-0.880）。对于 S0 和 S1 以上的患者，最佳截断值分别为 248（237-261）和 268（257-284）。
CAP 提供了一种标准化的肝脂肪变性的非侵入性测量方法。在解释 CAP 时，需要考虑患病率、病因、糖尿病和 BMI。需要进行纵向数据研究以证明 CAP 与临床结局的关系。
慢性肝病患者的脂肪肝患病率增加，与肥胖症的流行有关。肝活检被认为是诊断脂肪肝的最佳方法。基于超声的受控衰减参数（CAP）可替代，但必须考虑潜在疾病、BMI 和糖尿病等因素。注册：PROSPERO CRD42015027238。
