摘要目的:评估超声衰减参数（UAP）诊断代谢相关脂肪性肝病（MAFLD）肝脂肪变的效能，以此为基础建立诊断模型，探讨其评估MAFLD及相关代谢紊乱的价值。方法:选择2020年10月至12月河北医科大学第三医院健康体检中心的体检者3 770例，MAFLD诊断依据亚太MAFLD临床诊疗指南。肝脂肪变程度依据超声影像学分为轻、中、重度，对比分析MAFLD患者及健康对照人群UAP、临床特征指标、血清生物化学指标、肝脂肪变特征及相关因素。采用logistic回归分析影响MAFLD肝脂肪变进展的独立危险因素并建立诊断模型，通过受试者操作特征曲线（ROC）评估UAP及新建模型诊断MAFLD的临床效能。多组间均数比较采用单因素方差分析；非正态分布计量资料2组比较采用Mann-Whitney U检验，多组间比较采用秩和检验；计数资料组间比较采用 χ2检验。 结果:3 770例健康体检者中MAFLD 650例，患病率17.24%，以60～69岁最高，达37.23%；男性患病率显著高于女性（30.34%与9.17%），年龄性别分析显示男性30～69岁患病率达38.26%，女性60岁以上人群患病率达31.94%。MAFLD患者UAP显著高于健康对照（278.55 dB/m与220.90 dB/m， Z=-12.592， P<0.001，），且随肝脂肪变程度加重呈递增趋势，轻、中、重度肝脂肪变依次为257.20 dB/m、286.20 dB/m及315.00 dB/m。UAP诊断MAFLD轻、中、重度肝脂肪变的界值依次为243≤UAP＜258 dB/m、258≤UAP＜293 dB/m、≥293 dB/m，灵敏度依次为67.20%、93.60%、95.90%，特异度依次为82.10%、72.00%、84.80%。UAP、丙氨酸转氨酶、空腹血糖为MAFLD肝脂肪变进展的独立危险因素，联合建立MAFLD分级模型（UAG模型），诊断MAFLD轻、中、重度肝脂肪变的ROC曲线下面积依次为0.906、0.907、0.946，灵敏度依次为76.50%、82.10%、98.00%，特异度依次为90.80%、83.30%、76.10%。 结论:MAFLD为普通人群常见疾病，30岁以上男性及老年女性为高发人群；UAP可作为评估MAFLD肝脂肪变的新型无创诊断技术，UAG模型对MAFLD及相关代谢紊乱有较好的诊断效能，可用于指导临床诊断与预后评估。

abstractsObjective:To evaluate the efficacy, establish a diagnostic model, and value of ultrasound attenuation parameters (UAP) to diagnose hepatic steatosis in metabolic dysfunction-associated fatty liver disease (MAFLD) and its relevant disorders.Methods:3770 cases were selected from the Health Examination Center of the Third Hospital of Hebei Medical University between October to December 2020. MAFLD diagnosis was based on the Asia-Pacific region MAFLD clinical diagnosis and treatment guidelines. The degree of hepatic steatosis was divided into mild, moderate and severe according to ultrasound imaging. UAP, clinical characteristic indexes, serum biochemical indexes, characteristics of hepatic steatosis and related factors were compared and analyzed in MAFLD patients and healthy controls. Logistic regression method was used to analyze the independent risk factors affecting the progression of hepatic steatosis in MAFLD to establish the diagnostic model. The clinical efficacy of UAP and the new model in diagnosing MAFLD was evaluated by the receiver operating characteristic curve (ROC). One-way ANOVA was used to compare means among multiple groups. Mann-Whitney U test was used to compare non-normally distributed measurement data between the two groups, and rank-sum test was used to compare multiple groups. χ2 test was used to compare count data between groups. Results:Among the 3 770 cases, 650 were MAFLD, with a prevalence rate of 17.24%, and the highest prevalence was 37.23% in the age group of 60-69. The prevalence rate was significantly higher in male than female (30.34% vs. 9.17%). Age-sex analysis showed that the prevalence rate in males aged 30-69 years was 38.26%, and that in females aged over 60 years was 31.94%. UAP was significantly higher in patients with MAFLD than healthy controls (278.55 dB/m vs. 220.90 dB/m, Z=-12.592, P＜0.001), and an increasing trend with increased degree of hepatic steatosis (mild:257.20 dB/m, moderate:286.20 dB/m, and severe: 315.00 dB/m) were observed. The cut-off values of UAP for the diagnosis of mild, moderate and severe hepatic steatosis were 243≤UAP＜258 dB/m, 258≤UAP＜293 dB/m, ≥293 dB/m in MAFLD. The sensitivity and specificity were 67.20%, 93.60%, 95.90%, and 82.10%, 72.00%, and 84.80%, respectively. UAP, alanine aminotransferase and fasting blood glucose were independent risk factors for the progression of hepatic steatosis in MAFLD. The combined MAFLD classification model (UAG model) was established. The AUC of mild, moderate and severe hepatic steatosis in MAFLD were 0.906, 0.907, and 0.946, respectively, and the sensitivity and specificity were 76.50%, 82.10%, 98.00%, and 90.80%, 83.30% and 76.10%, respectively. Conclusion:MAFLD is a common disease in the general population, with a higher incidence in male and elderly female over 30 years of age. UAP can be used as a new noninvasive diagnostic technique to evaluate hepatic steatosis in MAFLD. The UAG model has a good diagnostic efficacy on MAFLD and its relevant disorders, and thus can be used as a guide for evaluating clinical diagnosis and prognosis.