Objective: To investigate the levels of β-amyloid 1-42 (Aβ1-42) and total bilirubin (TBIL) in serum of patients with Alzheimer 's disease (AD) and the relationship between them. Methods: A case-control study was conducted to select 73 patients with AD who were hospitalized in Beijing Huilongguan Hospital from November 2023 to February 2024 as AD group, and 70 healthy controls (HC) were selected as HC group. The basic information of all subjects and the clinical information of AD patients were collected, and the levels of Aβ1-42 and TBIL were detected and compared between the two groups. The effects of Aβ1-42 and TBIL on AD were analyzed by binary logistic regression. Correlation analysis was used to analyze the relationship between TBIL and Aβ1-42 in AD group and HC group. According to the level of Aβ1-42 in AD patients, they were divided into Aβ1-42 elevated group and Aβ1-42 normal group. The differences of clinical data and TBIL levels between the two groups were compared. According to the quartile of TBIL in AD patients, they were divided into Q1 group, Q2 group, Q3 group and Q4 group. The correlation between TBIL and the risk of Aβ1-42 elevation was analyzed by binary logistic regression. The receiver operating characteristic (ROC) curve was drawn to analyze the ability of TBIL level to predict the increase of Aβ1-42 in AD patients. Results: There was no significant difference in gender, marital status, education level, smoking and drinking between AD group and HC group (P>0.05), while the levels of Aβ1-42 and TBIL and age in AD group were significantly higher than those in HC group [101.10(71.20, 128.60) pg/ml/22.40(10.00, 39.60) pg/ml, Z=-8.714, P<0.001;(11.00±3.22/8.07±3.00) μmol/L, t=5.621, P<0.001;(77.14±8.20/68.30±10.27) years, t=5.672, P<0.001]. For AD patients, the TBIL level in the Aβ1-42 elevated group was lower than that in the Aβ1-42 normal group [(10.05±2.94/11.66±3.28) μmol/L, t=-2.148, P=0.035], while there was no significant difference in other demographic and clinical data between the two groups (P>0.05). Binary logistic regression analysis showed that higher levels of Aβ1-42 (OR=1.021, 95%CI：1.010-1.032) and TBIL (OR=1.505, 95%CI：1.249-1.814), older age (OR=1.083, 95%CI：1.020-1.150) and female (OR=4.348, 95%CI：1.253-15.094) were risk factors for AD. Correlation analysis showed that TBIL was negatively correlated with Aβ1-42 in AD patients (r=-0.322, P=0.006). After adjusting the relevant covariates, binary logistic regression showed that compared with AD patients in Q1 group, the risk of Aβ1-42 elevation in AD patients in Q4 group was lower (OR=0.052, 95%CI：0.005-0.535, P<0.05), and TBIL was negatively correlated with the risk of Aβ1-42 elevation (P trend<0.05). ROC curve showed that the area under the curve (AUC) of TBIL in predicting the increase of Aβ1-42 in AD patients was 0.642. Conclusion: The levels of Aβ1-42 and TBIL in AD patients were higher, and the level of TBIL was negatively correlated with the risk of Aβ1-42 elevation.
目的： 探讨β-淀粉样蛋白1-42（Aβ1-42）和总胆红素（TBIL）在阿尔茨海默病（AD）患者血清中的水平及两者之间的关系。 方法： 采用病例对照研究，选取2023年11月至2024年2月于北京回龙观医院住院治疗的73例AD患者作为AD组，另选取同期70名健康对照者（HC）作为HC组。收集所有受试者基本信息和AD患者临床信息，同时检测Aβ1-42和TBIL水平，在两组之间进行比较，并通过二元logistic回归分析Aβ1-42和TBIL对AD的影响。采用相关分析法分别在AD组和HC组分析TBIL和Aβ1-42的关系。根据AD患者Aβ1-42水平分为Aβ1-42升高组和Aβ1-42正常组，比较两组临床资料和TBIL水平的差异。依据AD患者TBIL四分位数将其分为Q1组、Q2组、Q3组和Q4组，通过二元logistic回归分析TBIL与Aβ1-42升高风险的相关性。绘制受试者工作特征（ROC）曲线分析AD患者TBIL水平预测Aβ1-42升高的能力。 结果： AD组和HC组之间性别、婚姻状况、受教育水平、吸烟和饮酒比较差异无统计学意义（P>0.05），而AD组Aβ1-42和TBIL水平以及年龄均显著高于HC组［101.10（71.20，128.60）pg/ml/22.40（10.00，39.60）pg/ml， Z=-8.714，P<0.001；（11.00±3.22/8.07±3.00）μmol/L， t=5.621，P<0.001；（77.14±8.20/68.30±10.27）岁， t=5.672，P<0.001］。AD患者Aβ1-42升高组的TBIL水平低于Aβ1-42正常组［（10.05±2.94/11.66±3.28）μmol/L， t=-2.148，P=0.035］，而其他人口学和临床资料两组比较差异均无统计学意义（P>0.05）。二元logistic回归分析提示较高水平的Aβ1-42（OR=1.021，95%CI：1.010~1.032）和TBIL（OR=1.505，95%CI：1.249~1.814）以及高龄（OR=1.083，95%CI：1.020~1.150）和女性（OR=4.348，95%CI：1.253~15.094）是AD发生的危险因素。相关分析显示AD患者TBIL与Aβ1-42呈负相关（r=-0.322，P=0.006）。调整相关协变量后，二元logistic回归显示，与Q1组AD患者相比Q4组AD患者发生Aβ1-42升高的风险降低（OR=0.052，95%CI：0.005~0.535，P<0.05），且TBIL与Aβ1-42升高风险呈负相关（P趋势<0.05）。ROC曲线显示AD患者TBIL预测Aβ1-42升高的曲线下面积（AUC）为0.642。 结论： AD患者Aβ1-42和TBIL水平较高，且TBIL水平与Aβ1-42升高风险呈负相关。.