双能量计算机断层扫描评估单钠尿酸盐负荷预测痛风发作风险——前瞻性、观察性队列研究

Dual-energy computed tomography assessment of monosodium urate load predicts gout flare risk—a prospective observational cohort study

目的确定双能量计算机断层扫描(DECT)测量单钠尿酸盐(MSU)晶体的负荷程度能否作为预测痛风急性发作风险的指标。方法本研究为单中心、前瞻性、观察性研究, 纳入2021年8月至2022年2月在青岛大学痛风门诊初诊且通过DECT对双侧足部进行MSU评估的痛风患者229例。入组后, 所有患者开始降尿酸治疗, 并在3个月、6个月时接受随访。在6个月内出现至少1次发作的患者与没有发作的患者进行比较, 计算痛风发作风险的比值比(OR)。结果与无痛风发作患者相比, 痛风发作患者的病程[(6.69±5.42)对(4.14±4.86)年, P<0.01]、基线前1年发作次数[(4.80±1.73)对(2.02±1.23)次, P<0.01]、合并脂肪肝比例(11.0%对1.4%,P<0.05)、足部MSU晶体体积[(3.52±9.74)对(0.29±0.98)cm^(3),P<0.05]显著增高。多因素logistic回归分析显示基线前1年发作次数(OR=1.295, 95%CI 1.032~1.613,P<0.05)和足部MSU晶体体积(OR=3.245, 95%CI 1.164~9.064,P<0.05)是痛风发作的独立危险因素。受试者工作特征(ROC)曲线显示, 在临床预测模型的基础上加入MSU晶体体积的预测模型建立综合预测模型后, 曲线下面积(AUC)值为0.780(95%CI 0.710~0.840), 灵敏度为0.83, 特异度为0.62。使用Bootstrap法对综合预测模型进行内部验证, 该模型预测痛风急性发作的一致性指数(C-index)为0.770(95%CI 0.701~0.833), 该模型的校准曲线显示模型对痛风急性发作的预测概率能较好拟合实际概率, 校准度高。结论足部MSU晶体体积是降尿酸治疗后痛风急性发作的独立危险因素。足部MSU晶体体积越大, 痛风急性发作的可能性越高。本研究为早期预测痛风发作提供了依据, 为早期预防治疗提供了参考。

Objective:To investigate whether dual-energy computed tomography(DECT)measurement of monosodium urate(MSU)crystal loading can predict the risk of gout flares.Methods:A single-center,prospective,observational study included 229 gout patients initially diagnosed at the Gout Clinic of Qingdao University from August 2021 to February 2022.The patients underwent MSU assessment of the bilateral feet using DECT.Following enrolment,all patients commenced uric acid-lowering therapy(ULT)and were followed up at 3 and 6 months.Patients who experienced at least one flare within 6 months were compared with those who did not,and the odds ratio(OR)for the risk of gout flares was calculated.Results:Patients who experienced gout flare had a significantly longer disease duration[(6.69±5.42)vs(4.14±4.86)years,P<0.01],a higher number of flares in the past year(4.80±1.73 vs 2.02±1.23,P<0.01),a higher proportion of fatty livers(11.0%vs 1.4%,P<0.05),and a greater volume of MSU crystals in the feet[(3.52±9.74)vs(0.29±0.98)cm^(3),P<0.05]compared to patients without gout flare.The results of the multifactorial logistic regression analysis indicated that the number of flares in the past year(OR=1.295,95%CI 1.032-1.613,P<0.05)and feet MSU crystal volume(OR=3.245,95%CI 1.164-9.064,P<0.05)were independent risk factors for gout flares.The receiver operating characteristic(ROC)curve indicated the integration of the MSU prediction model into the clinical prediction model resulted in a comprehensive prediction model with an area under curve(AUC)value of 0.780(95%CI 0.710-0.840),sensitivity of 0.83,and specificity of 0.62.Internal validation of the comprehensive prediction model using the Bootstrap method yielded a C-index of 0.770(95%CI 0.701-0.833)for predicting flares.The calibration curve of the model demonstrated a good fit between the predicted probability of flares and the actual probability,indicating high calibration accuracy.Conclusion:The volume of MSU crystals in the feet is an independent risk factor for flares following ULT.A larger volume of MSU crystals in the foot increases the likelihood of a flare.This study provides a basis for early prediction of flare and a reference for early preventive treatment.