Peng Tian-Wen, Zuo Yi, Chen Jin-Guo, Zhang Hai-Bo, Zhang Yan-Hong, Xu Gui-Qi, Zhao Shan-Chao
Department of Urology, Nanfang Hospital / The First School of Clinical Medicine, Southern Medical University, Guangzhou, Guangdong 510515, China.
Zhonghua Nan Ke Xue. 2020 May;26(5):399-408.
To analyze vascular damage-related risk factors for ED in patients with type 2 diabetes mellitus (DM) and develop a nomogram for the prediction of the factors.
A total of 181 patients with type 2 DM were included for sexual function assessment, and the clinical data on vascular damage were retrieved from the patients system. After preprocessing, the data were described by the number and percentage of different types of cases and subjected to statistical analysis with the R software. The Lasso regression model was used to optimize feature selection. On the premise of the sample size required for logistic regression analysis according to the number of events per variable, multivariable logistic regression analysis was performed on the selected variables and a nomogram was developed for diabetes-induced erectile dysfunction (DIED). Then, the performance of the nomogram was evaluated with respect to its calibration, discrimination and clinical utility using Harrell's concordance index (C-index), the calibration plot and decision curve analysis, as well as bootstrapping for internal validation.
ED was diagnosed in 90 (49.7%) of the 181 patients. The risk factors subjected to logistic regression analysis included the duration of DM (OR = 4.440, 95% CI: 1.594－13.105; OR = 7.667, 95% CI: 1.444－48.733), status of carotid intima-media thickness (c-IMT) (OR = 3.767, 95% CI: 1.194－12.691), diabetic retinopathy (DR) (OR = 5.382, 95% CI: 1.373－28.301), diabetic kidney disease (DKD) (OR = 4.959, 95% CI: 1.156－27.728), low-density lipoprotein cholesterol (LDL-C) (OR = 8.210, 95% CI: 2.027－43.507), red blood cell distribution width (RDW) (OR = 2.418, 95% CI: 1.021－5.826), and plasma fibrinogen (Fbg) (OR = 4.649, 95% CI: 2.001－11.339). The C-index of the DIED model was 0.911 (95% CI: 0.869－0.954). The curve representing the performance of the nomogram fit in well with that representing a perfect prediction by the calibration plot. Decision curve analysis indicated that the nomogram was clinically useful for predicting DIED in the type 2 DM patients at the possibility threshold of 6% to 93%.
A nomogram was preliminarily developed for predicting the risk of DIED in type 2 DM patients with respect to the seven independent influencing factors, including the duration of DM, status of c-IMT, DR, DKD, LDL-C, RDW, and Fbg.
分析2型糖尿病（DM）患者勃起功能障碍（ED）的血管损伤相关危险因素，并建立预测这些因素的列线图。
共纳入181例2型DM患者进行性功能评估，并从患者系统中检索血管损伤的临床资料。预处理后，数据用不同类型病例的数量和百分比进行描述，并使用R软件进行统计分析。采用Lasso回归模型优化特征选择。根据每个变量的事件数进行逻辑回归分析所需的样本量，对所选变量进行多变量逻辑回归分析，并建立糖尿病性勃起功能障碍（DIED）的列线图。然后，使用Harrell一致性指数（C指数）、校准图和决策曲线分析以及自举法进行内部验证，评估列线图在校准、区分度和临床实用性方面的性能。
181例患者中，90例（49.7%）诊断为ED。进行逻辑回归分析的危险因素包括DM病程（OR = 4.440，95%CI：1.594－13.105；OR = 7.667，95%CI：1.444－48.733）、颈动脉内膜中层厚度（c-IMT）状态（OR = 3.767，95%CI：1.194－12.691）、糖尿病视网膜病变（DR）（OR = 5.382，95%CI：1.373－28.301）、糖尿病肾病（DKD）（OR = 4.959，95%CI：1.156－27.728）、低密度脂蛋白胆固醇（LDL-C）（OR = 8.210，95%CI：2.027－43.507）、红细胞分布宽度（RDW）（OR = 2.418，95%CI：1.021－5.826）和血浆纤维蛋白原（Fbg）（OR = 4.649，95%CI：2.001－11.339）。DIED模型的C指数为0.911（95%CI：0.869－0.954）。列线图性能曲线与校准图中完美预测的曲线拟合良好。决策曲线分析表明，在6%至93%的可能性阈值下，列线图对预测2型DM患者的DIED具有临床实用性。
初步建立了一个列线图，用于预测2型DM患者发生DIED的风险，涉及7个独立影响因素，包括DM病程、c-IMT状态、DR、DKD、LDL-C、RDW和Fbg。
