The diagnostic value of urine pH, serum uric acid, and related clinical indicators for urinary infection stones and the construction of a nomogram model
10.3760/cma.j.cn112330-20240119-00028
- VernacularTitle:尿pH值、血尿酸及相关临床指标对尿路感染性结石的诊断价值及其列线图模型的构建
- Author:
Jinhong SHEN
1
;
Yang DONG
1
;
Yan ZHAO
1
;
Xitao WANG
1
;
Xuanming ZHANG
1
;
Guangyuan ZHU
1
;
Conghui HAN
1
Author Information
1. 徐州医科大学徐州临床学院 徐州市中心医院泌尿外科；徐州 221009
- Publication Type:Journal Article
- Keywords:
Urinary calculi;
Infection;
Urine pH;
Uric acid;
Diagnosis;
Nomogram
- From:
Chinese Journal of Urology
2024;45(11):852-859
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the diagnostic value of urine pH, serum uric acid and related clinical indicators in the diagnosis of urinary infection stones, and to construct a prediction nomogram.Methods:The clinical data of 432 patients with urinary calculi admitted to Xuzhou Central Hospital from August 2018 to November 2023 were retrospectively analyzed. The study included 289 males and 143 females, with an average age of (52.72±13.46) years old. Among the patients, there were 98 cases of hypertension, 67 cases of diabetes, and 100 cases of recurrent calculi. Kidney stones were present in 152 cases, ureteral stones in 242 cases, and bladder stones in 38 cases. Urine bacterial culture yielded positive results in 97 cases. According to the results of postoperative stone composition analysis, the two groups were categorized as infection and no-infection stone groups, and the differences in general data between the two groups were compared. Univariate and multivariate logistic regression analysis were conducted to assess the diagnostic value of urine pH, serum uric acid, and related clinical indicators for urinary infection stones. Receiver operating characteristic (ROC) curve and area under curve (AUC) were utilized to evaluate the clinical significance of urine pH, serum uric acid, and combined indexes in preoperatively diagnosing urinary infection stones, as well as constructing a nomogram prediction model.Results:There were 127 cases of infection stones and 305 cases of no-infection stones. The infection stone group exhibited a higher urine pH value [7.0(6.5, 7.5) vs. 6.0(5.5, 6.5), P<0.001], lower serum uric acid levels [(301.38±70.12) vs. (358.88±88.99) μmol/L, P<0.001], a higher proportion of females [55.1%(70/127) vs. 23.9%(73/305), P<0.001], younger age [(48.36±14.83)vs. (53.12±12.61)years old, P<0.001], a higher proportion of recurrence stones [34.6 %(44/127) vs. 18.4%(56/305), P<0.001], and a higher rate of positive urine bacteria culture[29.9%(38/127)vs. 19.3%(59/305), P=0.016]and nitrite test results [18.9%(24/127)vs. 6.3%(19/305), P <0.001]. Univariate logistic regression analysis revealed that urine pH value, serum uric acid levels, gender, age, recurrent stones, urine bacterial culture, and urine nitrite were associated with urinary infection stones ( P< 0.05). Multivariate logistic regression analysis revealed that urine pH value ( OR= 4.836, 95% CI 3.342-6.997), female gender( OR=2.320, 95% CI 1.286-4.186), recurrent stones ( OR=2.225, 95% CI 1.208-4.101), positive urine bacterial culture ( OR=2.061, 95% CI 1.094-3.883), serum uric acid ( OR=0.992, 95% CI 0.949-0.989), age ( OR=0.969, 95% CI 0.949-0.990) were independent risk factors for urinary infection stones ( P<0.05). The combined diagnostic value of six indicators was the highest, with an AUC of 0.874 (95% CI 0.837-0.911). Following this, urine pH exhibited an AUC of 0.818 (95% CI 0.778-0.858), while serum uric acid had an AUC of 0.704 (95% CI 0.652-0.756). The nomogram model was successfully constructed based on the six indicators. The mean AUC of the ROC curve after 1 000 resamples of the Bootstrap method was 0.864 (95% CI 0.828-0.900), and the calibration curve showed that the predicted curve fit the ideal curve well, with a mean absolute error of 0.005 and a Hosmer-Lemeshow test of P>0.05. Clinical decision curve analysis (DCA) showed that the model had a higher net clinical benefit when the model had a threshold probability value≥0.01. Conclusions:Urine pH and serum uric acid are closely related to urinary infection stones. A nomogram model combining these factors with gender, age, recurrent stones, and urine culture results can effectively predict the probability of infection-related stones, providing significant clinical value.
