Comparison of metabolic parameters between pure-uric acid and mixed-uric acid kidney stone formers.

PURPOSE: We seek to compare clinical and 24-h urine parameters between pure-uric acid (UA) and UA-CaOx stone formers in our practice and explore how any differences in metabolic profiles could suggest different prevention strategies between the two groups. METHODS: We retrospectively reviewed patients with either pure- or mixed-UA nephrolithiasis from 2020 to 2023 at a tertiary care center. We included patients with a 24-h urine collection and a stone analysis detecting any amount of UA. Patients were organized into two cohorts: (1) those with 100% UA stones and (2) < 100% UA stones. Differences in demographic characteristics were compared between pure-UA and UA-CaOx stone formers. Twenty-four hour urine metabolic parameters as well as metabolic abnormalities were compared between the pure-uric acid and mixed-uric acid groups. RESULTS: We identified 33 pure-UA patients and 33 mixed-UA patients. Patient demographics were similar between the groups (Table 1). Pure- and mixed-UA patients had a similar incidence of metabolic syndrome, diabetes, history of stones, and stone burden. Table 1 Demographic and baseline characteristics among pure- and mixed-uric acid stone formers Pure-uric acid stones (n = 33) Mixed-uric acid stones (n = 33) p-value Median age [IQR] 63.00 [58.00-72.50] 63.00 [53.50-68.00] 0.339 Median BMI [IQR] 28.79 [25.81-33.07] 27.96 [25.81-29.55] 0.534 Gender, n (%) 1.000  Male 21 (63.6) 21 (63.6)  Female 12 (36.4) 12 (36.4) Metabolic syndrome, n (%) 17 (51.5) 16 (48.5) 0.806 Diabetes, n (%) 13 (39.4) 12 (36.4) 0.800 History of stones, n (%) 23 (69.7) 22 (66.7) 0.792 Median total stone burden, mm [IQR] 12.00 [6.00-26.50] 13.00 [7.05-20.00] 0.995 Median serum uric acid, mg/dL [IQR] 6.20 [4.80-7.15] 5.90 [4.98-6.89] 0.582 IQR Interquartile range BMI Body Mass Index n number We found the pure-UA cohort to have 24-h lower urine volume (1.53 vs. 1.96 L/day, p = 0.045) and citrate levels (286 vs. 457 mg/day, p = 0.036). UA-CaOx stone formers had higher urinary calcium levels (144 vs. 68 mg/day, p = 0.003), higher urinary oxalate levels (38 vs. 30 mg/day, p = 0.017), and higher median urinary calcium oxalate super-saturation (3.97 vs. 3.06, p = 0.047). CONCLUSIONS: Pure-UA kidney stone formers have different urinary metabolic parameters when compared with UA-CaOx stone formers, thus requiring different and tailored medical management.

[Urine metabolomics study of hepatocellular carcinoma].

Objective: To investigate the urinary small molecular metabolites and their metabolic characteristics of patients with hepatocellular carcinoma (HCC). Methods: High throughput ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) was used to detect the small molecular metabolites in urine of healthy control (n=10), patients with hepatic hemangioma (n=10) and patients with HCC (n=10). The orthogonal projections to latent structures-discriminant analysis (OPLS-DA), hierarchical cluster analysis of multivariate analysis and univariate analysis were used to analyze the differential metabolites of the three groups. Results: The metabolic profiles of the three groups showed that the total of 381 differential metabolites were identified and divided into 96 up-regulated metabolites and 285 down-regulated metabolites. There were 55 urinary metabolites specifically related to HCC. Twenty-one of them were significantly up-regulated, including Acetyl-DL-Leucine, Ala Asp, HoPhe-Gly-OH, while 34 were significantly down-regulated, including Selenocystathionine, Met Trp Met Cys, Valsartan acid and so on. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that the differential metabolites were mainly enriched in glutamine/glutamate metabolism, lysine biosynthesis, tricarboxylic acid cycle and purine metabolism. Conclusions: The occurrence of HCC is accompanied by the abnormalities of multiple metabolites and metabolic pathways. The analysis of the characteristic metabolic profile of urine in patients with HCC is helpful to find metabolic markers and potential therapeutic targets for liver cancer.

Comparison of measurement results of citric acid, oxalic acid, and phosphoric acid in 24-hour urine preserved with thymol and concentrated hydrochloric acid / 中华泌尿外科杂志

Objective:To compare the differences in the results of 24-hour urine citric acid, oxalic acid, and phosphoric acid detection between thymol and concentrated hydrochloric acid preserved urine.Methods:Urine samples were collected from 50 patients with upper urinary tract stones who were admitted to the Second Affiliated Hospital of Zhengzhou University from July 2023 to August 2023. There were 38 males and 12 females, with the age of (45.52 ± 13.68) years old. On the second day of admission, patients were required to empty their bladders in the morning and collect urine over a 24-hour period. The urine was evenly divided and stored in two sealed plastic containers. In one container, concentrated hydrochloric acid (15 ml, concentration of 6 mmol/L) was added as a preservative, forming the hydrochloric acid group. In the other container, 2 g of thymol was added as a preservative, forming the thymol group. The concentration of oxalic acid, citric acid, and phosphoric acid in urine were measured, and the measurement results were multiplied by the total amount of urine to obtain the final measurement results. The differences in the measurement results of citric acid, oxalic acid, and phosphoric acid between two groups were compared.Results:In the concentrated hydrochloric acid group, the median value of citric acid was 160.87(95.37, 245.61) mg/24h, the median value of oxalic acid was 33.09(26.32, 39.37) mg/24h, and the mean value of phosphoric acid was (731.06 ± 240.62) mg/24h. In the thymol group, the median value of citric acid was 340.40(166.56, 561.77) mg/24h, the median value of oxalic acid was 33.91(26.51, 44.56) mg/24h, and the mean value of phosphoric acid was (759.07 ± 273.23) mg/24h. Compared with the thymol group, the citric acid level in the concentrated hydrochloric acid group was significantly lower ( Z=4.31, P< 0.001), but there was no significant difference in oxalic acid ( Z=0.85, P=0.393) and phosphoric acid ( t=1.65, P=0.106) between the two groups. Conclusions:Compared with thymol, the results of 24 h urine citric acid with concentrated hydrochloric acid as preservative is lower, but there is no significant difference between oxalic acid and phosphoric acid.The use of thymol as a preservative may be more suitable than concentrated hydrochloric acid for the detection of citric acid, oxalic acid and phosphoric acid in 24-hour urine metabolism analysis.

Differential analysis of urinary metabolic abnormalities in patients with different subtypes of calcium oxalate stones / 中华泌尿外科杂志

Objective:To investigate the difference of 24h urinary metabolic abnormalities in patients with different subtypes of calcium oxalate stones.Methods:The clinical data of 120 patients with simple calcium oxalate stones admitted to the Second Affiliated Hospital of Zhengzhou University from March 2018 to May 2020 were retrospectively analyzed.There were 90 males (75.0%) and 30 females (25.0%), with the age of (49.1 ±13.5) years old, and body mass index (BMI) of (24.6 ±3.0) kg/m 2. There were 23 cases of diabetes mellitus (19.2%), 8 cases of coronary heart disease (7.0%), 36 cases of hypertension (30.0%) and 45 cases of gastrointestinal diseases (37.5%). There were 11 cases (9.2%) of low pH, 54 cases (45.0%) of hyperoxaluria, 19 cases (15.8%) of hypercalcemia, 72 cases (60.0%) of hypocitrouria, 3 cases (2.5%) of hyperuricuria, and 18 cases (15.0%) of hyperuricemia. In the 120 patients, 79 underwent ureteral soft lithotripsy, 28 underwent percutaneous nephrolithotomy, and 13 underwent extracorporeal shock wave lithotripsy. The patients were divided into calcium oxalate monohydrate stone group (COM group) and calcium oxalate dihydrate stone group (COD group). The general clinical data and urinary metabolic data of the two groups were compared. Independent risk factors for stone formation of the two groups were analyzed. Results:There were 120 cases in this study, with 90 cases in COM group and 30 cases in COD group. Urinary oxalic acid in COM group and COD group was 41.3 (30.1, 54.2) mg and 34.1 (26.6, 39.9) mg, respectively, and the difference was statistically significant ( P=0.01). The incidence of hyperoxaluria was 52.2% (47 cases) and 23.3% (7 cases), respectively, and the difference was statistically significant ( P<0.01). Urinary calcium in COD group and COM group was 6.8 (6.1, 8.8) mmol and 4.0 (2.3, 5.2) mmol, respectively, and the difference was statistically significant ( P<0.01). The incidence of hypercalcemia was 43.3% (13 cases) and 6.7% (6 cases), respectively, the difference was statistically significant ( P<0.01). The urinary phosphate in COM group and COD group was 2 063.5 (1 688.8, 2 803.2) mg and 1 231.7 (766.7, 1 740.9) mg, respectively, and the difference was statistically significant ( P<0.01). The serum uric acid level in COM group and COD group was (343.0±111.7)μmol/L and (297.6±77.6)μmol/L, respectively, and the difference was statistically significant ( P<0.05). There were no significant differences in term of age, gender, body mass index, diabetes mellitus, coronary heart disease, hypertension, gastrointestinal disease, parathyroid hormone (PTH), hemoglobin, serum creatinine, serum potassium, serum phosphorus, serum calcium, serum sodium, stone load and side between the two groups ( P>0.05). There were no significant differences in urinary sodium, urinary phosphorus, urinary magnesium, urinary citric acid and urinary uric acid levels between the two groups ( P>0.05). Binary Logistic regression analysis showed that hyperoxaluria was an independent risk factor for COM patients ( OR=4.859, P<0.01). Increased urinary phosphoric acid level was an independent risk factor for COM patients ( OR=1.001, P<0.01). Hypercalcemia was an independent risk factor for COD patients ( OR=27.856, P<0.01). Conclusions:COM calculus patients have higher urinary oxalic acid and urinary phosphoric acid levels, and are more likely to have hyperoxaluria. COD calculus patients have higher urinary calcium levels and are more likely to develop hypercalcemia.

Urine metabolomics study of hepatocellular carcinoma / 中华肿瘤杂志

Objective: To investigate the urinary small molecular metabolites and their metabolic characteristics of patients with hepatocellular carcinoma (HCC). Methods: High throughput ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) was used to detect the small molecular metabolites in urine of healthy control (n=10), patients with hepatic hemangioma (n=10) and patients with HCC (n=10). The orthogonal projections to latent structures-discriminant analysis (OPLS-DA), hierarchical cluster analysis of multivariate analysis and univariate analysis were used to analyze the differential metabolites of the three groups. Results: The metabolic profiles of the three groups showed that the total of 381 differential metabolites were identified and divided into 96 up-regulated metabolites and 285 down-regulated metabolites. There were 55 urinary metabolites specifically related to HCC. Twenty-one of them were significantly up-regulated, including Acetyl-DL-Leucine, Ala Asp, HoPhe-Gly-OH, while 34 were significantly down-regulated, including Selenocystathionine, Met Trp Met Cys, Valsartan acid and so on. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that the differential metabolites were mainly enriched in glutamine/glutamate metabolism, lysine biosynthesis, tricarboxylic acid cycle and purine metabolism. Conclusions: The occurrence of HCC is accompanied by the abnormalities of multiple metabolites and metabolic pathways. The analysis of the characteristic metabolic profile of urine in patients with HCC is helpful to find metabolic markers and potential therapeutic targets for liver cancer.