RESUMO
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.