Metabolic evaluation in first time and recurrent urinary stone formers: Study from a tertiary care center of India

Kidney stone disease is a common and often debilitating disorder with significant recurrence rate. It is a matter of debate whether the metabolic factors responsible for renal stone formation are similar or variable in different populations around the globe.

To evaluate the metabolic abnormalities via 24 hours urine profiles in first-time and recurrent renal stone formers.

This retrospective study was conducted at a tertiary care center between 2022 and 2024 and included 70 patients with urolithiasis, comprising 30 first-time stone formers and 40 recurrent stone formers (RSF). All patients underwent biochemical evaluation, including serum calcium, phosphorus, uric acid, creatinine, and intact parathyroid hormone levels. A 24-hour urine analysis was performed to assess urinary volume and the excretion of calcium, oxalate, citrate, uric acid, and phosphate. Metabolic abnormalities were defined according to standard criteria. Statistical analysis was performed using the independent t-test for continuous variables and the χ ² test for categorical variables, with a P value < 0.05 considered statistically significant.

Fifty-nine patients (84.2%) had at least one identifiable metabolic risk factor, with 37 patients (52.8%) having two or more metabolic abnormalities. The most common abnormalities detected were hypercalciuria 27 (38.5%) and hyper-oxaluria 19 (27.1%). Low urine volume, hypocitraturia and hyperuricemia was seen in 14 (20%), 16 (22.8%) and 4 (5.7%) patients respectively. Primary hyperparathyroidism was seen in a total of 8 (11.4%) patients. Metabolic abnormalities were seen more commonly in RSF but there was no statistically significant difference (P value > 0.05) in abnormalities between first time and RSF.

Metabolic evaluation reveals they were prevalent in > 70% of both groups, supporting routine evaluation even in first-time formers in high-risk regions. Hypocitraturia, hyperoxaluria, hyperphosphatemia and hyperparathyroidism are present in a significant proportion of Indian stone former patients.