Correlation Between Stone Composition and Serum Metabolic Abnormalities in Recurrent Renal Calculi

BACKGROUND: Renal stone disease is one of the most prevalent urological conditions, often resulting from a complex interplay of metabolic, dietary, and environmental factors. Despite its multifactorial origins, recurrent renal calculi continue to pose a significant burden in urology. Identifying underlying biochemical abnormalities is essential to developing preventive strategies aimed at reducing the risk of recurrence. OBJECTIVE: To assess the discrepancy between renal calculi composition and serum biochemical anomalies to determine the metabolic abnormalities indicative of recurrent renal calculi. METHODS: This prospective observational study was conducted at District Headquarter Hospital, Mardan, Pakistan, over a two-year period (February 2022 to January 2024) on 120 consecutive adult patients with recurrent renal or ureteric stones. The study included analyses of serum calcium, phosphate, uric acid, vitamin D, parathyroid hormone (PTH), and bicarbonate levels. Stones were analyzed using Fourier-transform infrared spectrography after being surgically removed or voided. The clinical correlation between the biochemical serum anomaly, type of calculi, and recurrence was evaluated using the chi-square test and logistic regression models. RESULTS: The most common composition of stones was calcium oxalate, constituting 53.3% of the total number of stones, followed by mixed calcium oxalate-phosphate and uric acid stones, constituting 23.3% and 13.3%, respectively. Metabolically, the most common abnormalities were vitamin D deficiency (55.8% of participants), followed by hyperuricemia (18.3%) and hypercalcemia (11.7%). Uric acid stones were significantly influenced by serum uric acid levels (p < 0.001), and vitamin D deficiency was associated with mixed calcium oxalate-phosphate stones (p = 0.032). CONCLUSION: The presence of particular serum metabolic abnormalities is significantly associated with specific stone compositions as well as with particular patterns of recurrence. Addressing recurrent renal stone disease sufficiently should include a thorough metabolic evaluation and correction of vitamin D deficiency and hyperuricemia, along with other modifiable metabolic derangements, to minimize the occurrence of future stones.