Metabolic abnormalities, recurrence risk, patient and stone characteristics in calcium-based pediatric stone formers: is there any association?

PURPOSE: To assess the association between serum and urinary metabolic abnormalities, stone recurrence risk, and patient and stone characteristics in calcium-based pediatric stone formers; aiming to refine the indication for metabolic evaluation in pediatric urolithiasis population. PATIENTS AND

METHODS

The study included 80 pediatric patients < 18 years with a history of intervention for calcium-based stones at the Urology and Nephrology Center, Mansoura University, Egypt, between 2001 and 2022. Electronic database was reviewed for patient and stone characteristics. Serum and 24-hour urinary metabolic evaluation was done. The primary outcome was to assess the association between serum and urinary metabolic abnormalities, and patient and stone characteristics. A secondary outcome was to assess risk factors associated with stone recurrence.

RESULTS

Serum and urinary metabolic abnormalities were present in 31.25% and 73.75% of the study population, respectively. There was no significant difference between normal and abnormal groups of serum and 24-hour urine chemistry in relation to all assessed patient and stone characteristics. However, there was a significant association between stone laterality and risk of recurrence (HR: 3.801, 95% CI: 1.239–11.662, p = 0.02); being ~ 3.8 times higher with bilateral urolithiasis (78.3% vs. 21.8% with unilateral urolithiasis).

CONCLUSION

Routine serum and 24-hour urinary metabolic evaluation is still indicated in all pediatric calcium-based stone formers; being a high-risk population. However, the recurrence risk is higher in patients with bilateral urolithiasis. So, in case of limited resources, metabolic evaluation could be restricted to this group of patients only.