MO128: Predisposing Metabolic Factors to Urinary System Stone Formation in Patients with Autosomal Dominant Polycystic Kidney Disease
Authors: Chasan Onour , Serra Ucar Ayse , Gursu Meltem , Mirioglu Safak , Kazancioglu Rumeyza , Celal Elcioglu Omer 
Published: May 2022

Abstract

BACKGROUND AND AIMS
The risk of urinary tract stone formation in patients with autosomal dominant polycystic kidney disease (ADPKD) is 20%, twice as high as in the normal population. The most important reason for this increased tendency to stone disease is thought to be anatomic changes in the kidney. To investigate metabolic factors that predispose to urinary system stone formation in individuals with ADPKD.

METHOD
A total of 180 volunteers who applied to our outpatient clinic between December 2019 and May 2021 were included in the study. Four groups were formed: patients with ADPKD and urinary system stones (ADPKD + STONE) (n = 42), patients with ADPKD but no stones (ADPKD + STONE FREE) (n = 43), stone patients without ADPKD (STONE) (n = 47) and healthy controls (HEALTHY) (n = 48) groups. Spot urine pH, 24-h urine volume, calcium, uric acid, oxalate, citrate, sodium and magnesium parameters were measured. STONE group data were obtained retrospectively. Along with these parameters, serum electrolyte, parathormone (PTH), ferritin, albumin, creatinine, urea and uric acid values were also compared. A P value of &lt;.05 was considered significant for statistical analysis.

RESULTS
There was no statistically significant difference between the four groups in terms of age and gender (P &gt; .05). The citrate value in 24-h urine was significantly lower in the ADPKD + STONE and ADPKD + STONE-FREE groups than the STONE and HEALTHY groups (P &lt; .05). The citrate value in the 24-h urine was significantly lower in the STONE group than in the HEALTHY group (P &lt; .05). The citrate value in 24-h urine did not differ significantly between the ADPKD + STONE and ADPKD + STONE FREE groups (P &gt; .05). In the ADPKD + STONE and ADPKD + STONE-FREE groups, the 24-h urinary calcium value was significantly lower than the STONE and HEALTHY groups (P &lt; .05). In the STONE group, the 24-h urinary calcium value was significantly higher than the HEALTHY group (P &lt; .05). There was no significant difference in the 24-h urinary calcium value between the ADPKD + STONE and ADPKD + STONE FREE groups (P &gt; .05). The uric acid level in 24-h urine was significantly lower in the ADPKD + STONE and ADPKD + STONE-FREE groups than in the HEALTHY group (P &lt; .05). The uric acid value in the 24-h urine did not differ significantly between the ODPBH + STONE, ADPKD + STONE-FREE and STONE groups (P &gt; .05). The uric acid value in 24-h urine did not differ significantly between the STONE and HEALTHY groups (P &gt; .05). Oxalate, sodium and magnesium values in 24-h urine and 24-h urine volume did not differ significantly between the groups (P &gt; .05). Urine pH value was significantly lower in the ADPKD + STONE, ADPKD + STONE-FREE and STONE groups than in the HEALTHY group (P &lt; .05). The pH value did not differ significantly between ADPKD + STONE, ADPKD + STONE-FREE and STONE groups (P &gt; .05).
Serum PTH values were significantly higher in the ADPKD + STONE and ADPKD + STONE-FREE groups than in the HEALTHY group (P &lt; .05). The PTH values did not differ significantly between the STONE and HEALTHY groups (P &gt; .05). PTH values did not differ significantly between ODPBH + STONE, ADPKD + STONE-FREE and STONE groups (P &gt; .05).
There was no significant difference between the groups in terms of serum ferritin, sodium, potassium, calcium, phosphorus, magnesium and uric acid values (P &gt; .05).

CONCLUSION
In our study, 24-h urine citrate level was found to be significantly lower in both ADPKD + STONE and ADPKD + STONE-FREE patients compared to the volunteers in the STONE and HEALTHY groups (P &lt; .05). In conclusion, patients with ADPKD should also be evaluated for hypocitraturia in the outpatient clinic.