Investigation of predisposing factors for urinary system stone formation in autosomal dominant polycystic kidney disease patients

Aims: Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary cause of end stage renal disease (ESRD). In ADPKD the frequency of urinary system stone increased 2 times compared to the normal population. 20% of ADPKD patients have urinary system stone. Urinary system stone is an important health problem for the normal population and ADPKD patients. Urinary system stone causes renal colic, hamaturia, urinary system infection, postrenal obstruction. The aim of our study is to investigate the metabolic factors that form urinary tract stones in ADPKD patients. We created four groups, ADPKD with urinary system stone (ADPKD+LIT), ADPKD without urinary system stone (ADPKD), urolithiasis patients (CALCULI), healthy control (HEALTHY). Urine pH (spot urine), 24-hour urine volume, 24-hour urine calcium, urate, oxalate, citrate, protein, sodium and magnesium levels were measured from all volunteers. We aimed to compare these parameters between groups. Materials and Methods: Volunteers from ADPKD+LIT, ADPKD and HEALTHY groups who applied to Bezmialem Vakıf University Nephrology clinics and Internal Diseases clinics between December 2019 and May 2021 were prospectively included in the study. İn the CALCULI group Patients who applied to the Nephrology clinics between 2018-2021 study were included retrospectively. 42 patients to ADPKD+LIT group, 43 patients to ADPKD group, 47 patients to CALCULI group, 48 healthy volunteers to HEALTHY group were included in the study. 180 volunteers participated in our study. There was no statistically significant difference between the four groups in terms of age and gender (p> 0.05). Volunteers in ADPKD+LIT, ADPKH and HEALTHY groups collected 24-hour urine. In these three groups, spot urine pH, 24-hour urine volume, 24-hour urine calcium, uric acid, oxalate, citrate, sodium and magnesium parameters were measured. Previously collected 24-hour urine of the patients in the CALCULI group and the same parameters in spot urine (urine pH) were analyzed retrospectively and included in the study. These parameters were compared between the four groups. These parameters were compared between the four groups. In addition, the serum electrolyte, parathormone (PTH), ferritin, albumin, creatinine, urea and uric acid values of the participants in the four groups were also compared. Metabolic factors predisposing to urinary system stones in individuals with ADPKD were investigated with all analyzes of these urine and serum. Statistical analyzes were made by recording the data of the participants in the Statistical Package For Social Sciences for Windows program (SPSS). p <0.05 value was considered significant for statistical analysis. Results: 24-hour urine citrate value was significantly lower in ADPKD+LIT and ADPKD groups than in the CALCULI and HEALTHY groups (p <0.05). 24-hour urine citrate value was significantly lower in the CALCULI group than the HEALTHY group (p <0.05). 24-hour urine citrate value did not differ significantly between ADPKD+LIT and ADPKD groups (p >0.05). 24-hour urine calcium value was significantly lower in ADPKD+LIT and ADPKD groups than in the CALCULI and HEALTHY groups (p <0.05). 24-hour urine calcium level was significantly higher in the CALCULI group than the HEALTHY group (p <0.05). 24-hour urine calcium value did not differ significantly between ADPKD+LIT and ADPKD groups (p >0.05). 24-hour urine urate value was significantly lower in ADPKD+LIT and ADPKD groups than in the HEALTHY group (p <0.05). 24-hour urine urate value did not differ significantly between ADPKD+LIT, ADPKD and CALCULI groups (p >0.05). 24-hour urine urate value did not differ significantly between CALCULI and HEALTHY groups (p >0.05). 24-hour urine oxalate, sodium and magnesium values and 24-hour urine volume did not differ significantly between the groups (p> 0.05). 24-hour urine protein value was significantly higher in ADPKD+LIT and ADPKD groups than in the CALCULI and HEALTHY groups (p <0.05). 24-hour urine protein value did not differ significantly between CALCULI and HEALTHY groups (p >0.05). 24-hour urine protein value did not differ significantly between ADPKD+LIT and ADPKD groups (p >0.05). ADPKD+LIT, ADPKD and CALCULI groups Urine pH (spot urine) value was significantly lower than in the HEALTHY group (p <0.05). Urine pH value did not differ significantly between ADPKD+LIT, ADPKD and CALCULI groups (p >0.05). Serum parathormone (PTH) value was significantly higher in ADPKD+LIT and ADPKD groups than in the HEALTHY group (p <0.05). PTH values did not differ significantly between the CALCULI and HEALTHY groups (p> 0.05). PTH values did not differ significantly between ADPKD+LIT, ADPKD and CALCULI groups (p> 0.05). There was no significant difference between the groups in terms of serum ferritin, sodium, potassium, calcium, phosphorus, magnesium and uric acid (p> 0.05). There was no significant difference in total kidney volumes between ADPKD+LIT and ADPKD groups (total kidney volumes for the two groups, respectively; 1138.9 ± 1253.7 ml ve 1086.3 ± 1283.3 ml; p=0.794) Conclusion: In our study, 24-hour urine citrate level was found to be significantly lower in ADPKD+LIT and ADPKD patients compared to the volunteers in the CALCULI and HEALTHY groups (p <0.05). There was no significant difference in 24-hour urine citrate level between ADPKD + LIT and ADPKD groups (p> 0.05). Low 24-hour urine citrate values is a predisposing factors for urinary system stone formation in autosomal dominant polycystic kidney disease patients. Keywords: Autosomal dominant polycystic kidney disease, nephrolithiasis, urinary system stone, kidney stone, 24 hour urine calcium, 24 hour urine urat, 24 hour urine oxalate, 24 hour urine citrate, hypocitraturia.