Association of 24-hour urinary parameters with renal function and other comorbidities in autosomal dominant polycystic kidney disease

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is a leading hereditary cause of chronic kidney disease (CKD) and end-stage kidney disease (ESKD). While several clinical and genetic predictors of disease progression have been identified, the significance of urinary metabolic profile in ADPKD remains insufficiently explored. This study aimed to evaluate the association between 24-hour urinary parameters, renal function, and clinically relevant comorbidities in patients with ADPKD, and to explore whether these urinary alterations are specific to ADPKD or associated with declining kidney function. METHODS: In this retrospective study, 42 adult patients with ADPKD were analyzed. Patients were stratified according to estimated glomerular filtration rate (eGFR) (< 60 vs. ≥60 mL/min/1.73 m²). Clinical characteristics, comorbidities, and laboratory data were obtained from medical records. 24-hour urinary excretion of calcium, citrate, uric acid, and protein was assessed. Comparative analyses and logistic regression models were used to evaluate associations between urinary parameters and renal insufficiency. RESULTS: Hypertension (76.2%) and hepatic cysts (71.4%) were the most common clinical findings. Patients with eGFR < 60 mL/min/1.73 m² showed significantly lower 24-hour urinary excretion of calcium (44 vs. 94.5 mg/day), uric acid (307 vs. 492.3 mg/day), and citrate (110 vs. 550 mg/day) (all p < 0.05). Logistic regression analysis demonstrated that reduced urinary calcium and uric acid excretion were associated with renal insufficiency, while low citrate excretion was linked to nephrolithiasis history. CONCLUSIONS: Reduced urinary excretion of calcium and uric acid is significantly associated with impaired renal function in ADPKD. These findings parallel the metabolic alterations observed in general CKD populations, suggesting that the decline in urinary parameters is likely driven by renal function loss. Monitoring 24-hour urinary metabolic profiles may provide adjunctive clinical insights for the management of ADPKD. Prospective studies are needed to clarify their prognostic value in early disease stages.