Real-world epidemiology and renal outcomes of ADPKD in Türkiye: the PKD-TURK cohort.

Abstract

Introduction: Real-world epidemiological and longitudinal outcome data on autosomal dominant polycystic kidney disease (ADPKD) remain limited in underrepresented populations, including Türkiye. We aimed to characterize the epidemiology, regional distribution, and renal outcomes of ADPKD in a large multicenter national cohort.

Methods: In this retrospective multicenter study, adult patients with ADPKD were identified across tertiary nephrology centers in six regions of Türkiye (2010-2025). Study-based prevalence was calculated using Turkish Statistical Institute population data. Longitudinal renal outcomes were evaluated using serial eGFR measurements and Cox regression models identified predictors of ≥ 40% eGFR decline.

Results: A total of 2361 patients were included (mean age 38.6 ± 14 years; 51.8% female). Median province-level study-based prevalence was 3.86 per 100,000 population (IQR 2.92-5.49), with substantial regional variation, highest in the Black Sea region (13.46 per 100,000). Study-based prevalence increased significantly over time (annual percent change 14.4%; 95% CI 13.1-15.6; p < 0.001). During a median follow-up of 6 years, 23.9% experienced a ≥ 40% eGFR decline and 10.5% progressed to kidney failure (eGFR < 15 ml/min/1.73m2). Median annual eGFR decline was - 3.33 mL/min/1.73 m²/year. In multivariable analysis, age (adjusted HR 1.02; 95% CI 1.00-1.03; p = 0.010) and hypertension (adjusted HR 2.33; 95% CI 1.25-4.32; p = 0.007) were independently associated with renal progression, whereas tolvaptan use was associated with a lower risk of progression (adjusted HR 0.56; 95% CI 0.37-0.85; p = 0.004). The Mayo Imaging Classification remained independently predictive of renal outcomes (p = 0.027).

Conclusions: This large real-world multicenter cohort highlights the geographically heterogeneous study-based burden of ADPKD across participating regions of Türkiye. Increasing prevalence over time likely reflects improved disease recognition, whereas the relatively low study-based prevalence suggests persistent under-recognition of ADPKD. These findings provide important longitudinal outcome data from an underrepresented population and support the need for earlier detection and improved risk stratification in ADPKD.