OVERTURE: A Worldwide, Prospective, Observational Study of Disease Characteristics in Patients With ADPKD

Introduction: The course of autosomal dominant polycystic kidney disease (ADPKD) varies greatly among affected individuals, necessitating natural history studies to characterize the determinants and effects of disease progression. Therefore, we conducted an observational, longitudinal study (OVERTURE; NCT01430494) of patients with ADPKD. Methods: This prospective study enrolled a large international population (N = 3409) encompassing a broad spectrum of ages (12–78 years), chronic kidney disease (CKD) stages (G1–G5), and Mayo imaging classifications (1A–1E). Outcomes included kidney function, complications, quality of life, health care resource utilization, and work productivity. Results: Most subjects (84.4%) completed ≥12 months of follow-up. Consistent with earlier findings, each additional l/m of height-adjusted total kidney volume (htTKV) on magnetic resonance imaging (MRI) was associated with worse outcomes, including lower estimated glomerular filtration rate (eGFR) (regression coefficient 17.02, 95% confidence interval [CI] 15.94–18.11) and greater likelihood of hypertension (odds ratio [OR] 1.25, 95% CI 1.17–1.34), kidney pain (OR 1.22, 95% CI 1.11–1.33), and hematuria (OR 1.35, 95% CI 1.21–1.51). Greater baseline htTKV was also associated with worse patient-reported health-related quality of life (e.g., ADPKD Impact Scale physical score, regression coefficient 1.02, 95% CI 0.65–1.39), decreased work productivity (e.g., work days missed, regression coefficient 0.55, 95% CI 0.18–0.92), and increased health care resource utilization (e.g., hospitalizations, OR 1.48, 95% CI 1.33–1.64) during follow-up. Conclusion: Although limited by a maximum 3-year duration of follow-up, this observational study characterized the burden of ADPKD in a broad population and indicated the predictive value of kidney volume for outcomes other than kidney function.