Association of Kidney Volume With Patient-Reported Outcomes in ADPKD

Autosomal dominant polycystic kidney disease (ADPKD) may impose physical and emotional burdens, partly through enlarged kidneys. The association of health-related quality-of-life (HRQOL) with total kidney volume (TKV) remains unclear, particularly in combination with kidney function and pain status.

Participants diagnosed with ADPKD were recruited between 2017 and 2023. We examined the associations of TKV, estimated glomerular filtration rate using the Chronic Kidney Disease Epidemiology Collaboration race-free creatinine equation (eGFR), and chronic kidney pain (Yes/No) with HRQOL (Short Form-36 [SF-36] scores) using multivariable linear regression. Factor analysis of mixed data (FAMD) was used to classify patients into clusters based on TKV, eGFR, and kidney pain; and their HRQOL was compared.

Of 456 participants, mean (SD) age was 47 (16) years, 216 (47%) were males, eGFR was 81 (27) ml/min per 1.73 m², and median (interquartile range) TKV was 922 (532-1547) ml. Mean (95% confidence interval [CI]) SF-36) physical component summary (PCS) scores were 53 (52-55), 51 (50-53), and 51 (50-53) across increasing TKV tertiles (P = 0.02), respectively, even after adjusting for kidney pain and function. Mental component summary (MCS) scores were similar across tertiles. Lower eGFR and kidney pain were associated with worse HRQOL. We identified 4 clusters as follows: (i) low or moderate ADPKD severity, no pain; (ii) low or moderate ADPKD severity, kidney pain; (iii) high ADPKD severity, no pain; (iv) high ADPKD severity, kidney pain. Ranked from best to most impaired: PCS, 1 > 2 = 3 > 4; MCS, 1 = 3 > 2 = 4. Mediation analysis showed an indirect association between TKV and MCS through kidney pain.

TKV is associated with physical health, independent of kidney pain and function, and with mental health (MH) indirectly through kidney pain. Alleviating kidney pain, preserving function, and limiting kidney enlargement in ADPKD may all help to improve HRQOL.