Nephrology
Mediation Analysis of Urine Osmolality and Response to Tolvaptan in Autosomal Dominant Polycystic Kidney Disease: A Post Hoc Assessment
By Matsuura R, Doi K, Zhang Z and 3 others.
Abstract
Aim
Tolvaptan delays growth in total kidney volume (TKV) and decline in estimated glomerular filtration rate (eGFR) among individuals with autosomal dominant polycystic kidney disease (ADPKD) at elevated risk of rapid progression. We evaluated changes in urine osmolality (Uosm) after treatment initiation as a potential biomarker of long-term response.
Methods
This was a post hoc analysis of TEMPO 3:4, a 3-year, randomized, placebo-controlled trial of tolvaptan. Causal mediation analysis assessed if the effect of tolvaptan on longer-term outcomes of change in eGFR and TKV at month 36 was mediated by change in Uosm at week 3. Analyses were performed separately for non-Japanese and Japanese participants.