Association of anemia with long-term renal prognosis in autosomal dominant polycystic kidney disease using time-series analysis

We enrolled 553 patients with autosomal dominant polycystic kidney disease (ADPKD) to investigate the association between hemoglobin (Hb) levels and kidney outcomes. Renal outcome was defined as a 50% reduction in estimated glomerular filtration rate or the initiation of renal replacement therapy. Survival analyses and logistic regression were used to generate time-series McFadden’s pseudo-R-squared (pseudo-R²) values as a goodness-of-fit index to compare the relative contribution of Hb cut-offs over follow-up time, and the mean pseudo-R² values from the first to the 17th year (1–17Y mean) were calculated to summarize long-term patterns. Multivariable Cox analyses indicated that lower Hb was independently associated with kidney disease progression (per 1 g/dL decrease in Hb, P = 0.0016). The highest 1–17Y mean values were observed for Hb < 12.0 g/dL for the entire cohort (1–17Y mean: 0.1128), Hb < 13 g/dL for men (1–17Y mean: 0.1838), and Hb < 12 g/dL for women (1–17Y mean: 0.1191). These findings suggest that Hb thresholds around 12.0 g/dL overall—and sex-specific thresholds of 13 g/dL in men and 12 g/dL in women—showed relatively stronger and more persistent associations with renal outcomes over follow-up time.