Objective:To evaluate the impact of roxadustat on thyroid function and to identify the associated factors in patients undergoing maintenance peritoneal dialysis (PD).Methods:This study was a single-center retrospective study. PD patients who received roxadustat or recombinant human erythropoietin (rHuEPO) treatment at Nanjing Drum Tower Hospital between January 2020 and June 2024 were included. The general and clinical information as well as laboratory indexes were collected. Serum free triiodothyronine (FT3), free thyroxine (FT4) and thyroid-stimulating hormone (TSH) were compared before and after treatment initiation. Hemoglobin (Hb) responses were also observed between the two groups. Logistic regression analysis was performed to explore the factors associated with thyroid function changes.Results:A total of 120 patients were enrolled, with an age of (55.17±16.42) years, including 66 males (55.0%). There were 81 patients received roxadustat (roxadustat group) and 39 patiens received rHuEPO (rHuEPO group). Compared to the rHuEPO group, the roxadustat group had a higher proportion of patients with diabetes ( χ 2= 4.172, P=0.041), a shorter PD vintage ( Z=-3.406, P=0.002), a lower serum level of total cholesterol ( Z=-2.082, P=0.037) and a lower level of fasting blood glucose ( Z=-2.589, P=0.010). Following treatment with roxadustat, the levels of FT4 ( Z=-5.349, P<0.01) and TSH ( Z=-3.720, P<0.01) decreased significantly. In contrast, no significant changes in FT4 or TSH levels were observed in the rHuEPO group (both P>0.05). For both roxadustat and rHuEPO groups, there were no significant changes in FT3 levels after treatment (both P>0.05). Multivariate analysis identified that higher baseline TSH (TSH≥2.27 μIU/ml, OR=1.581, 95% CI 1.196-2.089, P=0.001) and roxadustat exposure ( OR=3.432, 95% CI 1.410-8.355, P=0.007) as independent associated factors of subsequent TSH decline, and identified that higher baseline FT4 (FT4≥14.9 pmol/L, OR=1.390, 95% CI 1.162-1.662, P=0.001) and roxadustat exposure ( OR=5.798, 95% CI 2.225-15.113, P=0.001) as independent associated factors of subsequent FT4 decline. The degrees of hemoglobin changes after roxadustat or rHuEPO treatment did not differ significantly between roxadustat group and rHuEPO group ( t=-1.062, P=0.290). Of the 31 patients who underwent a second thyroid function test during roxadustat treatment, 24 continued with the original regimen, while 7 discontinued roxadustat. Among 24 patients who maintained roxadustat treatment, TSH ( Z=-0.400, P=0.689) and FT4 ( t=0.143, P=0.888) remained stable between the second and third tests. All 7 patients who discontinued roxadustat treatment showed TSH rebound and the changes of TSH levels were more significant than that in continuers ( Z=-2.505, P=0.012). FT4 recovery occurred in only 3 of them, with no significant difference in FT4 change between discontinuers and continuers ( Z=-0.685, P=0.493). Conclusions:Roxadustat commonly suppresses TSH and FT4, but not FT3, in PD patients. Baseline levels of TSH and FT4 are key associated factors of the inhibitory effect of roxadustat on thyroid function. This suppression does not intensify with prolonged exposure and is reversible after discontinuation, with TSH levels normalizing more quickly than FT4. Roxadustat-induced thyroid suppression does not compromise its efficacy in treating renal anemia.

Objective:To evaluate the impact of roxadustat on thyroid function and to identify the associated factors in patients undergoing maintenance peritoneal dialysis (PD).Methods:This study was a single-center retrospective study. PD patients who received roxadustat or recombinant human erythropoietin (rHuEPO) treatment at Nanjing Drum Tower Hospital between January 2020 and June 2024 were included. The general and clinical information as well as laboratory indexes were collected. Serum free triiodothyronine (FT3), free thyroxine (FT4) and thyroid-stimulating hormone (TSH) were compared before and after treatment initiation. Hemoglobin (Hb) responses were also observed between the two groups. Logistic regression analysis was performed to explore the factors associated with thyroid function changes.Results:A total of 120 patients were enrolled, with an age of (55.17±16.42) years, including 66 males (55.0%). There were 81 patients received roxadustat (roxadustat group) and 39 patiens received rHuEPO (rHuEPO group). Compared to the rHuEPO group, the roxadustat group had a higher proportion of patients with diabetes ( χ 2= 4.172, P=0.041), a shorter PD vintage ( Z=-3.406, P=0.002), a lower serum level of total cholesterol ( Z=-2.082, P=0.037) and a lower level of fasting blood glucose ( Z=-2.589, P=0.010). Following treatment with roxadustat, the levels of FT4 ( Z=-5.349, P<0.01) and TSH ( Z=-3.720, P<0.01) decreased significantly. In contrast, no significant changes in FT4 or TSH levels were observed in the rHuEPO group (both P>0.05). For both roxadustat and rHuEPO groups, there were no significant changes in FT3 levels after treatment (both P>0.05). Multivariate analysis identified that higher baseline TSH (TSH≥2.27 μIU/ml, OR=1.581, 95% CI 1.196-2.089, P=0.001) and roxadustat exposure ( OR=3.432, 95% CI 1.410-8.355, P=0.007) as independent associated factors of subsequent TSH decline, and identified that higher baseline FT4 (FT4≥14.9 pmol/L, OR=1.390, 95% CI 1.162-1.662, P=0.001) and roxadustat exposure ( OR=5.798, 95% CI 2.225-15.113, P=0.001) as independent associated factors of subsequent FT4 decline. The degrees of hemoglobin changes after roxadustat or rHuEPO treatment did not differ significantly between roxadustat group and rHuEPO group ( t=-1.062, P=0.290). Of the 31 patients who underwent a second thyroid function test during roxadustat treatment, 24 continued with the original regimen, while 7 discontinued roxadustat. Among 24 patients who maintained roxadustat treatment, TSH ( Z=-0.400, P=0.689) and FT4 ( t=0.143, P=0.888) remained stable between the second and third tests. All 7 patients who discontinued roxadustat treatment showed TSH rebound and the changes of TSH levels were more significant than that in continuers ( Z=-2.505, P=0.012). FT4 recovery occurred in only 3 of them, with no significant difference in FT4 change between discontinuers and continuers ( Z=-0.685, P=0.493). Conclusions:Roxadustat commonly suppresses TSH and FT4, but not FT3, in PD patients. Baseline levels of TSH and FT4 are key associated factors of the inhibitory effect of roxadustat on thyroid function. This suppression does not intensify with prolonged exposure and is reversible after discontinuation, with TSH levels normalizing more quickly than FT4. Roxadustat-induced thyroid suppression does not compromise its efficacy in treating renal anemia.