Mortality risk in patients with autosomal dominant polycystic kidney disease

Abstract

Background: Autosomal dominant polycystic kidney disease (ADPKD) is the leading inheritable cause of end-stage renal disease (ESRD). Mortality data specific to patients with ADPKD is currently lacking; thus, the aim of this study was to estimate mortality in patients with ADPKD.

Methods: We analyzed data from the United States Renal Data System (USRDS) for patients with ADPKD available during the study period of 01/01/2014-12/31/2016, which included a cohort of patients with non-ESRD chronic kidney disease (CKD) and a cohort of patients with ESRD. Mortality rates with 95% confidence intervals (CIs) were calculated overall and by age group, sex, and race for the full dataset and for a subset of patients aged ≥ 65 years. Adjusted mortality hazard ratios (HRs) were calculated using Cox regression modeling by age group, sex, race, and CKD stage (i.e., non-ESRD CKD stages 1-5) or ESRD treatment (i.e., dialysis and transplant).

Results: A total of 1,936 patients with ADPKD and non-ESRD CKD and 37,461 patients with ADPKD and ESRD were included in the analysis. Age-adjusted mortality was 18.4 deaths per 1,000 patient-years in the non-ESRD CKD cohort and 37.4 deaths per 1,000 patient-years in the ESRD cohort. As expected, among the non-ESRD CKD cohort, patients in CKD stages 4 and 5 had a higher risk of death than patients in stage 3 (HR = 1.59 for stage 4 and HR = 2.71 for stage 5). Among the ESRD cohort, patients receiving dialysis were more likely to experience death than patients who received transplant (HR = 2.36). Age-adjusted mortality among patients aged ≥ 65 years in the non-ESRD CKD cohort was highest for Black patients (82.7 deaths per 1,000 patient-years), whereas age-adjusted mortality among patients aged ≥ 65 years in the ESRD cohort was highest for White patients (136.1 deaths per 1,000 patient-years).

Conclusions: Mortality rates specific to patients aged ≥ 65 years suggest racial differences in mortality among these patients in both non-ESRD CKD and ESRD cohorts. These data fill an important knowledge gap in mortality estimates for patients with ADPKD in the United States.

Keywords: Autosomal dominant polycystic kidney disease; End-stage renal disease; Mortality.

Fig. 1

Selection of patients for the ADPKD Non-ESRD CKD and ESRD Cohorts ADR = Annual Data Report; ADPKD = autosomal dominant polycystic kidney disease; CKD = chronic kidney disease; ESRD = end-stage renal disease; USRDS = United States Renal Data System. Note: USRDS provided a flag variable in the ESRD database to indicate a data issue and stated that they did not include these records in the ADR; therefore, the current analysis also excluded these records. As shown in the figure, this resulted in 144 patients being excluded from the ESRD study cohort

Fig. 2

Mortality among patients with ADPKD overall, by sex, and by race ADPKD = autosomal dominant polycystic kidney disease; ESRD = end-stage renal disease. Note: In addition to “White,” “Black,” “Hispanic,” and “Asian” in the non-ESRD CKD USRDS dataset, “race” also included “Native American,” “Other,” and “Unknown,” which have been grouped in this figure as “Other or unknown.” In addition to “White,” “Black/African American” (referred to as “Black” in this figure), “Hispanic,” and “Asian” in the ESRD USRDS dataset, “race” also included “American Indian or Alaska Native,” “Native Hawaiian or Pacific Islander,” “Other or Multiracial,” and “Unknown,” which have been grouped in this figure as “Other or unknown.”

Fig. 3

Mortality among patients with ADPKD aged ≥ 65 years overall, by sex, and by race ADPKD = autosomal dominant polycystic kidney disease; ESRD = end-stage renal disease. Note: In addition to “White,” “Black,” “Hispanic,” and “Asian” in the non-ESRD CKD USRDS dataset, “race” also included “Native American,” “Other,” and “Unknown,” which have been grouped in this figure as “Other or unknown.” In addition to “White,” “Black/African American” (referred to as “Black” in this figure), “Hispanic,” and “Asian” in the ESRD USRDS dataset, “race” also included “American Indian or Alaska Native,” “Native Hawaiian or Pacific Islander,” “Other or Multiracial,” and “Unknown,” which have been grouped in this figure as “Other or unknown.”