Revisiting racial differences in ESRD due to ADPKD in the United States

Erin L Murphy,Madeline L Droher,Katrina Lehmann Blount,Feng Dai,Lauren Liberti,Deidra C Crews,Neera K Dahl

doi:10.1186/s12882-019-1241-1

Erin L Murphy, Madeline L Droher + Show 5 more

Open Access

https://doi.org/10.1186/s12882-019-1241-1

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Abstract

IntroductionAutosomal dominant polycystic kidney disease (ADPKD) affects all races. Whether the progression of ADPKD varies by race remains unclear.MethodsIn this retrospective cohort study from 2004 to 2013 non-Hispanic blacks and non-Hispanic whites of all ages classified in the US Renal Data System (USRDS) with incident ESRD from ADPKD (n = 23,647), hypertension/large vessel disease (n = 296,352), or diabetes mellitus (n = 451,760) were stratified into five-year age categories ranging from < 40 to > 75 (e.g., < 40, 40–44, 45–49, …, 75+). The Cochran-Mantel-Haenszel test was used to determine the association of race and incidence of ESRD from ADPKD, diabetes, or hypertension. The difference in the proportions of ESRD in non-Hispanic black and non-Hispanic white patients at each age categorical bin was compared by two-sample proportion test. The age of ESRD onset between non-Hispanic black and non-Hispanic white patients at each year was compared using two-sample t-test with unequal variance.Results1.068% of non-Hispanic blacks and 2.778% of non-Hispanic whites had ESRD attributed to ADPKD. Non-Hispanic blacks were less likely than non-Hispanic whites to have ESRD attributed to ADPKD (odds ratio (OR) (95% CI) = 0.38 (0.36–0.39), p < 0.0001). Using US Census data as the denominator to adjust for population differences non-Hispanic blacks were still slightly under-represented (OR (95% CI) 0.94 (0.91–0.96), p = 0.004). However, non-Hispanic blacks with ADPKD had a younger age of ESRD (54.4 years ±13) than non-Hispanic whites (55.9 years ±12.8) (p < 0.0001). For those < 40 years old, more non-Hispanic blacks had incident ESRD from ADPKD than non-Hispanic whites (9.49% vs. 7.68%, difference (95% CI) = 1.81% (0.87–2.84%), p < 0.001) for the combined years examined.ConclusionsAs previously shown, we find the incidence of ESRD from ADPKD in non-Hispanic blacks is lower than in non-Hispanic whites. Among the younger ADPKD population (age < 40), however, more non-Hispanic blacks initiated dialysis than non-Hispanic whites. Non-Hispanic blacks with ADPKD initiated dialysis younger than non-Hispanic whites. A potential implication of these findings may be that black race should be considered an additional risk factor for progression in ADPKD.

Highlights

Autosomal dominant polycystic kidney disease (ADPKD) affects all races
We looked at proportions of non-Hispanic blacks and non-Hispanic whites with incident end-stage renal disease (ESRD) secondary to ADPKD, HTN or diabetes in the US Renal Data System (USRDS) database
For the combined years examined (2004 through 2013), there were a total of 771,759 non-Hispanic whites and non-Hispanic blacks with incident ESRD with primary disease diagnoses of ADPKD (n = 23,647), diabetes (n = 451,760), or hypertension (n = 296,352) (Fig. 1)

Summary

Introduction

Autosomal dominant polycystic kidney disease (ADPKD) affects all races. Whether the progression of ADPKD varies by race remains unclear. In each arm of HALT-PKD (study A, standard – patients with higher eGFRs and standard blood pressure targets, study A, low – patients with higher eGFRs and low blood pressure targets, and study B – patients with lower eGFRs), there are fewer black ADPKD patients than would be expected relative to general US population (2.5, 2.6, and 2.5%, respectively) [5]. Both HALT and CRISP may underestimate a potential impact of race on progression of ADPKD because of low numbers of blacks in the studies

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