Does wealth make health? Cherchez la renal replacement therapy

Burden, access and disparities in kidney disease: chronic kidney disease hotspots and progress one step at a time

The 2019 International Society of Nephrology World Kidney Day theme is Kidney Health for Everyone Everywhere. It focuses on the uneven burden of acute kidney injury and chronic kidney disease (CKD) in different communities, identifies disparities and challenges in access to care and calls for universal health coverage for prevention and early treatment of kidney disease. This topic is fully in line with the Clinical Kidney Journal (ckj) editorial strategy for improving worldwide kidney care without leaving any community behind. Indeed, the first PubMed-recorded use of the term CKD hotspot was in ckj, where it was defined as 'countries, region[s], communities or ethnicities with higher than average incidence of CKD'. This issue of ckj contains the World Kidney Day editorial as well as contributions that illustrate two concepts: the need to validate biochemical thresholds generated in developed countries in other populations, as exemplified by Kidney Disease: Improving Global Outcomes CKD-mineral and bone disorder parameters in an African population, and the fact that some disease associations characteristic of developing countries may be described initially in developed countries, as exemplified by the association of APOL1 variants with CKD or by minimal change disease secondary to malaria, but have to be validated locally.

Is the Rise in the Prevalence of Renal Replacement Therapy at Older Ages the Price for Living Longer?

Background

Renal replacement therapy (RRT) is one of the most expensive in renal medicine. Cross-sectional studies suggest that life expectancy increases in the general population are associated with a higher burden of RRT. This study tests this hypothesis in a prospective setting among people aged 75+ living in Western Europe.

Methods

We gathered sex-specific data for 11 Western European countries in 2005-2014. RRT prevalence on country level was extracted from the ERA-EDTA registry, while data on population size and life expectancy for the 75+ age group came from the Eurostat database. GDP per capita was extracted from the OECD database. To measure the association between RRT prevalence and life expectancy, we performed Poisson regression models separately for each country and for all countries combined. To adjust for confounding, GDP per capita as well as time and country-fixed effects were included.

Results

Our analysis revealed that living longer coincides with rising RRT prevalence at ages 75+ in Western Europe between 2005 and 2014. On average, a 1-year increase in life expectancy was associated with a roughly 20% increase in RRT prevalence [(95% CI) 21-23% in men and 19-22% in women]. However, after adjustments for confounding were made, the association became insignificant among women and became weaker among men, falling to a level of 11% [(95% CI) 6-17%].

Conclusion

Living longer was not necessarily associated with a higher burden of RRT in Western European countries.

Translational science in chronic kidney disease

The KDIGO definition of chronic kidney disease (CKD) allowed a more detailed characterization of CKD causes, epidemiology and consequences. The picture that has emerged is worrisome from the point of view of translation. CKD was among the fastest growing causes of death in the past 20 years in age-adjusted terms. The gap between recent advances and the growing worldwide mortality appears to result from sequential roadblocks that limit the flow from basic research to clinical development (translational research type 1, T1), from clinical development to clinical practice (translational research T2) and result in deficient widespread worldwide implementation of already available medical advances (translational research T3). We now review recent advances and novel concepts that have the potential to change the practice of nephrology in order to improve the outcomes of the maximal number of individuals in the shortest possible interval. These include: (i) updating the CKD concept, shifting the emphasis to the identification, risk stratification and care of early CKD and redefining the concept of aging-associated 'physiological' decline of renal function; (ii) advances in the characterization of aetiological factors, including challenging the concept of hypertensive nephropathy, the better definition of the genetic contribution to CKD progression, assessing the role of the liquid biopsy in aetiological diagnosis and characterizing the role of drugs that may be applied to the earliest stages of injury, such as SGLT2 inhibitors in diabetic kidney disease (DKD); (iii) embracing the complexity of CKD as a network disease and (iv) exploring ways to optimize implementation of existing knowledge.