More on the invisibility of chronic kidney disease… and counting

Abstract

Lack of awareness of a diagnosis of chronic kidney disease (CKD) in patients and physicians is a major contributor to fueling the CKD pandemic by also making it invisible to researchers and health authorities. This is an urgent matter to tackle if dire predictions of future CKD burden are to be addressed. CKD is set to become the fifth-leading global cause of death by 2040 and the second-leading cause of death before the end of the century in some countries with long life expectancy. Coronavirus disease 2019 (COVID-19) illustrated this invisibility: only after the summer of 2020 did it become clear that CKD was a major driver of COVID-19 mortality, both in terms of prevalence as a risk factor and of the risk conferred for lethal COVID-19. However, by that time the damage was done: news outlets and scientific publications continued to list diabetes and hypertension, but not CKD, as major risk factors for severe COVID-19. In a shocking recent example from Sweden, CKD was found to be diagnosed in just 23% of 57 880 persons who fulfilled diagnostic criteria for CKD. In the very same large cohort, diabetes or cancer were diagnosed in 29% of persons, hypertension in 82%, cardiovascular disease in 39% and heart failure in 28%. Thus, from the point of view of physicians, patients and health authorities, CKD was the least common comorbidity in persons with CKD, ranking sixth, after other better-known conditions. One of the consequences of this lack of awareness was that nephrotoxic medications were more commonly prescribed in patients with CKD who did not have a diagnosis of CKD. Low awareness of CKD may also fuel concepts such as the high prevalence of hypertensive nephropathy when CKD is diagnosed after the better-known condition of hypertension.

Keywords: awareness; chronic kidney disease; hypertensive nephropathy; misdiagnosis; nephrotoxic drugs; nephrotoxicity.

Figure 1:

Comorbidities diagnosed in a Swedish cohort of patients with CKD, representing clinical conditions that treating physicians were aware of. Inclusion in the cohort required a researcher diagnosis of CKD based on the presence of two eGFR values <60 mL/min/1.73 m² separated by at least 90 days, as per the Kidney Disease: Improving Global Outcomes definition. Patients on KRT were excluded. Note that among persons included in the cohort because researchers retrospectively diagnosed CKD, the physician in charge diagnosed cancer or diabetes more commonly than CKD.

Figure 2:

Need to monitor the prescription of potentially nephrotoxic drugs to persons with CKD. The impact of monitoring clinical practice regarding the prescription of clearly nephrotoxic or potentially nephrotoxic drugs to persons with CKD requires awareness of the CKD diagnosis and may impact both individual patient care as well as the global care for persons with CKD.

Figure 3:

Prescription of potentially nephrotoxic drugs in Swedish and US cohorts of persons with CKD. Data expressed as a percentage of persons prescribed a potentially nephrotoxic drug among the whole cohort of persons with CKD.

Figure 4.

Integration of knowledge regarding preclinical evidence of cytotoxicity of PPIs with epidemiological data linking PPIs to kidney injury.