Burden of Chronic Kidney Disease by KDIGO Categories of Glomerular Filtration Rate and Albuminuria: A Systematic Review

Abstract

Introduction: The Kidney Disease: Improving Global Outcomes (KDIGO) 2012 guidelines recommend classifying patients by glomerular filtration rate (GFR) and albuminuria to predict chronic kidney disease (CKD) prognosis. The aim of this systematic review was to explore the epidemiological burden of CKD stratified by the KDIGO 2012 categories.

Methods: MEDLINE® and Embase were searched for observational studies of patients with CKD with results stratified according to the KDIGO 2012 classification. Investigated outcomes were prevalence, incidence, and risk factors and complications of CKD, including mortality.

Results: The review included ten observational studies with 3033 to 46,949 participants, conducted in the USA, China, France, Italy and Spain. The most frequently reported outcome was the prevalence of CKD (GFR categories G3-5), ranging from 2% to 17%. Most participants were normoalbuminuric, with 0.4-3.2% macroalbuminuric, and most fell within the KDIGO 2012 low-risk or moderate-risk groups, with 0.9-5.6% in the high-risk and 0.3-4.8% in the very high-risk groups. Although scarce, data on the prevalence of comorbidities in CKD according to the KDIGO classification suggest that they increase with albuminuria severity.

Conclusions: Patients with CKD frequently have complications, but only a small proportion have severely increased albuminuria or fall within the KDIGO high-risk or very high-risk groups. These groups, however, are associated with the highest burden of disease, as comorbidities are more prevalent with increasing albuminuria severity. New studies framed by the KDIGO 2012 classification are needed to address key gaps in the understanding of CKD burden and outcomes.

Keywords: Albuminuria; CKD; Cardiovascular diseases; Chronic kidney disease; Diabetes mellitus; Hypertension; KDIGO; Prevalence; Renal insufficiency.

Fig. 1

Prognosis of CKD by GFR and albuminuria categories. Green, low risk of disease progression; yellow, moderately increased risk of disease progression; orange, high risk of disease progression; red, very high risk of disease progression. CKD chronic kidney disease, GFR glomerular filtration rate, ACR albumin-to-creatinine ratio

Fig. 2

PRISMA flowchart of records included and excluded in the review. Expert advice: one article was identified on the basis of advice from KT and RPF. PRISMA preferred reporting items for systematic reviews and meta-analyses, SR systematic review

Fig. 3

Prevalence of each KDIGO 2012 category in general population samples. Tables informed by seven studies (total combined), five studies (USA), one study (Italy), two studies (China). Note that the number of studies does not add up to seven as one study reported data for both USA and China. Numbers represent percentage of entire sample. Totals for each row and column are not presented as the highest prevalence in one category may not come from the same study as the highest prevalence in another category, which would misleadingly lead to a summation of values across categories to result in a range where the upper value appears to be > 100%. Green, low risk of disease progression; yellow, moderately increased risk of disease progression; orange, high risk of disease progression; red, very high risk of disease progression. ACR albumin-to-creatinine ratio, GFR glomerular filtration rate, KDIGO Kidney Disease: Improving Global Outcomes

Fig. 4

Prevalence of each KDIGO 2012 category in a cohort of patients with CKD. Data from Stengel 2019 [23]. ^aPatients considered to be at high risk of CKD progression by the KDIGO 2012 guidelines, but very high risk by Stengel 2019 [23]. Numbers represent percentage of entire sample. Green, low risk of disease progression; yellow, moderately increased risk of disease progression; orange, high risk of disease progression; red, very high risk of disease progression; grey, patients without ACR data. ACR albumin-to-creatinine ratio, CKD chronic kidney disease, GFR glomerular filtration rate, KDIGO Kidney Disease: Improving Global Outcomes