Individualized Risk of CKD Progression among US Adults

Abstract

Key Points:

1. A total of 8.42 million US adults have high CKD progression risk, and 4.77 million of them have eGFR >60 ml/min per 1.73 m².

2. An individual's absolute risk of CKD progression is important in the diagnosis and prognostication of CKD.

Background: CKD is currently defined using GFR or albuminuria. This is on the basis of the relative risk of mortality and kidney outcomes compared with a healthy population and does not consider an individual's absolute risk of CKD progression.

Methods: Using National Health and Nutrition Examination Survey data from 1999 to 2020, we characterized the individual-level absolute 3-year risk of ≥40% decline in eGFR (ml/min per 1.73 m²) or kidney failure (3-year risk) among US adults. We categorized the 3-year risk and considered ≥5% as high risk.

Results: Among 199.81 million US adults, 8.42 million (4%) had a 3-year risk ≥5%, including 1.04 million adults without CKD (eGFR ≥60 and albuminuria <30 mg/g). These high-risk adults without CKD as currently defined had risk factors including hypertension (98%), heart failure (72%), and diabetes (44%). A total of 15.51 million adults had CKD with preserved eGFR (eGFR ≥60 and albuminuria ≥30 mg/g)—3.73 million had a 3-year risk ≥5%, 41% of whom did not have diabetes and thus would not be screened for albuminuria using current screening recommendations. The 3-year risk of CKD progression was low (risk <5%) in 94% of the 5.66 million US adults with CKD stage G3a-A1 (eGFR 45 to <60 and albuminuria <30 mg/g).

Conclusions: Assessment of the individual's absolute risk of CKD progression allowed further risk stratification of patients with CKD and identified individuals without CKD, as currently defined, who were at high risk of CKD progression.

Podcast: This article contains a podcast at https://dts.podtrac.com/redirect.mp3/www.asn-online.org/media/podcast/JASN/2024_06_18_ASN0000000000000377.mp3

Graphical abstract

Figure 1

Distribution of 3-year risk of CKD progression across eGFR and albuminuria categories among US adults with preserved and reduced eGFR. (A) US adults with preserved eGFR (eGFR ≥60 ml/min per 1.73 m²): 173.95 million US adults did not have CKD on the basis of current laboratory criteria, and 1.04 million of them had 3-year risk ≥5%. 15.51 million US adults had CKD on the basis of albuminuria alone (UACR ≥30 mg/g and eGFR ≥60 ml/min per 1.73 m²); 24% of them had a 3-year risk of CKD progression ≥5%. (B) US adults with reduced eGFR (eGFR <60 ml/min per 1.73 m²): 10.35 million US adults had CKD on the basis of reduced eGFR (eGFR <60 ml/min per 1.73 m²) regardless of albuminuria; 55% of them (5.66 million) belonged to CKD stage G3a-A1. 6.71 million US adults with CKD with reduced eGFR (65%) had a 3-year risk <5%. Most of them are in CKD stage 3A1. Height of each bar represents the total number of participants per eGFR and UACR category. Stages of CKD were based on eGFR and UACR categories recommended by the KDIGO 2012 guidelines: stage G1 for GFR ≥90 ml/min per 1.73 m², G2 60 to <90 ml/min per 1.73 m², G3a 45 to <60 ml/min per 1.73 m², G3b 30 to <45 ml/min per 1.73 m², G4 15 to <30 ml/min per 1.73 m², and G5 <15 ml/min per 1.73 m². For the purposes of this analysis, stages G3b, G4, and G5 were combined because of the low number of participants in each category. 3-year risk, risk of 40% eGFR decline or kidney failure (needing dialysis or kidney transplantation) in 2–3 years calculated using the Chronic Kidney Disease Prognosis Consortium equations; eGFR, eGFR calculated using the 2021 Chronic Kidney Disease Epidemiology Collaboration creatinine equations; KDIGO, Kidney Disease Improving Global Outcomes; UACR, urine albumin-to-creatinine ratio.