UACR: Its Time Has Come

From the Chair

The urine-albumin-creatinine ratio (UACR) is an estimate of urine albuminuria over a 24-hour timeframe and is expressed as the “excretion of albumin in milligrams per gram of creatinine.” The UACR is a major predictor of both kidney progression and cardiovascular events.

Approximately 90% of patients with hypertension and/or diabetes undergo estimated glomerular filtration rate (eGFR) testing. However, UACR is majorly undermeasured.^1-3 Only about one-half of patients with diabetes undergo UACR testing. The rate is even lower (approximately 10%) among patients with hypertension. Why is UACR measurement important?

In the chronic kidney disease (CKD) Heat Map provided by the National Kidney Foundation (NKF), the UACR and GFR stages define risk in patients with CKD.⁴ Estimating GFR and measurement of UACR allow for early detection of CKD among individuals at risk for CKD, especially those with diabetes or hypertension, and particularly among specific minority groups (eg, Black, Asian, and Latino patients). Measuring eGFR and UACR is now a key component of guideline-directed medical therapy for patients with CKD from type 2 diabetes (T2D).

Reports suggest that the underutilization of newer therapies for slowing progression of CKD in T2D may be due, in part, to under-recognition of CKD in patients with T2D.^5-9 Perhaps the 15% utilization of sodium-glucose cotransporter-2 inhibitors (SGLT2i) and 2% to 3% utilization of nonsteroidal mineralocorticoid receptor antagonists could improve if there is a major uptick in UACR measurement?

In a recent paper published in JAMA Open Access,¹⁰ Chu and colleagues reported that among adults with hypertension or diabetes and albuminuria, approximately two-thirds did not undergo urine albumin testing. According to the authors, albuminuria testing was associated with higher adjusted odds of receiving angiotensin-converting enzyme inhibitor or angiotensin receptor blocker treatment (odds ratio [OR], 2.39; 95% CI, 2.32-2.46) or SGLT2i treatment (OR, 8.22; 95% CI, 7.56-8.94) and having blood pressure controlled to less than 140/90 mm Hg (OR, 1.20; 95% CI, 1.16-1.23). This paper reinforces the need for routine UACR testing, especially among high-risk patients.

The NKF, along with the National Committee for Quality Assurance (NCQA), developed the Kidney Health Evaluation for Patients With Diabetes (KED) as a measure in the Healthcare Effectiveness Data and Information Set (HEDIS). This resource is targeted for rollout later this year.

The consequences of UACR becoming a HEDIS measure are multifold. In 2023, the Centers for Medicare & Medicaid Services will make KED a measure in the Medicare Merit-based Incentive Payment System. Linking UACR measurement to payments for services covered by Medicare Part B creates a clear incentive. Also in 2023, as part of the Diabetes Recognition Program, the KED measure will contribute to crediting clinicians for providing high-quality ambulatory care to their patients with diabetes. The KED will be incorporated into the Medicare Star Rating system, a consumer-facing assessment of clinicians, in 2024.

The NKF and NCQA should be congratulated for their tremendous work on behalf of patients with CKD. Finally, for UACR, its time has come.

References

1. Alfego D, Ennis J, Gillespie B, et al. Chronic kidney disease testing among at-risk adults in the U.S. remains low: real-world evidence from a national laboratory database. Diabetes Care. 2021;44(9):2025-2032. doi:10.2337/dc21-0723
2. Shin JI, Chang AR, Grams ME, et al; CKD Prognosis Consortium. Albuminuria testing in hypertension and diabetes: an individual-participant data meta-analysis in a global consortium. Hypertension. 2021;78(4):1042-1052. doi:10.1161/HYPERTENSIONAHA.121.17323
3. Stempniewicz N, Vassalotti JA, Cuddeback JK, et al. Chronic kidney disease testing among primary care patients with type 2 diabetes across 24 U.S. health care organizations. Diabetes Care. 2021;44(9):2000-2009. doi:10.2337/dc20-2715
4. Kidney numbers and the CKD Heat Map. National Kidney Foundation. Accessed August 8, 2023. https://www.kidney.org/kidneydisease/siemens_hcp_quickreference
5. Chu CD, Powe NR, McCulloch CE, et al; Centers for Disease Control and Prevention Chronic Kidney Disease Surveillance Team. Trends in chronic kidney disease care in the US by race and ethnicity, 2012-2019. JAMA Netw Open. 2021. doi:10.1001/jamanetworkopen.2021.27014
6. Murphy DP, Drawz PE, Foley RN. Trends in angiotensin-converting enzyme inhibitor and angiotensin II receptor blocker use among those with impaired kidney function in the United States. J Am Soc Nephrol. 2019;30(7):1314-1321. doi:10.1681/ASN.2018100971
7. Chu CD, Powe NR, McCulloch CE, et al; Centers for Disease Control and Prevention Chronic Kidney Disease Surveillance Team. Angiotensin converting enzyme inhibitor or angiotensin receptor blocker use among hypertensive US adults with albuminuria. Hypertension. 2021;77(1):94-102. doi:10.1161/HYPERTENSIONAHA.120.16281
8. McCoy IE, Han J, Montez-Rath ME, Chertow GM. Barriers to ACEI/ARB use in proteinuric chronic kidney disease: an observational study. Mayo Clin Proc. 2021;96(8):2114-2122. doi:10.1016/j.mayocp.2020.12.038
9. Lamprea-Montealegre JA, Madden E, Tummalapalli SL, et al. Prescription patterns of cardiovascular- and kidney-protective therapies among patients with type 2 diabetes and chronic kidney disease. Diabetes Care. 2022;45(12):2900-2906. doi:10.2337/dc22-0614
10. Chu CD, Xia F, Du Y, et al. Estimated prevalence and testing for albuminuria in US adults at risk for chronic kidney disease. JAMA Network Open.2023. doi:10.1001/jamanetworkopen.2023.26230