24 h urine protein quantitative is the gold standard when it comes to determine the amount of urine protein, but the operation is complicated, time-consuming and vulnerable to pollution.In order to substitute for 24 h urine protein
In recent years, various authoritative guidelines in China (Chinese Preventive Medicine Association Kidney Disease Prevention and Control Professional Committee - "Chinese Guidelines for the Early Evaluation and Management of Chronic Kidney Disease", Chinese Medical Association - "Chinese Guidelines for Clinical Diagnosis and Treatment of Diabetic Kidney Diseases") and expert consensus (recommendations) (Diabetic Nephrology Expert Committee of the Endocrinology Professional Committee of the Chinese Association of Integrative Medicine - "Expert Consensus on the Prevention and Treatment of Diabetic Nephropathy with Integrated Traditional Chinese and Western Medicine (2023 Edition)", " Expert Recommendations on Clinical Pathways for Early Screening of Chronic Kidney Disease and Its Complications in Chinese Adults (2023 Edition) jointly recommended the determination of ACR, and proposed that ACR is the standard for early kidney disease screening and diagnosis and staging of chronic kidney disease due to various reasons, and can be carried out as a primary screening project.
The recommended auxiliary examination for early screening of CKD in children in China (2021 Edition) recommends that microalbuminuria be used as an indicator for early screening of CKD in children, and the measurement of urine albumin/urine creatinine (ACR) can be used for the detection of early microalbuminuria in children with CKD.
As early as 2019, the British Nephrology Association's "Glomerular diseases in pregnancy: pragmatic recommendations for clinical management" clinical practice guidelines for pregnancy also included UACR in the quantitative and graded recommendations for urine during pregnancy.
Tests for ACR can be used to:
(1) impaired charge barrier function of the marker assessment;
(2) Assessment of filtration membrane damage for various primary and secondary glomerular diseases;
(3) Treatment effect monitoring, such as diabetic nephropathy monitoring.
ACR and diabetes
Elevated ACR is an early indicator of diabetic complications, and urinary ACR can be used as one of the indicators for diagnosing diabetic nephropathy and renal impairment. Screening for diabetic nephropathy should be routinely performed annually. Type 1 diabetes is screened 5 years after diagnosis. Patients with type 2 diabetes mellitus can be diagnosed with renal lesions, and screening for urinalysis, urine microalbumin-to-creatinine ratio (ACR), and eGFR should be started immediately after diagnosis, and at least once a year thereafter. Diabetic nephropathy is diagnosed when a random urine albumin/creatinine ratio (UACR) of ≥ 30 mg/g is repeated over 3 to 6 months, and 2 out of 3 UACRs meet or exceed the cut-off value.
ACR and hypertension
ACR is a sensitive indicator for diagnosing the degree of early kidney injury in patients with early hypertension, and it is also an important indicator used to screen, evaluate and monitor the incidence of cardiovascular disease in patients with hypertension. ACR is markedly elevated in cardiovascular events (unstable angina, myocardial infarction, congestive heart failure, etc.), so ACR is valuable as an independent warning of cardiovascular events, and ACR testing is also necessary in such patients.
ACR and Systemic Lupus Erythematosus (SLE)
The urinary ACR level of SLE patients was significantly higher than that of healthy people, and ACR could be used as one of the early indicators of SLE kidney injury.
ACR and patients with chronic kidney disease
Urine albumin ACR measurement 3 times within 3 to 6 months, at least 2 times elevated, the diagnosis is positive.
ACR and pregnant women
Random ACR elevation is associated with adverse pregnancy outcomes in patients with gestational hypertension. Formal prenatal examination, close monitoring, early detection of the progress of gestational hypertension, do a good job of timely response. The Canadian College of Obstetricians and Gynecologists and the American Society of Hypertension have used ACR ≥30mg/mmol as one of the diagnostic criteria for preeclampsia. ACR has a high sensitivity for diagnosing gestational hypertension and early gestational diabetic nephropathy, so testing is recommended in pregnant women.