Kidney health checks: Whose role is it anyway?

Cardiovascular, kidney and metabolic conditions are closely connected. Problems in one system often drive deterioration in another, creating a vicious cycle that accelerates disease progression. In this commentary, the authors explore the key tests for chronic kidney disease (CKD), with information to help improve patient care.

What is the uACR test?

The urine albumin-to-creatinine ratio (uACR) test measures the amount of a protein called albumin in the urine.

In healthy kidneys, only a small amount of albumin is filtered from the blood into the urine. In the early stages of CKD, the amount of albumin leaking into the urine is abnormal (increased), but still very small. A simple urine dipstick test strip will not be sensitive enough to detect any changes – the sample needs to be sent to a laboratory for testing.

There are three recognised stages of albuminuria:

• A1 – normal to mildly increased urine protein levels (lower than 3 mg/mmol).
• A2 – moderately increased urine protein levels (3–30 mg/mmol).
• A3 – severely increased urine protein levels (>30 mg/mmol).

What is the eGFR blood test?

The main function of the kidneys is to clear water-soluble waste products (such as creatinine) from the blood. The efficiency of clearance is measured using the glomerular filtration rate (GFR). By using a blood test to measure creatinine levels, alongside other information such as height, weight and sex, a person’s estimated GFR (eGFR) can be calculated.

Healthy kidneys typically filter more than 90 mL each minute (adjusted for body size). A lower rate than this may indicate CKD.

Why is measuring eGFR and uACR important?

uACR and eGFR measurements are of equal importance in diagnosing the stage of CKD and the long-term risk of kidney failure. However, uACR is more sensitive in detecting early nephron loss, making it an invaluable test for detecting CKD early.

Figure 1 illustrates the importance of measuring uACR as an early detector of CKD. In early-stage CKD, nephron mass is likely already reduced even though the eGFR appears normal. By the time eGFR reaches 60 mL/min/1.73 m², nephron mass could have fallen – irreversibly – by as much as 80%. In contrast, a uACR at the clinical threshold of 3 mg/mmol will identify CKD much earlier, whilst nephron mass is still largely preserved, allowing intervention to slow CKD progression and protect kidney and cardiovascular health.

Recent research has also found that uACR is an independent predictor of cardiovascular disease, such as coronary artery disease, stroke, heart failure and arrhythmias, and microvascular disease (Barzilay et al, 2024). Thus, earlier detection of albuminuria also enables earlier intervention to improve cardiovascular outcomes.

A tool developed by Boehringer Ingelheim in collaboration with KDIGO (available at: https://kdigo-uk.vercel.app/) enables clinicians to stratify both cardiovascular and CKD risk by entering eGFR and uACR values. Outputs include the frequency of monitoring required and the risk of all-cause mortality, heart failure, kidney failure requiring replacement therapy, hospitalisation and myocardial infarction/stroke, and the tool also links to relevant guidelines.

uACR measurement remains the least achieved care process

Despite the importance of uACR as a risk predictor for multiple conditions, and despite its inclusion in the 9 key care processes recommended by NICE (2023a and 2023b) for people with diabetes, testing rates remain low. In 2024–25, whilst HbA_1c testing was completed in 91.9% of people with type 2 diabetes, uACR was only measured in 68.6% (NHS Digital, 2026). This rate was even lower in people with type 1 diabetes, at 54.8%. You can view your local levels of uACR testing at the National Diabetes Audit.

A number of barriers underlie this low rate of testing (Table 1). People living with diabetes and CKD have also highlighted the importance of wanting to understand the connection between diabetes and kidney disease, and the interventions available to prevent diabetes complications (Figure 2).

To build on the knowledge above and learn more about the risk factors, tests, and management of people living with diabetes and/or CKD, as well as patient stories, please view our two mini-modules on kidney health and kidney disease, co-created with Diabetes UK (available at: https://cpd.diabetes.org.uk/node/157).