New urine biomarker predicts diabetic kidney disease

New urine biomarker predicts diabetic kidney disease

Biomarker in Urine Could Aid Early Diagnosis of Kidney Failure

Kidney Disease Scientists believe a new urine biomarker could help predict kidney disease earlier. caifas/Getty Images

The kidneys are vital organs that filter all the blood in the body for wastes, toxins, and excess fluids every 30 minutes. When the kidneys are damaged and no longer filter blood efficiently, it leads to chronic kidney disease (CKD). CKD can cause the accumulation of waste and excess fluid in the body, contributing to conditions like heart disease and stroke. It is estimated that around 15% of adults in the U.S. have CKD, but most cases remain undiagnosed. As CKD progresses, kidney function decreases, eventually leading to kidney failure, where patients require kidney transplants or dialysis for survival.

Currently, albumin, a protein produced by the liver, is an essential diagnostic marker for kidney disease. However, up to 50% of high-risk diabetes patients with CKD and kidney failure have low levels of albumin in their urine. Finding new biomarkers for kidney failure could significantly aid clinicians in diagnosing and treating CKD earlier, before it reaches advanced stages. Recent research has focused on urine levels of adenine, a metabolite produced by the kidneys, and its potential to predict kidney disease in people with diabetes.

A study published in The Journal of Clinical Investigation analyzed urine sample data from over 1,200 patients with diabetes and impaired kidney function from various research cohorts. The researchers found that higher levels of adenine in the urine were associated with higher rates of kidney failure, even in patients with low levels of albumin. Furthermore, higher adenine levels were also linked to a higher risk of all-cause mortality, indicating its impact on other areas of the body.

In another analysis, the researchers studied the effects of the antidiabetic drug empagliflozin on adenine levels in 40 patients with type 1 diabetes. After eight weeks of treatment, empagliflozin reduced adenine levels by 36.4%. This suggests that the drug’s benefits may be partly attributed to lower adenine levels and its potential to reduce the risk of CKD progression.

To further investigate the role of adenine in kidney failure risk, the researchers tested a drug that blocks a major adenine production pathway in mouse models of type 2 diabetes. The drug successfully reduced adenine levels, protected against kidney injury, and prevented thickening of kidney walls without affecting blood sugar levels.

Using a new technique called spatial metabolomics, the researchers conducted biopsies of kidneys from human patients with and without diabetes. They found that while healthy kidneys showed low levels of adenine, kidneys with diabetes had elevated levels in specific areas, such as scarred blood vessels. This observation highlights the potential of adenine as a biomarker for kidney failure.

Although the study has limitations, including its reliance on data from lab animals and a relatively small sample size, it provides robust evidence for the validity of adenine levels as a biomarker for kidney disease. However, further research is needed to determine the causal link between adenine and CKD progression.

The study’s findings have significant implications for early detection and intervention in CKD. By identifying individuals with early CKD at risk for disease progression, clinicians can introduce adenine-lowering drugs or other kidney protective interventions early on in treatment. This approach is particularly relevant for patients who currently do not exhibit traditional clinical markers of CKD but may still benefit from such interventions.

Dr. Donald A. Molony, a distinguished teaching professor at the University of Texas System, suggests that this study opens up new avenues for the development of therapeutics that can reduce the progression to kidney failure. He also emphasizes the importance of evidence-based interventions to improve kidney health and reduce the risk of kidney failure by 50-70%. These interventions include maintaining a healthy lifestyle, achieving healthy blood pressure, avoiding excessive use of pain relievers, and restricting animal-source protein in the diet.

Dr. Molony advises patients with additional kidney disease risks, such as diabetes, to regularly consult their primary care physician for kidney function assessments. If levels of albumin and other proteins in their urine are excessive, patients should consider timely consultation with a kidney specialist. While the urine test used in this study is not yet commercially available outside experimental conditions, its potential for early diagnosis and better treatment outcomes is promising.

In conclusion, the discovery of a new urine biomarker, adenine, offers hope for early diagnosis and improved treatments of kidney failure. This breakthrough research has identified a potent biomarker that may enable the identification of individuals with early CKD at risk for disease progression. By understanding the role of adenine and developing adenine-lowering drugs, researchers open up possibilities for reducing the risk of CKD and the need for kidney transplants or dialysis. This study emphasizes the importance of regular kidney function assessments and evidence-based interventions to improve kidney health and reduce the risk of kidney failure by a significant margin.