How healthy are your kidneys? World Kidney Day 2025 highlights the importance of prevention, early screening, and timely treatment, especially for individuals with high blood pressure, diabetes, or high cholesterol—conditions that increase the risk of kidney disease.
According to Taiwan’s Health Promotion Administration (HPA) data from 2023, 30% of individuals over 40 with these conditions exhibited abnormal kidney function during health screenings. However, nephrologists warn that traditional kidney function tests have limitations in detecting early-stage kidney disease, making precise evaluation difficult. To improve early detection, experts recommend incorporating new biomarkers such as indoxyl sulfate (IS)—a protein-bound uremic toxin that can be measured without mass spectrometry, allowing for earlier diagnosis.
Chronic Kidney Disease: The Silent Killer
Early-stage chronic kidney disease (CKD) often has no obvious symptoms, earning it the nickname "silent killer." Dr. Hou Yi-Chou, a nephrologist at Cardinal Tien Hospital in New Taipei City, recently treated a 30-year-old man who had a history of hypertension and was taking heart medication. His routine health checkup revealed abnormal kidney function, prompting him to seek medical advice.
"He was a fitness enthusiast with a high-protein diet, which caused fluctuations in his creatinine levels and glomerular filtration rate (GFR). His initial GFR reading was 61.9, but 24 hours later, it rebounded to 77, making it difficult to assess his actual kidney function," Dr. Hou explained.
Further testing of indoxyl sulfate levels revealed concentrations five times higher than normal, leading to a kidney biopsy, which confirmed chronic kidney disease. Fortunately, with dietary adjustments and medication, his condition is now under control.
Limitations of Traditional Kidney Function Tests
Dr. Hou pointed out that many patients seek medical attention after abnormal health check results, but early detection of CKD remains a challenge.
Traditional markers like creatinine and GFR can be influenced by factors such as age, gender, muscle mass, and medication use, leading to unreliable results—particularly in muscular individuals, pregnant women, or those on certain medications.
Similarly, blood urea nitrogen (BUN) levels fluctuate based on protein intake, and factors like intense exercise, fever, urinary tract infections, and menstrual cycles can result in false-positive proteinuria findings.
To improve accuracy, doctors recommend incorporating indoxyl sulfate (IS) testing as an additional marker. Higher IS levels indicate greater kidney impairment and are less affected by muscle mass or diet, making them a more reliable early indicator of kidney damage.
Indoxyl Sulfate: A Key Tool for Diagnosis and Treatment Monitoring
Beyond early detection, measuring IS levels also helps track treatment effectiveness.
"If a patient’s IS levels do not decrease—or even rise—despite medication and dietary changes, it suggests poor treatment adherence or the need for a different approach," Dr. Hou explained.
Clinical observations indicate that with proper management, IS levels can drop by 20-30% within 1 to 3 months. If levels remain high, doctors must reassess the treatment plan.
Previously, testing for protein-bound uremic toxins like IS required complex mass spectrometry, but new, non-invasive methods are now available—making self-paid testing more affordable and accessible.
Take Action: Prioritize Your Kidney Health!
On World Kidney Day, doctors urge everyone—regardless of risk level—to take kidney health seriously and prevent CKD from developing unnoticed.
To promote early detection, Taiwan’s HPA has expanded free health screenings, now offering one kidney screening every five years for individuals aged 30-39. The program also includes kidney disease education sessions, with an estimated 3.2 million people expected to benefit.
As diagnostic technology advances, precision testing is playing an increasingly important role in identifying CKD early. Dr. Hou emphasized that detecting kidney dysfunction early is key to effective treatment. Even non-nephrology specialists—such as cardiologists and internists—can utilize kidney function screening tests to better assess patients with chronic diseases.
By raising awareness and adopting new diagnostic tools, more people can benefit from early detection and timely intervention, ultimately reducing the long-term burden of chronic kidney disease.
