National Japanese Registry Identifies Critical Diagnostic Blind Spot in Chronic Kidney Disease Management Protocols

Study shows serum bicarbonate is measured in fewer than 10% of CKD patients, leaving metabolic acidosis—a driver of kidney decline—largely untreated.

By: AXL Media

Published: Mar 17, 2026, 4:24 AM EDT

Source: Information for this report was sourced from Niigata University

The Hidden Complication of Renal Decline

Metabolic acidosis has long been recognized as a common and debilitating complication of chronic kidney disease (CKD), yet new real-world data suggest it is being systematically overlooked in clinical practice. The condition, characterized by an accumulation of acid in the body as kidney function falters, is a known driver of bone disease, insulin resistance, and heightened mortality. While international clinical guidelines explicitly recommend medical intervention when serum bicarbonate levels drop below 22 mEq/L, a nationwide registry from Japan indicates that the current standard of care fails to even identify the patients who meet these criteria. This lack of assessment means that a primary driver of renal deterioration is effectively hidden from clinicians during routine check-ups.

Alarming Disparities in Bicarbonate Monitoring

The study, led by researcher Mai Tanaka and conducted across 21 university hospitals, found that the annual measurement rate for serum bicarbonate was consistently below 10% between 2014 and 2021. Because testing is so infrequent, the reported prevalence of metabolic acidosis in general healthcare records appears artificially low, creating a false sense of security regarding the metabolic health of the CKD population. However, when researchers isolated the small subset of patients who actually received testing, a far more concerning reality was uncovered: nearly half of those measured met the clinical definition for metabolic acidosis. This suggests that the disease is not absent, but simply unmeasured in the vast majority of cases.

The Significant Gap Between Detection and Therapy

Even in the rare instances where metabolic acidosis was successfully identified through testing, the study highlighted a secondary failure in the transition from diagnosis to treatment. Among patients confirmed to have bicarbonate levels below the 22 mEq/L threshold, the actual rates of formal diagnosis and treatment were only 8.6% and 7.5%, respectively. This indicates a profound disconnect in the clinical workflow, where even measurable metabolic abnormalities are frequently ignored by treating physicians. The researchers emphasized that this gap represents a missed opportunity to slow the progression of kidney failure through inexpensive and widely available alkali therapies or targeted dietary intervent...