Metabolic acidosis, a complication of chronic kidney disease, may be underassessed and undertreated in Japanese patients, according to a nationwide registry study published in Scientific Reports.
Using data from the Japan Chronic Kidney Disease Database Extension, which includes records from 21 university hospitals, researchers evaluated 179,444 adults with chronic kidney disease and an estimated glomerular filtration rate of 15 to 60 mL/min/1.73 m² (stages G3a, G3b, and G4).
They assessed patterns of annual serum bicarbonate measurements, the prevalence of metabolic acidosis (defined as serum bicarbonate levels below 22 mEq/L among patients with available measurements), and rates of diagnosis and treatment from 2014 to 2021. Across an average annual cohort of 58,010 patients, serum bicarbonate was measured at least once in 8% to 9% of patients each year.
Among 22,309 patients with at least one measurement during the study period, 44% had metabolic acidosis. Prevalence increased with chronic kidney disease stage, affecting 32% of patients in G3a, 46% in G3b, and 66% in G4.
However, few patients with metabolic acidosis were formally diagnosed or treated. Overall, 9% received a diagnosis and 8% were treated. Rates increased with disease severity, with diagnosis rising from 5% in G3a to 7% in G3b to 14% in G4, and treatment increasing from 4% to 5% to 13%, respectively.
Patients who underwent serum bicarbonate testing tended to be older (mean age, 73 years) and had more advanced kidney disease, higher levels of proteinuria, and higher rates of diabetes, hypertension, and heart failure compared with those who were not tested. They were also more likely to receive renin–angiotensin system inhibitors, diuretics, and statins.
The study had several limitations. The registry included data only from university hospitals and may not reflect practices in community settings. In addition, the analysis relied on serum bicarbonate values and did not include pH or anion gap measurements. Treatment data did not capture the use of sodium citrate, potassium citrate, or dietary interventions.
The researchers concluded that metabolic acidosis is not routinely assessed or managed in Japan despite its association with worsening kidney function. “These findings support the importance of improving clinical management, including serum bicarbonate measurement and diagnosis, to enhance the treatment of [metabolic acidosis] … which may potentially benefit patients with [chronic kidney disease],” the researchers wrote.
The researchers reported no conflicts of interest.
Source: Scientific Reports
