Assessment and treatment of metabolic acidosis in CKD: a registry-based study

Metabolic acidosis (MA) is common in patients with chronic kidney disease (CKD) and is associated with adverse effects. Despite guidelines recommending treatment, reports from Western countries have suggested that MA is often underdiagnosed and undertreated. However, the situation in Asia remains unclear. This study aims to assess the serum bicarbonate measurement rate and the prevalence, diagnosis, and treatment rates of MA in Asian CKD patients using the Japan chronic kidney disease database (J-CKD-DB-Ex). Patients included were aged 18 years or older and had an estimated glomerular filtration rate (eGFR) between 15 and 60 mL/min/1.73 m². We evaluated the rate of serum bicarbonate measurement in each year from 2014 to 2021. Among patients with at least one serum bicarbonate measurement during the study period, we assessed the prevalence of MA (serum bicarbonate < 22 mEq/L), and the diagnosis and treatment rates, based on ICD-10 codes and sodium bicarbonate prescriptions. The annual measurement rate of serum bicarbonate was consistently less than 10%. The prevalence of MA among patients with at least one serum bicarbonate measurement was 44.2%. Diagnosis and treatment rates in patients with MA were 8.6 and 7.5%, respectively. This study demonstrated that MA may be inadequately assessed and treated in Japanese patients with CKD.