Molecular hydrogen and kidney diseases: a scoping review based on scientometry and data analytics

Acute kidney injury and chronic kidney disease impose substantial burdens on healthcare systems worldwide. Molecular hydrogen (H2) has emerged as a potential therapy due to its selective antioxidant, anti-inflammatory, and antiapoptotic properties. The present study reviews evidence on H₂-based renal interventions, examining therapeutic mechanisms, bibliometric trends, and existing research gaps based on data analytics. This scoping review integrates quantitative bibliometric analysis with qualitative thematic synthesis. This integration, uncommon in conventional scoping reviews, reveals important gaps. Following the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines, 69 publications were identified through Scopus and Web of Science. These publications mostly originated from Asia, particularly China and Japan, with clear peaks of activity in 2019 and 2024, but international collaboration remains limited. H₂ consistently demonstrated protective effects against apoptosis, fibrosis, inflammation, and oxidative stress across acute kidney injury, nephrotoxicity, transplantation, and early chronic kidney disease models. Our findings suggest that hydrogen therapy holds promise for renoprotection in both acute kidney injury and chronic kidney disease. Nonetheless, more robust clinical trials and standardized research methodologies are imperative to facilitate its broader adoption into clinical nephrology practice.