Research trends and frontiers of the Apelin system in kidney diseases: a multi-database bibliometric analysis and...

Approximately 850 million individuals worldwide are diagnosed with kidney disease; however, current therapeutic options remain limited, and patient prognosis is still suboptimal. The Apelin system comprising the G protein-coupled receptor APJ and the ligands Apelin and Elabela, plays a critical role in the physiological and pathological regulation of renal function. However, the full involvement of the Apelin system in kidney disease remains unclear. This study aimed to characterize the current research on Apelin in renal diseases and validate the robustness of the findings through a multi-database comparative approach.

We searched the Web of Science Core Collection (SCI-EXPANDED) for publications from January 1, 2006, to October 18, 2025, and performed equivalent searches in Scopus and PubMed using the same keywords, timeframes, and eligibility criteria to ensure result stability and generalizability. Analyses were visualized using CiteSpace, the Bibliometrix R package, online bibliometric tools, and Excel software. Key elements included publication trends, contributions from countries, institutions, journals, highly global cited documents, and emerging research themes.

The number of related publications has increased rapidly, reflecting growing interest in the role of the Apelin system in kidney diseases. Of the top ten journals publishing on this topic, seven were in the Q1 category of Journal Citation Reports, indicating strong academic influence. Current research focuses on acute kidney injury, diabetic kidney disease, and chronic kidney disease. Mechanistically, studies have predominantly focused on factors such as inflammation, apoptosis, oxidative stress, blood pressure, and fibrosis. Cross-database validation revealed high consistency in annual publication trends, substantial keyword overlap, and stable geographical disease distribution.

This study offers a comprehensive overview of Apelin system research in kidney disease and provides key insights for future investigations.