A Bibliometric and Visualized Analysis of Mitochondrial Research in Diabetic Nephropathy

Summary

This bibliometric analysis delineates the landscape of mitochondrial research in diabetic nephropathy (DN) and summarizes major thematic changes and emerging topics.

Abstract

This bibliometric study systematically maps the global landscape of mitochondrial research in DN from 2016 to 2025. To maintain consistency with the study title and search focus, DN is used as the primary term, whereas diabetic kidney disease (DKD) is retained only when describing search terms, screening criteria, or original author keywords. A total of 1,342 publications were retrieved from the Science Citation Index Expanded (SCI-EXPANDED) and Social Sciences Citation Index (SSCI) within the Web of Science Core Collection (WoSCC) and analyzed using CiteSpace, VOSviewer, and Scimago Graphica. Annual publication output increased nearly fourfold from 63 in 2016 to 239 in 2025, and dataset-level citation visibility also increased. China led in publication volume, whereas Australia and the United States showed higher average citations per paper, indicating a divergence between output and citation-based visibility. Central South University ranked first in institutional output and total citations among the institutions shown, but its collaboration connectivity was lower than that of Shanghai Jiao Tong University and Zhejiang University. Keyword and reference analyses showed a temporal expansion from high-glucose-induced oxidative stress and apoptosis to mitophagy, ferroptosis, mitochondrial dynamics, mitochondria-associated endoplasmic reticulum membranes (MAMs), and the NLRP3 inflammasome. Intervention-related and methodology-related topics, including SGLT2 inhibitors, MitoQ, caloric restriction, Mendelian randomization, and metabolomics, were also identified. Overall, mitochondrial research in DN has broadened toward mitochondrial quality control, regulated cell death, multi-omics approaches, and intervention-related topics. These bibliometric patterns indicate topic prominence and citation visibility rather than direct mechanistic or clinical evidence and may help identify directions requiring further validation.

Introduction

DN is one of the most severe microvascular complications of diabetes mellitus and a leading cause of end-stage renal disease worldwide^1,2. Despite substantial progress in glucose control, blood pressure management, and renin-angiotensin system blockade, the incidence of DN continues to rise, and a considerable proportion of patients still progress to irreversible renal failure³. This unmet clinical need has driven an intense search for novel pathophysiological mechanisms and therapeutic targets. Mitochondria serve as central hubs of cellular energy metabolism, redox homeostasis, and apoptosis, and have emerged as critical nodes in the pathogenesis of DN^4,5. Studies over the past two decades have established that hyperglycemia-induced mitochondrial dysfunction directly contributes to podocyte injury, tubular epithelial cell damage, mesangial expansion, and interstitial fibrosis^6,7. This dysfunction is characterized by excessive reactive oxygen species production, impaired oxidative phosphorylation, mitochondrial fragmentation, defective mitophagy, and dysregulated mitochondrial biogenesis^8,9. Consequently, mitochondria-related signaling pathways involving SIRT3, PGC1α, Drp1, PINK1, Parkin, and the NLRP3 inflammasome have become key research foci^10,11. Recently, emerging concepts such as ferroptosis, MAMs, and mitochondrial metabolic reprogramming have further expanded the mechanistic landscape of DN^12,13,14. The volume of publications on mitochondrial research in DN has increased substantially, generating a rich but increasingly complex and fragmented body of knowledge.

Given the rapid proliferation of literature, traditional narrative reviews are insufficient to systematically capture the evolving intellectual landscape, collaborative networks, and emerging frontiers of this field¹⁵. Bibliometric analysis, a quantitative and visualization-based approach, offers an objective means to map scientific outputs, identify influential papers, authors, institutions, and countries, and detect the dynamics of research topics over time^{16,17,18,19,20}. Several bibliometric studies have examined diabetic nephropathy, DKD, mitochondria-related kidney research, or oxidative stress-related topics^21,22,23,24. Nevertheless, an updated, topic-focused bibliometric synthesis of mitochondrial research in DN may still help clarify recent research activity, collaboration patterns, thematic evolution, and emerging topics in this specific field. In this study, all relevant publications were retrieved from the SCI-EXPANDED and SSCI within the WoSCC, covering the period from 2016 to 2025. CiteSpace, VOSviewer, and Scimago Graphica were employed to conduct a systematic bibliometric and visualization analysis. This study delineates the current research landscape and summarizes the evolution of major topics, including mitophagy, ferroptosis, mitochondrial dynamics, and intervention-related research, thereby providing a bibliometric basis for identifying directions that warrant further experimental and clinical validation.

Protocol

Data acquisition and search strategy

All bibliometric records were retrieved from the SCI-EXPANDED and SSCI within the WoSCC on April 30, 2026. SCI-EXPANDED was used to capture biomedical and life-science literature, while SSCI was retained to include potentially relevant interdisciplinary records. The search strategy was constructed with reference to the Medical Subject Headings (MeSH) database. “Diabetic Nephropathies” and “Mitochondria” were searched separately in MeSH, and the corresponding MeSH terms, entry terms, and related subheadings were reviewed to guide keyword selection and synonym expansion. Because Web of Science does not directly use MeSH indexing, the MeSH-derived terms were translated into topic-field search terms. The final search was performed using the following Boolean expression: TS=((“diabetic nephropathy” OR “diabetic nephropathies” OR “diabetic kidney disease” OR “diabetic kidney diseases” OR “diabetic kidney” OR “diabetic renal”) AND (mitochondria* OR mitochondrial* OR mitophagy OR “mitochondrial dysfunction” OR “mitochondrial dynamics” OR “mitochondrial fission” OR “mitochondrial fusion” OR “mitochondrial biogenesis” OR “mitochondrial quality control”)). Document types were restricted to articles and review articles, and the publication period was set from January 1, 2016, to December 31, 2025. This period was selected because it represented the most recent complete 10-year interval available at the time of retrieval, allowing the analysis to focus on contemporary developments in mitochondrial research in DN while avoiding potential bias from an incomplete 2026 publication year.

All records were exported in plain-text format with the “Full Record and Cited References” option selected. To reduce the inclusion of irrelevant records potentially retrieved through Keywords Plus, the titles, abstracts, and author keywords of all retrieved records were manually screened. Only records substantively related to mitochondrial research in DN or DKD were retained. Publications were excluded if DN or DKD was mentioned only as one of several diabetic complications or as background information, without kidney-related outcomes, renal cell models, renal tissue evidence, nephropathy-specific mechanisms, or a primary focus on DKD. After duplicate removal and manual screening according to the predefined inclusion and exclusion criteria, 1,342 eligible publications were included in the final analysis.

Analytical tools and mapping workflow

Basic statistical analyses and conventional charts, including bar charts, line charts, pie charts, and bubble plots, were generated using WPS Excel 2023 and GraphPad Prism 10.1. Annual publication output was summarized by publication year. Dataset-level annual Times Cited counts were obtained from the WoSCC citation report and defined as citations received in each calendar year by all 1,342 included records, rather than same-year citations to annual publication cohorts or field-wide annual citation totals. For country/region-level analyses, average citations per paper were calculated by dividing total citations by the number of publications for each country/region. This metric was interpreted as an unadjusted descriptive indicator of citation visibility within the retrieved dataset. It was not considered a direct measure of national research quality or academic influence, because citation counts may be influenced by publication year, citation window, journal platform, article type, study design, and field-specific citation practices.

Knowledge mapping was performed using VOSviewer 1.6.19, CiteSpace 6.4.R1, and Scimago Graphica 1.0.25. The databases, software, and online resources used for literature retrieval, bibliometric analysis, visualization, and journal metric retrieval are listed in the Table of Materials. Network analyses were conducted using the full counting method. The WoSCC plain text files were imported into VOSviewer to construct co-authorship networks at the country/region, institution, and author levels, as well as keyword co-occurrence and journal co-citation networks. For geographic visualization, the country/region co-authorship network generated in VOSviewer was exported as a Graph Modeling Language (GML) file and imported into Scimago Graphica, where a geographic layout was applied with a world map as the background. In this map, node size represented publication volume, and link thickness indicated collaboration intensity. The same WoSCC dataset was imported into CiteSpace for keyword-timeline clustering, reference co-citation clustering, and citation-burst detection to characterize the temporal evolution and intellectual structure of the field.

Parameter configuration in CiteSpace and VOSviewer

In CiteSpace, the time span was set from 2016 to 2025, with each time slice set to 1 year, yielding 10 slices in total. Node types were selected according to the analytical purpose, with Keyword used for keyword timeline and burst analyses, and Reference used for reference co-citation and burst analyses. The node selection criterion was set to the g-index with a scaling factor of k = 10, rather than a fixed Top N or Top N% threshold, to allow node selection to adapt to yearly citation or occurrence distributions while maintaining an interpretable network size^25,26. Pathfinder pruning was applied to the time-sliced networks and the merged network, whereas the Minimum Spanning Tree algorithm was not used. For burst detection, the decay factor γ was set to 0.5. In the reference co-citation clustering analysis, modularity Q and weighted mean silhouette values were calculated to describe the overall structure and cluster consistency of the pruned network.

In VOSviewer 1.6.19, all WoSCC plain text files were imported by selecting “Create a map based on bibliographic data” and “Read data from bibliographic database files,” with the file type specified as Web of Science. The full counting method was used. For co-authorship networks, the minimum publication threshold was set to 5 for countries/regions and institutions and to 3 for authors.

For institution-level analyses, institutional names were manually checked and harmonized according to the WoSCC affiliation records before network construction. The citation count for each institution was defined as the total WoSCC Times Cited count of publications attributed to that institution within the retrieved dataset. Abbreviated node labels generated in VOSviewer were further checked against the corresponding full institutional names to avoid ambiguity. For country/region analysis, the WoSCC country/region address field was used. Country/region names were manually harmonized for spelling variants and abbreviations. England, Scotland, Wales, and Northern Ireland were consolidated into the United Kingdom, and People’s Republic of China was shortened to China. Mainland China was reported as China, whereas Hong Kong Special Administrative Region (Hong Kong SAR), Macao SAR, and Taiwan were retained as separate regions if indexed separately by WoSCC; no post hoc merging was performed for country/region-level network analysis. For keyword co-occurrence analysis, the analysis unit was set to author keywords extracted from the WoSCC records, and the minimum occurrence threshold was set to 5; at this threshold, 89 keywords met the criteria. Before network generation, synonymous terms and abbreviations identified in the author-keyword list were manually standardized; for example, abbreviations for DN and reactive oxygen species were converted into their full terms. For journal co-citation analysis, cited sources were used as the unit of analysis, and a citation threshold was applied to retain an interpretable network of 53 journals. The layout was set to LinLog/modularity, with Attraction set to 2 and Repulsion set to -1. Node size was weighted by publication count, citation frequency, keyword occurrence, or co-citation strength according to the specific analysis. All network generation procedures were independently performed twice by the first and second authors using the same dataset and parameter settings to verify the stability of the results. In cases of notable discrepancies, the raw data and parameter settings were rechecked before reanalysis.

Results

Annual publication trends and dataset-level citation visibility

From 2016 to 2025, the annual number of publications on mitochondrial research in DN increased from 63 to 239. Dataset-level annual Times Cited counts for the fixed dataset increased from 49 in 2016 to 12,516 in 2025. This metric represents citations received in each calendar year by all included records, rather than same-year citations to annual publication cohorts or field-wide citation totals. Because this cita...

Discussion

This bibliometric study provides a systematic overview of the global research landscape and thematic evolution of mitochondrial research in DN from 2016 to 2025. The results show that research activity in this field increased over the past decade, particularly after 2021. During this period, the research focus gradually expanded from oxidative stress and mitochondrial dysfunction to mitochondrial quality control, metabolic adaptation, regulated cell death, organelle interactions, and translationally oriented therapeutic ...

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Web of Science Core Collection	Clarivate	https://www.webofscience.com/	Not applicable
VOSviewer	Leiden University	https://www.vosviewer.com/	1.6.19
CiteSpace	Drexel University	https://citespace.podia.com/	6.4.R1
Scimago Graphica	Scimago Laboratory	https://www.scimagographica.org/	1.0.25
WPS Excel	Kingsoft Corporation	https://www.wps.com/	2023
GraphPad Prism	GraphPad Software	https://www.graphpad.com/	10.1
Journal Citation Reports	Clarivate	https://jcr.clarivate.com/	Not applicable
Medical Subject Headings database	National Library of Medicine	https://www.ncbi.nlm.nih.gov/mesh/	Not applicable