The Web of Science (WOS) database, developed and maintained by Clarivate Analytics (Philadelphia, PA, USA), was selected for data collection owing to its widespread use and suitability for bibliometric analysis (17). This study applied a subject term search methodology to conduct a literature search in the Web of Science Core Collection database (WoSCC). Based on searching the Medical Subject Headings (MeSH) and related literature (15, 18, 19), the search formula was set as TS = (“Non-alcoholic Fatty Liver Disease” OR “Nonalcoholic Fatty Liver Disease” OR “Metabolic Associated Fatty Liver Disease” OR “Metabolic-associated Fatty Liver Disease” OR “metabolic dysfunction-associated steatotic liver disease” OR “metabolic dysfunction associated steatotic liver disease” OR “Metabolic Steatohepatitis” OR “Nonalcoholic Steatohepatitis” OR “Non-alcoholic Steatohepatitis” OR “NAFLD” OR “MAFLD” OR “MASLD” OR “MASH” OR “NASH”) AND TS = (“Child*” OR “Pediatric*” OR “Paediatric*” OR “Infant*” OR “Newborn*” OR “Neonat*” OR “Preschool*” OR “Pubert*” OR “Adolescen*” OR “Teen*”). Within them, “Topic Search” was indicated by “TS”. The search criteria were identified as follows: the search date was restricted to January 1, 2004 to December 31, 2024; only English was accepted in terms of language; the document types were limited to articles or review articles; the search results were exported as plain-text files with customized fields, comprising authors, titles, sources, abstracts, keywords, institutional addresses, cited references, funding information, and other related information. The specific literature search procedure is illustrated in Figure 1.

VOSviewer is a software program designed by Nees Jan van Eck and Ludo Waltman to visualize the development of collaborations and themes in the field of research. In this study, the VOSviewer (version 1.6.20) software, developed by the Centre for Science and Technology Studies (CWTS) at Leiden University, the Netherlands, was used to conduct the following analyses: distribution of countries/regions, institutions, authors, journals, keywords, references, as well as collaborative analyses in the area of pediatric MASLD research. Citespace is a bibliometric software engineered by Professor Chaomei Chen and his collaborators that facilitates the visualization and analysis of sophisticated citation networks. In this study, the following analyses were performed utilizing CiteSpace (version 6.2.R4 advanced) software, developed by Dr. Chaomei Chen at Drexel University, Philadelphia, PA, USA: mainly the contribution and centrality of keywords and references. R language's bibliometrix package is a powerful and flexible tool that helps researchers perform intensive literature data analysis. In this study, Bibliometrix (R-Studio's R-Tool, version 4.3.2),an R package developed by Massimo Aria and Corrado Cuccurullo at the University of Rome Tor Vergata, Italy, was used to carry out the following analytical tasks: keywords, references, and collaborative network analysis. In addition, Microsoft Excel (version 2021), developed by Microsoft Corporation (Redmond, WA, USA), was used for data analysis of trends in annual publications.

The common bibliometric terms and the criteria for establishing them were as follows: (1) keywords for analysis were extracted from title, abstract, author's keyword, and keyword plus; (2) Node centrality evaluates a node's capacity to function as a connector between other nodes, underscoring its critical role in facilitating information exchange or knowledge transfer. In this analysis, CiteSpace was utilized to calculate node centrality, applying a default threshold of 1; (3) The H-index serves as a composite metric for evaluating the scholarly output and influence of authors or journals. In this analysis, authors' H-index values were calculated using Bibliometrix, while publication counts across countries/regions, authors, journals, and keywords were quantified by VOSviewer; (4) the term “co-cited” describes the occurrence of two or more publications being jointly referenced by subsequent publications, whereas co-citation refers to the observed phenomenon or the bibliometric technique for analyzing these co-occurrence patterns; (5) Citation burst denotes a significant increase in the citation frequency of a publication over a defined time interval. The default threshold in CiteSpace's Burstness function was maintained at default values, with γ set to 1. Finally, the top 20 keywords out of 134 and the top 10 references out of 583 were selected for analysis; (6) A dual-map overlay of journals was created through CiteSpace's overlay maps feature, leveraging the journal citation reports (JCR) dual map overlay (v.2.2) platform. The visualization integrated a JCR base map comprising 10,330 journals, courtesy of Loet Leydesdorff.

The systematic literature search initially retrieved 4,307 records after applying temporal constraints and executing the search query. Limiting the results to English-language publications reduced the count to 4,255. Further refinement by restricting the document type to “article” or “review article” yielded 3,482 publications. Finally, after excluding other document types, such as proceeding papers, a final total of 3,409 relevant publications on MASLD in children remained, including 2,697 articles and 712 reviews. These articles were derived from 562 countries or regions and published in 967 journals. As indicated in Figure 2, a number of annual publications showed a general upward trend between 2004 and 2024, while a slight reduction in 2023, but the number apparently rebounded to the peak in 2024. Particularly from 2012 to 2014 and 2020 to 2022, the increase was relatively significant. The increase from 2016 to 2020 was more moderate, despite a slight decline in publications from 2014 to 2016 and a marginal decrease in 2019. According to the polynomial trendline, the cumulative volume of publications in pediatric MASLD maintained a high growth tendency.

The field of pediatric MASLD research covers 562 countries or regions. To identify the countries or regions with the most prominent contributions to the field, VOSviewer was used to analyze the top 30 countries and regions, which is illustrated in Figure 3A; among them, the United States top globally in publications, Italy emerges in second, and China follows in third, and the most vital connections are between United States and Italy, as well as United States and China, closely followed by United States and England, there are also considerable cooperation between Italy and England. In bibliometrics, centrality is a measure of the perceived weight of a node in a network, and according to the results of CiteSpace analysis, the quantity of publications and centrality are factors considered to ascertain the most significant 5 countries or regions, respectively, and the top 5 countries or regions are listed in Table 1. The United States led in terms of the volume of publications (n = 1,145 publications), meanwhile it ranked first in terms of centrality with a share of 0.29.

The analysis of research institutions seeks to capture the worldwide dissemination of research associated with the pediatric MASLD field as a reference for researchers seeking collaborations. The top 5 institutions are ranked according to the number of publications as well as centrality, which are shown in Table 2, and the University of California System had both the largest volume of publications (n = 214), as well as the highest centrality with a centrality share of 0.14. In addition, the Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) ranked second in publications (n = 202), and it tied with University of California System for first place in terms of centrality. As illustrated in Figure 3B, the VOSviewer analysis reveals that institutional collaborations can be broadly categorized into six closely related blocks.

The active authors and co-cited authors analysis assist in identifying critical figures in the field of pediatric MASLD. Co-cited authors are commonly scholars with high influence in the same field, and their research achievements are recognized as instrumental to the development and promotion of the field. The first 5 authors and co-cited authors are shown in Table 3 for their respective publication volumes and institutions. Among them, Valerio Nobili (Bambino Gesu Pediat Hosp, Italy) had the maximum amount of publications with a total of 169 papers, and he was the pioneer in the field of pediatric MASLD, Anna Alisi (Children's Hosp & Res Inst Bambino Gesu, Italy) ranked second with a volume of 121 publications and Jeffrey Schwimmer (Univ Calif San Diego, USA) ranked third with 74 publications. By analyzing the co-cited authors, it could be concluded that Jeffrey Schwimmer (n = 2,004), a scholar from the USA, had the highest citation level and had made a major contribution to the field of pediatric MASLD, with Valerio Nobili (n = 1,855) in the second rank, and Zobair Younossi (n = 860) in the third rank. It was noteworthy that Valerio Nobili ranked first for the quantity of publications in this area and ranked second in terms of citation level.

The collaborations of the authors of literature on pediatric MASLD are displayed in VOSviewer (Figure 4A), which can be roughly divided into 9 clusters centered on Valerio Nobili and Jeffrey Schwimmer. The network map of co-cited authors indicated a high degree of homogeneity in the study focus of authors in the literature on pediatric MASLD (Figure 4B), which could be divided into 4 main clusters.

A bibliometric analysis of journals and co-cited journals in the domain of pediatric MASLD allowed for the identification of highly productive and influential journals. The list of the top 5 journals with the highest number of publications is summarized in Table 4. Journal of Pediatric Gastroenterology and Nutrition (IF 2.4, Q3/Q1) was the most productive journal in terms of quantity, ranking first with a total of 125 publications. Hepatology (IF 13, Q1) and World Journal of Gastroenterology (IF 4.3, Q1) were the second and third journals with 77 and 62 publications. The 5 most co-cited journals with the highest frequency of citations are displayed in Table 5, and the top 3 journals were Hepatology (IF 13, Q1), Journal of Hepatology (IF 26.8, Q1), and Gastroenterology (IF 26.3, Q1). As evidenced, a multitude of studies on pediatric MASLD have been conducted based on the outcomes of research published in these journals.

The results of journals and co-cited journals in the domain of pediatric MASLD were visualized and analyzed by VOSviewer. Figure 5A shows the distribution of journals that study pediatric MASLD and the relationship between them, which could be mainly divided into 3 clusters indicated by various colors. Journal of Pediatric Gastroenterology and Nutrition and Hepatology, Nutrients emerged as the centers of the various clusters, and they were also tightly connected to each other. Figure 5B shows the distribution of cited journals and the association, which can be categorized roughly into 4 clusters, with Hepatology being the most prominent node and closely related to Gastroenterology and Journal of Hepatology. Via CiteSpace analysis, Figure 5C shows the dual-map overlay of journals on the pediatric MASLD field. On the left of the figure was a collection of citing journals, representing the current knowledge front, and on the right was a collection of cited journals, representing the knowledge foundation of the research area. The connecting lines between them reflected the macro structural development pattern of the field, indicating that research in pediatric MASLD exhibits a macroscopic development model characterized by the intersection of disciplinary themes.

Keyword analysis is an essential component of bibliometrics, contributing to our knowledge of the frontiers and hotspots of the research field. Table 6 displays the top 20 keywords ranked by frequency of occurrence, with “non-alcoholic fatty liver disease” (n = 1,379) having the highest frequency of occurrence, followed by “obesity” (n = 622) and “children” (n = 493). Visual analysis of the keywords by VOSviewer resulted in a co-occurrence network map, as shown in Figure 6A, with approximately seven clusters represented by distinct colors. In particular, the red clusters were primarily associated with pathological alterations, such as “non-alcoholic steatohepatitis”, and “cirrhosis”. The purple clusters were associated with obesity, such as “adolescent”, “overweight”, and “body mass index”. The green clusters were mainly related to clinical tests and diagnostics, such as “ultrasonography”, “alanine aminotransferase”, “liver biopsy”. The keyword word cloud generated according to the R-studio software is shown in Figure 6B. A word cloud is a visualization approach used to show the frequency of keywords in textual data, which is very intuitive and straightforward, and usually, the keywords are visualized in the same size as the frequency of their occurrence; hence, “insulin-resistance”, “children”, “metabolic syndrome”, “steatohepatitis”, “prevalence”, for example, are popular research topics in the area.

The keywords were visualized and analyzed by CiteSpace, and a keyword timeline graph (Figure 6C) was derived. The timeline graph displayed the keywords that appeared most frequently in the various clusters throughout a specific period, indicating that the keywords in the field of pediatric MASLD research could be classified into 11 clusters, of which the earliest and largest cluster was #0 (gut microbiota), the keyword “apoptosis” appeared previously, and “gut microbiome” was a relatively updated keyword from 2022 onwards. Another critical clustering was #1 (hepatocellular carcinoma), an axis where the previous keyword was “hepatocellular carcinoma”, but “outcome” was at the forefront. Eight clusters are still in progress, including #0 (gut microbiota), #1 (hepatocellular carcinoma), #2 (childhood), #3 (transient elastography), #4 (vitamin e), #5 (insulin sensitivity), #6 (nonalcoholic fatty liver disease), #7 (vitamin d). Figure 6D shows the Top 20 keywords with the strongest citation bursts. It was worth noting that the keywords that were more popular in the last few years were “pediatric gastroenterology”, “outcome”, “hepatology” and “diagnosis”. In contrast, the keyword with the highest burst strength was “steatohepatitis” at 23.84. The second was “intima media thickness”, with a burst strength of 11.97.

Co-cited references analysis, a core feature of CiteSpace, identifies pivotal research clusters or paradigms within a field by quantifying the co-citation frequency between publications. Highly co-cited references typically represent foundational studies in the discipline. The top 10 articles in the domain of pediatric MASLD in terms of co-citation frequency are listed in Table 7, where the top co-cited publication was published in the Journal of Pediatric Gastroenterology and Nutrition in 2017 by Miriam Vos, et al. This publication was a clinical practice guideline for the identification and management of pediatric MASLD. The publication detailed the diagnostic criteria, etiology, assessment methods, and treatment strategies for pediatric MASLD, and played an essential role in helping physicians and clinicians identify and manage pediatric MASLD better (20). The second-ranked publication was also a clinical guideline that provided clinicians with a reliable basis for diagnosing, treating, and preventing MASLD (21). The third-ranked publication was a meta-analysis that analyzed the prevalence of MASLD in children or adolescents between the ages of 1 and 19 years and the correlation with factors such as body mass index (BMI) (22). Among the other seven publications, three studies investigated the prevalence of MASLD in children or adolescents, along with related outcomes and trends (4, 23, 24); two articles proposed recommendations for renaming NAFLD to MAFLD (26, 27), and the remaining two explored the diagnostic and therapeutic aspects of MASLD in this age group.

As illustrated in Figure 7A, CiteSpace software was utilized to analyze and generate a network map, where every single node referred to a publication, the magnitude of a node reflected its citation frequency, the connectivity between the nodes showed the existence of a co-occurrence relationship between them, and the variation in node color represented the time of the publication's appearance. As seen in Figure 7B, the publications can be classified into 22 clusters depending on the degree of association between them, and the lines in red with arrows reflect the previous origins of the clusters. The most important and earliest cluster to emerge was #0 (probiotics), which developed 4 clusters, including #1 (nonalcoholic steatohepatitis), #2 (nonalcoholic fatty liver disease), #3 (MAFLD), #8 (docosahexaenoic acid), the clustering that immediately follows were #1 (nonalcoholic steatohepatitis), #2 (nonalcoholic fatty liver disease), the more contemporary research clustering were #19 (lysosomal acid lipase deficiency), #20 (immune checkpoint inhibitor), #21 (peroxisome proliferator-activated receptor-gamma). Figure 7C shows the topics in the top 20 references with the strongest citation bursts. The analysis revealed that there were 7 publications that were still in the thermal phase, and the most significant and longest-lasting citation burst after 2019 was a practice guidance authored by Naga Chalasani, et al. and published in Hepatology, with a burst strength of 49.81. Immediately following this was an article published in Nature Reviews Gastroenterology & Hepatology, with a burst strength of 40.04. The most recent article was authored by Mohammed Eslam and published in 2021.

The link between the three variables was shown by the three-field plot analysis, which includes references, authors, and keywords. The intensity of the associations was indicated by the width of the connecting lines, while the height of the rectangles represents the amount of publications. As illustrated in Figure 8, Valerio Nobili, Anna Alisi, and Jeffrey Schwimmer ranked among the top three based on the width of their entries, which indicates a higher frequency, while these authors also referenced highly cited references. Valerio Nobili extensively cited several of the references listed on the left in his own articles, with the most frequently cited being David Kleiner's article published in 2005. Meanwhile, Valerio Nobili's study involved the keywords “children” and “nonalcoholic fatty liver disease” with high frequency, as well as “obesity”, “insulin resistance”, “metabolic syndrome” and “fibrosis”.

Keyword and citation analysis is the core content and advantage of bibliometric research, which can help fellows to understand the dynamics and focus of the field quickly and to catch the core literature and emerging research directions. According to Table 6; Figure 6, the keyword analysis indicates that in the field of pediatric MASLD study, the pathological lesions of the liver, the connection with obesity, the complications, and comorbidities, the diagnosis and treatment of MASLD are the focus of the researchers. The gut microbiota has emerged as a prominent and enduring research focus within this domain, evidenced by its sustained high citation frequency over an extended period. Still, the newest hotspots in the last few years mainly focus on the diagnosis, risk, and outcomes of pediatric MASLD.

To the greatest extent of our understanding, this is the first study that explores academic developments and hot spots in pediatric MASLD from 2004 to 2024, utilizing a bibliometric method and visualization study. However, this paper has some limitations due to various factors. Initially, only one database was analyzed in this study, although WoSCC has precedent for use in bibliometric studies. Secondly, due to challenges in data standardization and language processing, only English literature was selected for analysis, which may have affected the results. Finally, our findings are time-sensitive due to the dynamic updating of the WoSCC database and the lag in the publication of literature. In addition, the diversity of the names of the organizations may cause bias in the research data. Whereas these inevitable flaws and deficiencies are visible, this study conducted the most insightful exploration and analysis of the current state of research in pediatric MASLD.