Bibliometric Analysis of Studies on Coffee/Caffeine and Sport

Epigenetics research in eye diseases: a bibliometric analysis from 2000 to 2023

CLINICAL RELEVANCE

A bibliometric analysis is a quantitative study that utilises methods such as citation analysis to evaluate research performance. A bibliometric analysis could provide a valuable reference for ophthalmic researchers to understand the trends in epigenetics research.

BACKGROUND

The number of studies on epigenetics in eye diseases has exceeded 5,000, but the progress and scope of epigenetic research on eye diseases remain unclear. The study aimed to bibliometrically analyse epigenetic research conducted in eye diseases.

METHODS

Studies concerning epigenetic research on eye diseases from 2000-2023 were searched using the Web of Science Core Collection. Following this, the included studies were analysed for citations, journals, keywords, authors, and countries, using the Bibliometrix package in R Studio.

RESULTS

In total, 3758 studies were included in the analysis, including 3099 original articles, 599 reviews, 11 editorials, and 49 early access articles. Investigative Ophthalmology & Visual Science was the most published journal with 185 articles, and Proceedings of the National Academy of Sciences of the United States of America was the most cited journal, with 8727 citations. The journal with the highest h-index was Oncogene (h-index = 38).Renu A Kowluru from the Kresge Eye Institute, Wayne State University, Detroit, USA, had the most citations with 1,690 and the highest h-index (h-index = 23). China and the USA were the countries with the highest number of publications (1739) and total citations (40533), respectively. Furthermore, from 2000-2023, the top five frequent research topics were diabetic retinopathy, 522; microribonucleic acid, 469; retinoblastoma, 370; apoptosis, 268; and epigenetics, 206.

CONCLUSIONS

The results of this bibliometric study provide the current status and trends of epigenetic research in eye diseases and will help researchers identify areas of current interest in the field, which should help highlight new research directions.

Influence of the CYP1A2 c.-163 A > C polymorphism in the effect of caffeine on fat oxidation during exercise: a pilot randomized, double-blind, crossover, placebo-controlled trial

PURPOSE

The aim of this study was to determine the influence of the CYP1A2 c.-163 A > C (rs762551) polymorphism on the effect of oral caffeine intake on fat oxidation during exercise.

METHODS

Using a pilot randomized, double-blind, crossover, placebo-controlled trial, 32 young and healthy individuals (women = 14, men = 18) performed an incremental test on a cycle ergometer with 3-min stages at workloads from 30 to 70% of maximal oxygen uptake (VO2max). Participants performed this test after the ingestion of (a) placebo; (b) 3 mg/kg of caffeine; (c) 6 mg/kg of caffeine. Fat oxidation rate during exercise was measured by indirect calorimetry. The influence of the CYP1A2 c.-163 A > C polymorphism in the effect of caffeine on fat oxidation rates during exercise was established with a three-way ANOVA (substance × genotype × intensity).

RESULTS

Eight participants were genotyped as AA, 18 participants were CA heterozygotes, and 6 participants were CC. There was a main effect of substance (F = 3.348, p = 0.050) on fat oxidation rates during exercise with no genotype effect (F = 0.158, p = 0.959). The post hoc analysis revealed that, in comparison to the placebo, 3 and 6 mg/kg of caffeine increased fat oxidation at 40-50% VO2max in AA (all p < 0.050) and 50-60% VO2max in CA and CC participants (all p < 0.050).

CONCLUSION

Oral intake of 3 and 6 mg/kg of caffeine increased fat oxidation rate during aerobic exercise in individuals with AA, CA and CC genotypes. This suggests that the effect of caffeine to enhance fat oxidation during exercise is not influenced by the CYP1A2 c.-163 A > C polymorphism.

TRIAL REGISTRATION

The study was registered on clinicaltrials.gov with ID: NCT05975489.

Genetic correlation between circulating cytokines and risk of three ophthalmic diseases: a bidirectional two-sample Mendelian randomization study

PURPOSE

Pathogenesis and the associated risk factors of cataracts, glaucoma, and age-related macular degeneration (AMD) remain unclear. We aimed to investigate causal relationships between circulating cytokine levels and the development of these diseases.

PATIENTS AND METHODS

Genetic instrumental variables for circulating cytokines were derived from a genome-wide association study of 8293 European participants. Summary-level data for AMD, glaucoma, and senile cataract were obtained from the FinnGen database. The inverse variance weighted (IVW) was the main Mendelian randomization (MR) analysis method. The Cochran's Q, MR-Egger regression, and MR pleiotropy residual sum and outlier test were used for sensitivity analysis.

RESULTS

Based on the IVW method, MR analysis demonstrated five circulating cytokines suggestively associated with AMD (SCGF-β, 1.099 [95%CI, 1.037-1.166], P = 0.002; SCF, 1.155 [95%CI, 1.015-1.315], P = 0.029; MCP-1, 1.103 [95%CI, 1.012-1.202], P = 0.026; IL-10, 1.102 [95%CI, 1.012-1.200], P = 0.025; eotaxin, 1.086 [95%CI, 1.002-1.176], P = 0.044), five suggestively linked with glaucoma (MCP-1, 0.945 [95%CI, 0.894-0.999], P = 0.047; IL1ra, 0.886 [95%CI, 0.809-0.969], P = 0.008; IL-1β, 0.866 [95%CI, 0.762-0.983], P = 0.027; IL-9, 0.908 [95%CI, 0.841-0.980], P = 0.014; IL2ra, 1.065 [95%CI, 1.004-1.130], P = 0.035), and four suggestively associated with senile cataract (TRAIL, 1.043 [95%CI, 1.009-1.077], P = 0.011; IL-16, 1.032 [95%CI, 1.001-1.064], P = 0.046; IL1ra, 0.942 [95%CI, 0.887-0.999], P = 0.047; FGF-basic, 1.144 [95%CI, 1.052-1.244], P = 0.002). Furthermore, sensitivity analysis results supported the above associations.

CONCLUSION

This study highlights the involvement of several circulating cytokines in the development ophthalmic diseases and holds potential as viable pharmacological targets for these diseases.

International society of sports nutrition position stand: coffee and sports performance

Based on review and critical analysis of the literature regarding the contents and physiological effects of coffee related to physical and cognitive performance conducted by experts in the field and selected members of the International Society of Sports Nutrition (ISSN), the following conclusions represent the official Position of the Society:(1) Coffee is a complex matrix of hundreds of compounds. These are consumed with broad variability based upon serving size, bean type (e.g. common Arabica vs. Robusta), and brew method (water temperature, roasting method, grind size, time, and equipment).(2) Coffee's constituents, including but not limited to caffeine, have neuromuscular, antioxidant, endocrine, cognitive, and metabolic (e.g. glucose disposal and vasodilation) effects that impact exercise performance and recovery.(3) Coffee's physiologic effects are influenced by dose, timing, habituation to a small degree (to coffee or caffeine), nutrigenetics, and potentially by gut microbiota differences, sex, and training status.(4) Coffee and/or its components improve performance across a temporal range of activities from reaction time, through brief power exercises, and into the aerobic time frame in most but not all studies. These broad and varied effects have been demonstrated in men (mostly) and in women, with effects that can differ from caffeine ingestion, per se. More research is needed.(5) Optimal dosing and timing are approximately two to four cups (approximately 473-946 ml or 16-32 oz.) of typical hot-brewed or reconstituted instant coffee (depending on individual sensitivity and body size), providing a caffeine equivalent of 3-6 mg/kg (among other components such as chlorogenic acids at approximately 100-400 mg per cup) 60 min prior to exercise.(6) Coffee has a history of controversy regarding side effects but is generally considered safe and beneficial for healthy, exercising individuals in the dose range above.(7) Coffee can serve as a vehicle for other dietary supplements, and it can interact with nutrients in other foods.(8) A dearth of literature exists examining coffee-specific ergogenic and recovery effects, as well as variability in the operational definition of "coffee," making conclusions more challenging than when examining caffeine in its many other forms of delivery (capsules, energy drinks, "pre-workout" powders, gum, etc.).

A scientometrics analysis of physical activity and transcranial stimulation research

BACKGROUND

The search for alternatives to improve physical performance is rising, and in recent years has been focused on the brain. No bibliometric study analyzing research on physical activity (PA) and transcranial stimulation has been found in the scientific literature. Aims: To provide an overview of the existing scientific research on PA and transcranial brain stimulation in healthy and sports participants, using a bibliometric analysis and graphic mapping of the references in the field. To do this, we analyze annual publication trends in this area, identifying the most productive and cited authors, journals and countries with the highest number of publications, and the most cited documents and keywords.

METHODS

Those publications related to this area, published in journals indexed in the web of science main collection were retrieved and analyzed using the traditional laws of bibliometrics.

RESULTS

A total of 305 documents were found. Annual publications followed an exponential growth trend (R2 = 94.2%); with A. J. Pearce (9 documents) is the most productive coauthor and M.C. Ridding, H. Theoret and M. Lassonde as the most prominent (with 5 most cited papers). The USA (67 papers) and the journal Frontiers in Human Neuroscience (12 papers) were the most productive country and journal respectively. The paper "Action anticipation and motor resonance in elite basketball players" was the most cited paper and "transcranial magnetic stimulation" was the most used keyword.

CONCLUSION

There are extensive research networks throughout the world, with the USA leading the production. Publications on the issue are of high interest in the scientific community as an exponential increase in publications over the last few years was found. The contribution of these findings is to offer a complete picture of the relationship between PA and transcranial brain stimulation in healthy individuals and athletes. Therefore, this comprehensive analysis provides fruitful information for sports researchers and policymakers to make future correct decisions about how to better design and implement training interventions in these groups of individuals.

Research Trends in the Effect of Caffeine Intake on Fat Oxidation: A Bibliometric and Visual Analysis

In the last few decades, numerous studies pertaining to research groups worldwide have investigated the effects of oral caffeine intake on fat oxidation at rest, during exercise, and after exercise. However, there is no bibliometric analysis to assess the large volume of scientific output associated with this topic. A bibliometric analysis of this topic may be used by researchers to assess the current scientific interest in the application of caffeine as a nutritional strategy to augment fat oxidation, the journals with more interest in this type of publication, and to draw international collaborations between groups working in the same area. For these reasons, the purpose of this study was to assess the research activity regarding oral caffeine intake and fat oxidation rate in the last few decades by conducting a bibliometric and visual analysis. Relevant publications from 1992 to 2022 were retrieved from the Web of Science (WoS) Core Collection database. Quantitative and qualitative variables were collected, including the number of publications and citations, H-indexes, journals of citation reports, co-authorship, co-citation, and the co-occurrence of keywords. There were 182 total publications, while the number of annual publications is saw-shaped with a modest increase of 11.3% from 2000 to 2009 to 2010 to 2019. The United States was the country with the highest number of publications (24.17% of the total number of articles), followed by the Netherlands (17.03%). According to citation analyses, the average number of citations per document is 130, although there are 21 documents that have received more than 100 citations; the most cited document reached 644 citations. These citation data support the overall relevance of this topic in the fields of nutrition and dietetics and sport sciences that when combined harbored 85.71% of all articles published in the WoS. The most productive author was Westerterp-Plantenga with 16 articles (8.79% of the total number of articles). Nutrients was the journal that published the largest number of articles on this topic (6.59% of the total number of articles). Last, there is a tendency to include keywords such as "performance", "carbohydrate", and "ergogenic aid" in the newer articles, while "obesity", "thermogenic", and "tea" are the keywords more commonly included in older documents. Although research into the role of caffeine on fat oxidation has existed since the 1970s, our analysis suggests that the scientific output associated with this topic has progressively increased since 1992, demonstrating that this is a nutritional research area with a strong foundational base of scientific evidence. Based on the findings of this bibliometric analysis, future investigation may consider focusing on the effects of sex and tolerance to caffeine to widen the assessment of the effectiveness of oral caffeine intake as a nutritional strategy to augment the use of fat as a fuel, as these terms rarely appear in the studies included in this analysis. Additionally, more translational research is necessary as the studies that investigate the effect of oral caffeine intake in ecologically valid contexts (i.e., exercise training programs for individuals with excessive adiposity) are only a minor part of the studies on this topic.

Documents Publication Evolution (1990-2022) Related to Physical Activity and Healthy Habits, a Bibliometric Review

This research aims to provide an overview of the growing number of scientific literature publications related to Physical Activity and Healthy Habits. A bibliometric analysis between 1990 and 2022 in the Web of Science was carried out, following the bibliometric analysis law, using Microsoft Excel and VosViewer Software for analysis and data processing. A total of 276 documents (262 primary studies and 14 revisions) related to the topic under study were located. The results reveal an exponential growth of scientific production by 48% between 2006 and 2022. Public Environmental Occupational Health, Kaprio, J., and the USA were the knowledge field, author, and country most productive, respectively. A great thematic diversity was found related to the most used keywords by the authors, such as "physical activity", "health habits", "exercise", and "obesity". Thus, the research related to this theme is really in an exponential phase, with great interest in the importance of physical activity and healthy habits, implying practical decisions in policies to develop programs to promote physical activity and healthy habits.

Bibliometric Analysis of Nature-Based Therapy Research

Unrestrained urbanisation and natural space loss are reducing contact with nature in today's society, producing negative consequences for people's mental and physical health and wellbeing. Nature-based therapies, such as physical activity in natural settings, forest bathing, therapeutic hiking, or experiential learning, reduce anxiety and depressive symptoms and improve the quality of life in both general and specific populations. A bibliometric analysis of research on nature-based therapies was performed by applying the traditional laws of bibliometrics (exponential growth law, Bradford's concentration law, Lotka's law, Zipf's law, etc.) to documents published in journals indexed in the Core Collection of the Web of Science (WoS). Graphical visualisation was performed using the VOSviewer software. Annual publications between 2006 and 2021 presented an exponential growth trend (R² = 91%). The International Journal of Environmental Research and Public Health (MDPI) and Urban Forestry & Urban Greening (Elsevier) were the most productive and cited journals. Ikei, Miyazaki, and Song are the most cited prolific authors. The USA and South Korea were the countries with the highest scientific production. In recent years, there has been a growing interest in adventure, nature, and forest therapies among researchers. Nature-based therapies have experienced a growing interest in recent years. Positive effects on mental, physical, and emotional health have been found in different populations and research lines, although more studies with different designs and populations are needed.

Knowledge mapping of research on the mitochondrial unfolded protein response: a bibliometric and visual analysis

Background

The mitochondrial unfolded protein response (UPR^mt) is a mitochondria stress response, which exerts a crucial role in maintaining mitochondrial proteostasis during stress. However, there is no bibliometric analyses systematically studied this field which could comprehensively review research trends, evaluate publication performances and provide future perspectives.

Methods

Articles investigating UPR^mt published between 1994 and 2021 were downloaded from the Core Collection of the Web of Science (WOS). CiteSpace and VOSviewer bibliometric software were applied for bibliometric and visual analyses.

Results

A total of 2,073 papers researching UPR^mt were retrieved. According to the published number of papers, the field of UPR^mt research has gone through its infancy (after 2000) and rapid growth (after 2021) phases. The United States and China contributed the most to UPR^mt research. Regarding the distribution of institutions, Harvard University was the most influential institution. The most prolific authors are Johan Auwerx and CM Haynes. PLoS One is the most extensive journal in the field of UPR^mt research, while the Cell Death and Differentiation journal had the greatest impact among the most-authored journals. Moreover, biochemistry/molecular biology, and cell biology are the largest subject areas. UPR^mt research is mainly categorized as UPR^mt, transcription, endoplasmic reticulum (ER) stress, lipotoxicity, mitophagy, inflammation, skeletal muscle, hypoxia, apoptosis, mitochondrial dysfunction, neurodegeneration, mitochondrial permeability transition, and integrated stress response.

Conclusions

At present, research on UPR^mt is booming. Further strengthening the cooperation and exchanges between countries, institutions, and authors in the future will surely promote the development of this field.

Breast cancer and physical activity: A bibliometric analysis

Breast cancer is a pathology suffered by millions of women worldwide, affecting the mental health, quality of life (QoL), physical functioning, cognitive functioning, and social and work life of surviving patients. Moreover, breast cancer is associated with weight gain, muscle atrophy, and weakness. Physical exercise appears to be an effective non-pharmacological treatment to improve short-term self-esteem, QoL, fatigue, and psychological factors such as depression, anxiety, happiness, and body image. The practice of physical activity is also associated with a reduction in the side effects of treatment. This bibliometric analysis analyzed the trend followed by publications on breast cancer and physical activity. The Web of Science database was used, and bibliometric laws were applied to identify the most prolific authors, the journals most involved in the field, and the countries, institutions, and keywords most used by the authors. Breast cancer and physical activity have an exponential trend in the number of publications, with Psycho-Oncology being the journal with the highest number of publications.

Fibromyalgia, Pain, and Physical Activity: A Bibliometric Analysis

Fibromyalgia (FM) is a rheumatic disease characterized by pain, fatigue, low-quality sleep, depression, anxiety, stiffness, fall risk, mood disturbance, cognitive impairment, poor physical condition, and other symptoms leading to a worse quality of life. Physical activity (PA) and exercise are effective methods to reduce FM symptoms, including pain. This study presents the first bibliometric study on FM, pain, and PA. An advanced search of the Web of Science (WoS) Core Collection database performed on this topic using was carried out traditional bibliometric laws. A total of 737 documents were found. Annual publications presented an exponentially growing trend (R2 = 85.3%). Rheumatology International, Kaisa Mannerkorpi, and the USA were the journal, co-author, and country most productive, respectively. The exponential growth of annual publications on FM, PA, and pain shows the high interest of researchers and publishers in this topic. The document "Fibromyalgia A Clinical Review" was the most cited. Moreover, Kaisa Mannerkorpi was the most prolific co-author, Rheumatology International was the most prolific journal, "Fibromyalgia: a clinical review" was the most highly cited document, and Daniel Clauw was the most cited co-author.

Variability of caffeine content in green and roasted Coffea arabica regarding the origin, post-harvest processing, and altitude, and overview of recommended daily allowance

Caffeine content is a crucial attribute of coffee. Its concentration and thus maximum cups of Coffea arabica from Africa, Asia, Central America, and South America from different altitudes of growing areas, altitude, and process using different post-harvest processing (dry, wet, and pulped natural). Our results suggest that geographical origin might affect the alkaloid concentration in C. arabica. The caffeine concentration pattern in green samples was as follows: Central America > South America > Asia > Africa. Altitude affected the concentrations, lowlands > midlands > highlands, however, not significantly. Given caffeine is thermostable, the medium roasting process did not affect the concentration of caffeine directly, but a small increase was observed. Scientific opinion on the safety of habitual caffeine consumption of up to 400 mg per day does not raise safety concerns for non-pregnant adults. A cup (7 g coffee in 120 mL of water) was used for recalculation. Results suggest that mostly highlands and midlands coffee from Africa reached levels of caffeine that might be consumed in more than 5.5 cups a day.

Bibliometric Analysis of Psychomotricity Research Trends: The Current Role of Childhood

Psychomotricity is a wide broad term, which encompasses different bodily action approaches to support children and adolescents to achieve their highest potential. A search on the Web of Science (WoS) Core Collection database was performed on this topic, using traditional bibliometric laws. Finally, 118 publications (112 articles and 6 reviews) documents were found. Annual publications presented an exponentially growing trend (R² = 84.7%). Spain was the most productive country/region worldwide. Paola Magioncalda, Matteo Martino y Víctor Arufe Giraldez were highlighted as the most prolific co-authors. "Retos Nuevas Tendencias en Educación Física, Deporte y Recreación" was the most productive journal and the "International Journal of Environmental Research and Public Health", was the second most productive; the third in the list was the most productive in the JCR ranking. Thus, research on psychomotricity is experiencing exponential growth, causing this topic to generate great interest among researchers, publishers and journals. The most cited paper was "Neurocognitive Effects of Alcohol Hangover". The author keywords that were first raised together with psychomotricity were related to rehabilitation and psychomotor development, while the current trend was focused on physical activity and early childhood education.

Knowledge mapping of students' mental health status in the COVID-19 pandemic: A bibliometric study

Objective

The purpose of this study was to investigate the international scientific output on mental health of students during COVID-19 from 2020 to 2022 through a bibliometric analysis and to explore trend and research hotspots in this field.

Methods

We searched the Web of Science Core Collection for publications and used a variety of software to analyze and visualize the data such as R, CiteSpace, VOSviewer and Scimago.

Results

A total of 2,734 publications were retrieved as of June 4, 2022, published by 3,894 institutions from 120 countries/regions. China and the United States lead in the quantity and quality of publications in this field. According to Bradford's Law, 16 journals are considered core journals in the field. Co-cited references indicate the main psychological problems of students under the epidemic revolve around anxiety, poor sleep and financial difficulty. Their behavior might also be influenced by increased internet and alcohol use.

Conclusion

Mental health of students during COVID-19 is attracting increasing attention. It is identified that the research hotspots in this field continue to revolve around emotional anxiety and unhealthy behaviors. Due to the different troubles faced by different groups under COVID-19, further exploration of the relevant factors specific for students are needed, with a hopeful view to providing ideas for intervention measures.

Nutrition and sarcopenia: Current knowledge domain and emerging trends

Objective

Non-pharmacological management like nutrient supplements has shown positive impacts on muscle mass and strength, which has burgeoned clinical and research interest internationally. The aim of this study was to analyze the current knowledge domain and emerging trends of nutrition-related research in sarcopenia and provide implications for future research and strategies to prevent or manage sarcopenia in the context of aging societies.

Materials and methods

Nutrition- and sarcopenia-related research were obtained from the Web of Science Core Collection (WoSCC) database from its inception to April 1, 2022. Performance analysis, science mapping, and thematic clustering were performed by using the software VOSviewer and R package “bibliometrix.” Bibliometric analysis (BA) guideline was applied in this study.

Results

A total of 8,110 publications were extracted and only 7,510 (92.60%) were selected for final analysis. The production trend in nutrition and sarcopenia research was promising, and 1,357 journals, 107 countries, 6,668 institutions, and 31,289 authors were identified in this field till 2021. Stable cooperation networks have formed in the field, but they are mostly divided by region and research topics. Health and sarcopenia, metabolism and nutrition, nutrition and exercise, body compositions, and physical performance were the main search themes.

Conclusions

This study provides health providers and scholars mapped out a comprehensive basic knowledge structure in the research in the field of nutrition and sarcopenia over the past 30 years. This study could help them quickly grasp research hotspots and choose future research projects.