Examining the association of habitual e-cigarette use with inflammation and endothelial dysfunction in young adults: The VAPORS-Endothelial function study.

INTRODUCTION: Acute exposure to e-cigarette aerosol has been shown to have potentially deleterious effects on the cardiovascular system. However, the cardiovascular effects of habitual e-cigarette use have not been fully elucidated. Therefore, we aimed to assess the association of habitual e-cigarette use with endothelial dysfunction and inflammation - subclinical markers known to be associated with increased cardiovascular risk. METHODS: In this cross-sectional study, we analyzed data from 46 participants (23 exclusive e-cigarette users; 23 non-users) enrolled in the VAPORS-Endothelial function study. E-cigarette users had used e-cigarettes for ≥6 consecutive months. Non-users had used e-cigarettes <5 times and had a negative urine cotinine test (<30 ng/mL). Flow-mediated dilation (FMD) and reactive hyperemia index (RHI) were used to assess endothelial dysfunction, and we assayed high-sensitivity C-reactive protein, interleukin-6, fibrinogen, p-selectin, and myeloperoxidase as serum measures of inflammation. We used multivariable linear regression to assess the association of e-cigarette use with the markers of endothelial dysfunction and inflammation. RESULTS: Of the 46 participants with mean age of 24.3 ± 4.0 years, the majority were males (78%), non-Hispanic (89%), and White (59%). Among non-users, 6 had cotinine levels <10 ng/mL while 17 had levels 10-30 ng/mL. Conversely, among e-cigarette users, the majority (14 of 23) had cotinine ≥500 ng/mL. At baseline, the systolic blood pressure was higher among e-cigarette users than non-users (p=0.011). The mean FMD was slightly lower among e-cigarette users (6.32%) compared to non-users (6.53%). However, in the adjusted analysis, current e-cigarette users did not differ significantly from non-users in their mean FMD (Coefficient=2.05; 95% CI: -2.52-6.63) or RHI (Coefficient= -0.20; 95% CI: -0.88-0.49). Similarly, the levels of inflammatory markers were generally low and did not differ between e-cigarette users and non-users. CONCLUSIONS: Our findings suggest that e-cigarette use may not be significantly associated with endothelial dysfunction and systemic inflammation in relatively young and healthy individuals. Longer term studies with larger sample sizes are needed to validate these findings.

The mediating roles of the oral microbiome in saliva and subgingival sites between e-cigarette smoking and gingival inflammation.

BACKGROUND: Electronic cigarettes (ECs) have been widely used by young individuals in the U.S. while being considered less harmful than conventional tobacco cigarettes. However, ECs have increasingly been regarded as a health risk, producing detrimental chemicals that may cause, combined with poor oral hygiene, substantial inflammation in gingival and subgingival sites. In this paper, we first report that EC smoking significantly increases the odds of gingival inflammation. Then, through mediation analysis, we seek to identify and explain the mechanism that underlies the relationship between EC smoking and gingival inflammation via the oral microbiome. METHODS: We collected saliva and subgingival samples from 75 EC users and 75 non-users between 18 and 34 years in age and profiled their microbial compositions via 16S rRNA amplicon sequencing. We conducted raw sequence data processing, denoising and taxonomic annotations using QIIME2 based on the expanded human oral microbiome database (eHOMD). We then created functional annotations (i.e., KEGG pathways) using PICRUSt2. RESULTS: We found significant increases in α-diversity for EC users and disparities in ß-diversity between EC users and non-users. We also found significant disparities between EC users and non-users in the relative abundance of 36 microbial taxa in the saliva site and 71 microbial taxa in the subgingival site. Finally, we found that 1 microbial taxon in the saliva site and 18 microbial taxa in the subgingival site significantly mediated the effects of EC smoking on gingival inflammation. The mediators on the genus level, for example, include Actinomyces, Rothia, Neisseria, and Enterococcus in the subgingival site. In addition, we report significant disparities between EC users and non-users in the relative abundance of 71 KEGG pathways in the subgingival site. CONCLUSIONS: These findings reveal that continued EC use can further increase microbial dysbiosis that may lead to periodontal disease. Our findings also suggest that continued surveillance for the effect of ECs on the oral microbiome and its transmission to oral diseases is needed.

Update on the clinical trial landscape: analysis of ClinicalTrials.gov registration data, 2000-2020.

BACKGROUND: The clinical trial landscape has evolved over the last two decades, shaped by advances in therapeutics and drug development and innovation in trial design and methods. The tracking of such changes became possible with trial registration, providing the public with a window into the massive clinical research enterprise. The ClinicalTrials.gov website was launched in 2000 by the NIH National Library of Medicine and is the largest clinical trial registry worldwide. The purpose of this analysis is to describe the composition and methodologic features of clinical trials as registered on ClinicalTrials.gov and to identify trends over time. METHODS: We analyzed data from the publicly available Clinical Trials Transformation Initiative Aggregate Analysis of ClinicalTrials.gov (AACT) database, focusing on trials (interventional studies) started between 1 January 2000 through 31 December 2020. Characteristics of design (e.g., phase, randomization, use of masking, number of treatment groups, sample size), eligibility criteria (age groups, gender), interventions, conditions, and funders (primary sponsor) were tabulated over time, by year trial started. RESULTS: There were 274,043 registered interventional studies (trials) included in the analysis. Most trials were reported as randomized (65%); single site (60%); parallel-group (56%); funded by other sources (e.g., individuals, universities, and community-based organizations) (65%); and involving drug interventions (55%). Notable trends include an increase in the proportion of registered trials without FDA-defined phases ("Phase N/A") over time, a decrease in proportion of trials that involve drugs or report treatment as a primary purpose, declining sample size and time to complete trials, and an increase in proportion of trials reporting results among completed trials. The proportion of missing registration fields has also decreased over time and more trials make protocols and other documents available. There is a current need to expand the registration fields in ClinicalTrials.gov to adapt to the evolving trial designs and reduce the number of trials categorized as "other." Observed trends may be explained by changes in trial regulations as well as expanding and evolving trial designs, interventions, and outcome types. CONCLUSIONS: Clinical trial registration has transformed how trial information is accessed, disseminated, and used. As clinical trials evolve and regulations change, trial registries, including ClinicalTrials.gov, will continue to provide a means to access and follow trials over time, thus informing future trial design and highlighting the value of this tremendous resource.

Assessment of Trends in the Design, Accrual, and Completion of Trials Registered in ClinicalTrials.gov by Sponsor Type, 2000-2019.

Importance: ClinicalTrials.gov is a valuable resource that can be used to trace the state and nature of trials. Since its launch in 2000, more than 345 000 trials have been registered. Little is known about the characteristics and trends in clinical trials over time and how they differ by sponsor type. Objective: To assess trends in clinical trials registered in ClinicalTrials.gov over time and by sponsor type. Design, Setting, and Participants: This cross-sectional study included clinical trials (interventional studies) registered in ClinicalTrials.gov from January 1, 2000, through December 31, 2019. The trials were grouped by lead sponsor: National Institutes of Health (NIH) and other US government agencies, industry, and other sources (foundations, universities, hospitals, clinics, and others). A static version of the Clinical Trials Transformation Initiative Aggregate Analysis of ClinicalTrials.gov database was downloaded on January 1, 2020, for analysis. Main Outcomes and Measures: ClinicalTrials.gov registration fields, including overall status, phase, intervention, number of sites, use of masking and randomization, sample size, and time to study completion by start year and lead sponsor (organization that provided funding or support for a clinical study). Results: A total of 245 999 clinical trials (interventional studies) were started between 2000 and 2019, of which 135 144 (54.9%) were completed. Among completed trials, 5113 (3.8%) were sponsored by the NIH or a US government agency, 48 668 (36.0%) by industry, and 81 363 (60.2%) by other sources. Most trials were single center (61.3%), randomized (65.6%), and phase 1 to 2 (35.5%) or did not have a US Food and Drug Administration-defined phase (38.4%), with fewer drug trials being conducted over time. Sample sizes were small (median, 60; interquartile range [IQR], 30-160) and diminished over time. Trial median completion times varied by lead sponsor: 3.4 years (IQR, 1.9-5.0 years) for NIH- and US government-sponsored trials, 1.2 years (IQR, 0.5-2.4 years) for industry trials, and 2.1 years (IQR, 1.1-3.7) for trials sponsored by other sources. Conclusions and Relevance: The findings suggest that the composition and design of trials changed from 2000 to 2019 and differed substantially by sponsor type. Increased funding toward larger randomized clinical trials may be warranted to inform clinical decision-making and guide future research.

Characteristics and trends of clinical trials funded by the National Institutes of Health between 2005 and 2015.

Background The National Institutes of Health is one of the largest biomedical research agencies in the world. Clinical trials are an important component of National Institutes of Health research efforts. Given the recent updates in National Institutes of Health trial reporting requirements, more information regarding the current state of National Institutes of Health-funded clinical trials is warranted. The objective of this analysis was to describe characteristics and trends of clinical trials funded by the National Institutes of Health over time and by Institutes and Centers of the National Institutes of Health. Methods Interventional studies funded by the National Institutes of Health and registered in ClinicalTrials.gov between 2005 and 2015 were included in the analysis. Trials were identified from the 27 March 2016 Clinical Trials Transformation Initiative Aggregate Analysis of ClinicalTrials.gov database. A descriptive analysis of trials by year and National Institutes of Health Institute/Center was performed. Results There were 12,987 National Institutes of Health-funded clinical trials registered between 2005 and 2015. There were 1,580, 1,116, and 930 trials registered in 2005, 2010, and 2015, respectively. The majority were early-development trials (phases 0, 1, or 2; 53%), randomized (61%), and single-center (63%). Trial demographics have remained unchanged over time. Median trial sample size was 64 (interquartile range 29-192) with 10% of trials enrolling ≥500 participants. Most trials were completed within 5 years of enrollment start (69%). Trial characteristics varied considerably across National Institutes of Health Institutes and Centers. Results were reported under the assumptions that most National Institutes of Health-funded trials are registered in ClinicalTrials.gov and that trials are being registered completely and accurately. Conclusion In conclusion, there has been a decline in the number of trials being funded over time, explained in part by a relatively constant budget, increases in trial costs, or other factors that cannot be quantified. National Institutes of Health-funded trials are relatively small and tend to be single-centered. There are substantial differences in the number and types of trials done by Institutes and Centers within the National Institutes of Health.

Gender indexing in publications of clinical trials: 1991-2008.

BACKGROUND: In 1993 Congress passed the NIH Revitalization Act, which instructed the Director of the NIH to ensure that phase III clinical trials are 'designed and carried out in a manner sufficient to provide for a valid analysis of whether the variables being studied in the trial affect females or members of minority groups, as the case may be, differently than other subjects in the trial.' PURPOSE: The purpose of this article is to track the PubMed indexing of gender in clinical trial publications since 1991 with a view toward assessing the impact of the legislation on the number of gender specific trials. METHODS: We searched PubMed for full-length publications from years 1991 to 2008 of research on humans indexed as publication type 'clinical trial', 'randomized clinical trial' and multicenter randomized trial ('multicenter study' AND 'randomized clinical trial'), and counted the number of trials indexed as male-only, female-only, male and female, and gender unknown in PubMed. RESULTS: The majority of trial publications were indexed in PubMed as including both genders. The proportion of publications indexed as including both genders has increased while the number of publications not indexed with respect to gender and the number of publications indexed as male-only have decreased. In 2005, approximately 13% of NIH expenditures were for female specific or related research compared to 6% for male specific or related research. LIMITATIONS: The proportion of clinical trial publications that were indexed in PubMed as including females began to increase before the legislation so it is difficult to conclude that changes in the number of female-only or male-only trials are due to the legislation. PubMed listings do not include gender enrollment, so female and male enrollment totals could not be compared. CONCLUSIONS: The NIH policy should be rewritten to be made gender neutral to bring it in line with the principle of justice as embodied in the Belmont Report.