ABSTRACT
BACKGROUND: Periodontal disease and lung function impairment were found to be associated with low-grade systemic or local inflammation, and it might be that gingival/periodontal inflammation triggers lung function due to systemic inflammation or the transfer of oral bacteria or its components to the lung. A recent observational study in non-smoking subjects showed that lung volumes and flow rates were significantly reduced by 71-185 ml for severe gingivitis regardless of the adjustment for potential confounders. The result did not show any confounding by smoking, and the association between gingivitis and lower lung function was not modified by systemic inflammation. The designed interventional trial primarily aims to test the hypothesis that gingivitis reduction by optimized daily oral hygiene, professional tooth cleaning and antibacterial chlorhexidine (CHX)-containing mouth rinse improves lung function in terms of forced vital capacity (FVC) by at least 2%. The secondary objective will test the hypothesis that gingivitis reduction improves forced expiratory volume in 1 s (FEV1) and forced expiratory flow at 25-75% of the pulmonary volume (FEF25-75) by at least 2%. Furthermore, the influence of the oral microbiome will be taken into account. METHODS: The study has to include 120 non-smoking subjects aged between 18 and 30 years with biofilm-induced gingivitis. The chosen "waiting control group design" will compare the immediate intervention group with the delayed intervention group, which serves as a control group. Dental and gingival status, lung function and oral microbiome will be recorded. The intensified preventive intervention-professional tooth cleaning, one-stage full-mouth disinfection with CHX and safeguarding an optimal daily oral hygiene by each subject-cannot be blinded, but the outcome measurement in terms of lung function tests is blind. DISCUSSION: This proposed multidisciplinary study has several strengths. Only one previous intervention study with patients with severe periodontitis (mostly smokers) has been performed. It is novel to include non-smoking subjects with mild and potentially reversible oral inflammation. Furthermore, this research is innovative, because it includes evidence-based interventions for gingivitis reduction, standardized measures of the outcome on lung function and oral microbiome and combines expertise from dentistry, lung physiology, oral microbiology and epidemiology/statistical modelling. TRIAL REGISTRATION: German Clinical Trial Register DRKS00028176. Registered on February 2022.
Subject(s)
Gingivitis , Oral Hygiene , Humans , Adolescent , Young Adult , Adult , Chlorhexidine/adverse effects , Gingivitis/diagnosis , Gingivitis/prevention & control , Inflammation , Lung , Mouthwashes/adverse effectsABSTRACT
BACKGROUND: Increasing numbers of epidemiological studies are investigating the association between outdoor greenery and various health outcomes. However, in the case of indoor plants, although experimental studies seem relatively abundant, epidemiological studies remain scarce, and research considering the mental health effects is even more limited. Thus, we aim to identify and summarise the relevant epidemiological studies on indoor plant exposure and mental health via this scoping review, thereby presenting the current state of knowledge and research niches. METHODS: PubMed and PsycINFO were systematically searched for epidemiological studies on indoor plant exposure and mental health, including mental and behavioural disorders, quality of life, and cognitive function. The publication period was from the inception of these two databases to 22nd June 2022. We extracted information on exposure to indoor plants and mental health-related outcomes from the relevant studies. RESULTS: The systematic search yielded 1186 unique results. Six studies met the inclusion criteria and were finally included in this scoping review. All included studies were Europe-based cross-sectional studies on mental and behavioural disorders. One study was conducted in 2015 and investigated the office environment, whereas the other five were conducted during the COVID-19 pandemic and focused on the home environment. Despite considerable heterogeneity in outcome assessments and indoor plant exposure metrics, all six studies generally reported beneficial associations between having indoor plants and mental health, such as reducing stress, depressive symptoms, and negative emotions. CONCLUSIONS: Epidemiological evidence on exposure to indoor plants and mental health is currently limited. In general, favourable effects of indoor plants are supported, although most relevant studies were conducted in the context of COVID-19. Before conducting more studies to explore the associations, data collection methods must be refined with more elaborate designs that allow for the measurement of more comprehensive metrics of indoor plants. REGISTRATION: Open Science Framework, osf.io/5xr6b.
Subject(s)
COVID-19 , Mental Health , Humans , Pandemics , Quality of Life , COVID-19/epidemiology , Cross-Sectional Studies , Epidemiologic StudiesABSTRACT
AIM: The aim of this review is to identify epidemiological studies on the risk of infection with SARS-CoV-2 during travel by train and bus and to critically evaluate them also with regard to extrapolating the findings to the German situation. METHODS: Systematic review based on searching two electronic databases (PubMed, Web of Science) according to the principle of Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) for epidemiological studies on SARS-CoV-2 or COVID-19 and travel by train or bus. RESULTS: Searches of the two electronic databases yielded 746 publications. Of these, 55 met the selection criteria and were included in the full-text search. Finally, 5 original publications were used to answer the question about SARS-CoV-2 infections related to long-distance travel by train and 4 related to bus travel. The studies were very heterogeneous and referred almost exclusively to long-distance travel in China. They consistently showed a risk of infection when infected persons travelled in the same train, car or bus without mouth-to-nose (MNB) coverage. The risk was not limited to those sitting in close proximity to an infected fellow traveler. Despite all the differences between travel by train and bus in China and Germany, there is no fundamental doubt that the reported results from China can also be extrapolated to Germany in qualitative terms. However, it must be taken into account that the results of the three key publications predominantly included the period before the lockdown in China without the strict use of MNB. Thus, the question remains whether the results would be similar under current conditions with MNB and more virulent viral mutations. No single study was found related to infection when using public transportation. CONCLUSIONS: There are several lines of evidence that travel by train is associated with a significantly lower risk of infection compared with the risk of infection in the home environment. Due to a lack of observational data, one will need to model the risk of infection for long-distance travel by bus and use of local public transport based on air exchange in the passenger compartment, travel duration, distance from other passengers, and ultimately passenger density.