A critique of recent hypotheses on oral (and lung) cancer induced by water pipe (hookah, shisha, narghile) tobacco smoking

Water pipe smoking and stroke: A systematic review and meta-analysis

OBJECTIVE

Despite the damaging effects of water pipe on physical health, there is little information about the potential harmful effects of this tobacco on stroke. This study aims to investigate the relationship between water pipe smoking and stroke.

METHOD

A systematic review was conducted including Ovid SP, Embase, Pubmed, Web of Science, Scopus, and Google Scholar databases with focus on cohort, case-control, and cross-sectional studies. We reviewed all studies reporting on water pipe smoking and stroke. The funnel plot and the Egger regression test were used to assess publication bias.

RESULTS

In the four eligible studies, there were a total of 2759 participants that 555 patients had at least once experienced stroke. Meta-analysis revealed positive association between water pipe smoking and stroke with pooled adjusted OR 2.79 (95% CI: 1.74-3.84;I 2 = 0 , p = . 741 ${I^2}\; = \;\;0,{\mathrm{\;}}p\;\; = {\mathrm{\;\;}}.741$ ) and the funnel plot shows asymmetry publication bias.

CONCLUSIONS

We found a higher effect of water pipe smoking on stroke compared to cigarette smoking and concluded that water pipe increases the risk of stroke by 2.79. Hence, because most of the water pipe consumer society is young, especially women, policies and decisions need to be taken to control the supply of this tobacco to the market and more provide education on the health problem of water pipe smoking.

IMPLICATIONS

This study provides a higher effect of water pipe smoking on stroke. Physicians and researchers who intend to study in the field of stroke should better examine the effects of water pipe (including time of use, dose-response, long-term effects, and risk factors) on stroke.

Cytotoxic and Genotoxic Effects of Waterpipe on Oral Health Status: Systematic review and meta-analysis

This systematic review and meta-analysis aimed to assess the cytotoxic and genotoxic impacts of waterpipe smoking on oral health. The databases MEDLINE, Cochrane Library and Dimensions were searched to find studies evaluating whether waterpipe smokers exhibited any cytotoxic or genotoxic effects on their oral cells compared to non-smokers, with regard to mouth neoplasms. Particularly, changes in DNA methylation and p53 expression were assessed. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were adopted for the systematic review. Review Manager was utilised for statistical analysis with a significance level at P <0.05. To assess the grades of the included articles, a risk of bias analysis was summarised. A forest plot, including some of the included articles included, was created regarding the different grades. A total of 20 studies were included in this review. The results showed that waterpipe smoking has cytotoxic and genotoxic effects on oral cells, with a risk difference of 0.16. Although the published articles are few in number, all confirm the devastating effects of waterpipe smoking related to the carcinogenicity. Waterpipe smoking is harmful to oral health. It causes a series of detrimental cellular and genetic modifications such as acanthosis, epithelial dysplasia and hyperparakeratosis. In addition, waterpipe smoke contains several carcinogenic compounds. As it releases many harmful organic compounds, waterpipe smoking increases the incidence of oral cancer.

Salivary Biomarkers in Lung Cancer

A very low percentage of lung cancer (LC) cases are discovered at an early and treatable stage of the disease, leading to an abysmally low 5-year survival rate. This underscores the immediate necessity for improved diagnostic, prognostic, and predictive biomarkers for LC. Biopsied lung tissue, blood, and plasma are common sources used for LC diagnosis and monitoring of the disease. A growing number of studies have reported saliva to be a useful biological sample for early and noninvasive detection of oral and systemic diseases. Nevertheless, salivary biomarker discovery remains underresearched. Here, we have compiled the available literature to provide an overview of the current understanding of salivary markers for LC detection and provided perspectives for future clinical significance. Valuable markers with diagnostic and prognostic potentials in LC have been discovered in saliva, including metabolic (catalase activity, triene conjugates, and Schiff bases), inflammatory (interleukin 10, C-X-C motif chemokine ligand 10), proteomic (haptoglobin, zinc-α-2-glycoprotein, and calprotectin), genomic (epidermal growth factor receptor), and microbial candidates (Veillonella and Streptococcus). In combination, with each other and with other established screening methods, these salivary markers could be useful for improving early detection of the disease and ultimately improve the survival odds of LC patients. The existing literature suggests that saliva is a promising biological sample for identification and validation of biomarkers in LC, but how saliva can be utilized most effectively in a clinical setting for LC management is still under investigation.

Tobacco-product usage as a risk factor for dental implants

The oral cavities of tobacco smokers and users of smokeless tobacco products are exposed to high concentrations of nicotine. A limited number of animal studies have assessed the effect of nicotine on osseointegration. Results from experimental studies have reported a statistically significant decrease, at 4 weeks of follow-up, in bone-to-implant contact among rats exposed to nicotine compared with unexposed rats. Nicotine increases the production of inflammatory cytokines (such as interleukin-6 and tumor necrosis factor-alpha) by osteoblasts. Waterpipe, pipe, and cigarette smokers are at increased risk of developing oral cancer, periodontal disease, and alveolar bone loss. One explanation for this is that smokers (regardless of the type of tobacco product) are exposed to similar chemicals, such as nicotine, tar, oxidants, polyaromatic hydrocarbons, and carbon monoxide. Moreover, raised levels of proinflammatory cytokines have been identified in the gingival crevicular fluid of cigarette smokers with peri-implant diseases. Therefore, it is hypothesized that nicotine and chemicals in tobacco smoke induce a state of oxidative stress in peri-implant tissues (gingiva and alveolar bone), thereby increasing the likelihood of peri-implant disease development via an inflammatory response, which if left uncontrolled, will result in implant failure/loss. In this regard, tobacco smoking (including cigarettes, waterpipe, and pipe) is a significant risk factor for peri-implant diseases. The impact of vaping electronic cigarettes using nicotine-containing e-juices remains unknown. Habitual use of smokeless tobacco products is associated with oral inflammatory conditions, such as oral precancer, cancer, and periodontal disease. However, the effect of habitual use of smokeless tobacco products on the success and survival of dental implants remains undocumented.

Dysbiosis of the Salivary Microbiome Is Associated With Non-smoking Female Lung Cancer and Correlated With Immunocytochemistry Markers

Background: Association between oral bacteria and increased risk of lung cancer have been reported in several previous studies, however, the potential association between salivary microbiome and lung cancer in non-smoking women have not been evaluated. There is also no report on the relationship between immunocytochemistry markers and salivary microbiota.

Method: In this study, we assessed the salivary microbiome of 75 non-smoking female lung cancer patients and 172 matched healthy individuals using 16S rRNA gene amplicon sequencing. We also calculated the Spearman's rank correlation coefficient between salivary microbiota and three immunohistochemical markers (TTF-1, Napsin A and CK7).

Result: We analyzed the salivary microbiota of 247 subjects and found that non-smoking female lung cancer patients exhibited oral microbial dysbiosis. There was significantly lower microbial diversity and richness in lung cancer patients when compared to the control group (Shannon index, P < 0.01; Ace index, P < 0.0001). Based on the analysis of similarities, the composition of the microbiota in lung cancer patients also differed from that of the control group (r = 0.454, P < 0.001, unweighted UniFrac; r = 0.113, P < 0.01, weighted UniFrac). The bacterial genera Sphingomonas (P < 0.05) and Blastomonas (P < 0.0001) were relatively higher in non-smoking female lung cancer patients, whereas Acinetobacter (P < 0.001) and Streptococcus (P < 0.01) were higher in controls. Based on Spearman's correlation analysis, a significantly positive correlation can be observed between CK7 and Enterobacteriaceae (r = 0.223, P < 0.05). At the same time, Napsin A was positively associated with genera Blastomonas (r = 0.251, P < 0.05). TTF-1 exhibited a significantly positive correlation with Enterobacteriaceae (r = 0.262, P < 0.05). Functional analysis from inferred metagenomes indicated that oral microbiome in non-smoking female lung cancer patients were related to cancer pathways, p53 signaling pathway, apoptosis and tuberculosis.

Conclusions: The study identified distinct salivary microbiome profiles in non-smoking female lung cancer patients, revealed potential correlations between salivary microbiome and immunocytochemistry markers used in clinical diagnostics, and provided proof that salivary microbiota can be an informative source for discovering non-invasive lung cancer biomarkers.

Toxicological impact of waterpipe smoking and flavorings in the oral cavity and respiratory system

Waterpipe smoking (WS), an emerging trend has major health concerns. It is prevalent worldwide as a recreational activity both indoors and outdoors. The aim of this review was to assess the impact of waterpipe smoke on the oral and respiratory system (oral cavity and pulmonary tissues). A number of studies have shown that periodontal health status is compromised in waterpipe smokers when compared with nonsmokers. Some studies have associated WS with oral premalignant and malignant lesions; however, due to the poor quality of these studies, the presented outcomes should be interpreted with caution. Although cigarette smoking has been considered as a potential risk factor for dental caries; there are no studies in indexed literature that have shown an association to exist between dental caries and WS. Inhaled waterpipe smoke imposes oxidative stress and inflammatory responses and compromises the ventilatory capacity of the lungs and may lead to an increased risk of decline in lung function. WS may cause oral and pulmonary diseases, such as periodontal disease and chronic obstructive airway disease, respectively. The association between WS and development of dental caries and oral pre-cancer and their relationships with chronic airways disease requires investigations. This review discusses the current evidence of waterpipe smoke effects on the oral health and respiratory system based on basic and clinical science and provides future directions for research and regulatory science on how WS can affect the oral cavity and the respiratory/pulmonary system.

Use & Misuse of Water-filtered Tobacco Smoking Pipes in the World. Consequences for Public Health, Research & Research Ethics

BACKGROUND

The traditional definition of an "epidemic" has been revisited by antismoking researchers. After 400 years, Doctors would have realized that one aspect of an ancient cultural daily practice of Asian and African societies was in fact a "global "epidemic"". This needed further investigation particularly if one keeps in his mind the health aspects surrounding barbecues.

METHOD

Here, up-to-date biomedical results are dialectically confronted with anthropological findings, hence in real life, in order to highlight the extent of the global confusion: from the new definition of an "epidemic" and "prevalence" to the myth of "nicotine "addiction"" and other themes in relation to water filtered tobacco smoking pipes (WFTSPs).

RESULTS

We found that over the last decade, many publications, -particularly reviews, "meta-analyses" and "systematic reviews"- on (WFTSPs), have actually contributed to fuelling the greatest mix-up ever witnessed in biomedical research. One main reason for such a situation has been the absolute lack of critical analysis of the available literature and the uncritical use of citations (one seriously flawed review has been cited up to 200 times). Another main reason has been to take as granted a biased smoking robot designed at the US American of Beirut whose measured yields of toxic chemicals may differ dozens of times from others' based on the same "protocol". We also found that, for more than one decade, two other main methodological problems are: 1) the long-lived unwillingness to distinguish between use and misuse; 2) the consistent unethical rejection of biomedical negative results which, interestingly, are quantitatively and qualitatively much more instructive than the positive ones.

CONCLUSION

the great majority of WFTSP toxicity studies have actually measured, voluntarily or not, their misuse aspects, not the use in itself. This is in contradiction with both the harm reduction and public health doctrines. The publication of negative results should be encouraged instead of being stifled.

Harmful effects of shisha: literature review

Tobacco is a preventable cause of morbidity and mortality across the world. A recently infamous way of smoking tobacco is shisha. Shisha smoking is also known as water pipe, hookah and Narghile smoking. The percentage of shisha smokers is on the rise rapidly spanning the globe. A literature review was conducted to identify all evidence on the epidemiological variations and health effects of shisha smoking. “Pub med” is used as a searching tool to identify all relevant empirical studies conducted worldwide. A qualitative overview of evidence is presented.

Exposure to Shisha smoking is significantly associated with low infant weight, heart rate variations, hyperglycemia and hypertriglyceridemia. Increased risk of carcinoma is also leagued with it including carcinomas of the pancreas and lung being at the forefront. In conclusion, this review identifies grounds of several adverse conditions being associated with the habit of shisha smoking. It also evaluates the relevant epidemiological variations around the globe. The review culminates in the importance of enlightening shisha smokers regarding its deleterious effects.

To what extent should waterpipe tobacco smoking become a public health priority?

BACKGROUND

Waterpipe tobacco smoking (WTS) popularity is increasing world-wide, and health effects are emerging in the light of evidence that WTS is perceived by users as less harmful than cigarette smoking. However, there remains a paucity of available evidence from which to draw firm conclusions about its public health significance.

AIMS

This narrative review aims to summarize WTS literature to date to inform tobacco control specialists and health-care professionals about this phenomenon and help them to assess whether or not WTS should become a public health priority.

METHODS

Standard electronic databases as well as conference proceedings and personal libraries were searched in English, French and Arabic with inclusive terminology for the variety of names given to WTS.

FINDINGS

Waterpipe smoke contains significant levels of toxins, some of which are known to be carcinogenic to humans. Recent epidemiological trends have established an increasing prevalence of WTS in the Middle East and the United States, particularly among adolescents. It is used commonly across multiple ethnicities and both genders with less of a social gradient than cigarette smoking. Attitudes and beliefs have been researched widely and several reasons for believing it is less harmful than cigarette smoking include water filtration and social acceptability. A wide range of diseases have been associated with WTS, but research in this area is relatively underdeveloped and a better evidence base is needed. Worryingly, the waterpipe industry, including waterpipe cafes, operates in an almost completely unregulated market and employs deceptive marketing techniques to attract new users.

CONCLUSIONS

Waterpipe tobacco smoking (WTS) appears to be on the increase, especially among younger users, and therefore represents a potential public health concern. While legislators should consider enforcing and extending existing tobacco laws to a growing WTS industry, further research is required to fill gaps in the literature and provide evidence-based interventions for tobacco control specialists and health-care professionals.

Waterpipe smoking, oral cancer and other oral health effects

DATA SOURCES

MEDLINE, EMBASE and ISI the Web of Science.

STUDY SELECTION

Articles in any language that assessed the association between water pipe smoking and any health outcome. Included studies were cohort, case-control and cross-sectional. Studies were excluded if they looked at physiological outcomes, non-tobacco pipe use, or didn't differentiate between this and other smoking habits.

DATA EXTRACTION AND SYNTHESIS

Data were abstracted independently by two reviewers using a standardised screening guide and GRADE used to evaluate study quality. The I(2) statistic was used to measure heterogeneity. Odds ratios for the effect of pipe smoking on lung, bladder, oesophageal and nasopharyngeal cancer, oral dysplasia, pregnancy outcomes, periodontal disease, hepatitis, respiratory illness and infertility were extracted.

RESULTS

Twenty-three studies were included. Based on the available evidence, waterpipe tobacco smoking was significantly associated with lung cancer, respiratory illness, low birth-weight and periodontal disease. It was not significantly associated with bladder, nasopharyngeal and oesophageal cancers, neither with oral dysplasia or infertility, but the confidence Intervals (CIs) did not exclude important associations. Smoking a waterpipe in groups was not significantly associated with hepatitis C infection. The overall quality of evidence varied from very low to low.

CONCLUSIONS

The evidence from very low to low quality studies is that waterpipe tobacco smoking is possibly associated with a number of deleterious health outcomes including lung cancer, respiratory illness, low birth-weight and periodontal disease.

Assessment of narghile (shisha, hookah) smokers' actual exposure to toxic chemicals requires further sound studies

Tobacco smoking is hazardous for health. However, not all forms of tobacco use entail the same risks and the latter should be studied and compared in a sound realistic way. Smoking machines for cigarettes (which are consumed in a few minutes) were early designed as a tool to evaluate the actual intake of toxic substances ('toxicants') by smokers. However, the yields (tar, nicotine, CO, etc.) provided by such machines poorly reflect the actual human smoking behaviour known to depend on numerous factors (anxiety, emotions, anthropological situation, etc.). In the case of narghile smoking, the problems are even more complex, particularly because of the much longer duration of a session. A recent study from the US-American University of Beirut was based on a field smoking topography and claimed consistency with a laboratory smoking machine. We offer a point by point critical analysis of such methods on which most of the 'waterpipe' antismoking literature since 2002 is based.