Pulmonary Abnormalities in Young, Light-Use Waterpipe (Hookah) Smokers

Medical Trainees' Knowledge and Attitudes Towards Electronic Cigarettes and Hookah: A Multinational Survey Study

BACKGROUND

The rising prevalence of electronic cigarette (e-cigarette) and hookah use among youth raises questions about medical trainees' views of these products. We aimed to investigate medical trainees' knowledge and attitudes toward e-cigarette and hookah use.

METHODS

We used data from a large cross-sectional survey of medical trainees in Brazil, the United States, and India. We investigated demographic and mental health aspects, history of e-cigarettes and tobacco use, knowledge and attitudes toward e-cigarettes and hookah, and sources of information on e-cigarettes and hookah. Although all medical trainees were eligible for the original study, only senior students and physicians-in-training were included in the present analysis.

RESULTS

Of 2,036 senior students and physicians-in-training, 27.4% believed e-cigarette use to be less harmful than tobacco smoking. As for hookah use, 14.9% believed it posed a lower risk than cigarettes. More than a third of trainees did not acknowledge the risks of passive e-cigarette use (42.9%) or hookah smoking (35.1%). Also, 32.4% endorsed e-cigarettes to quit smoking, whereas 22.5% felt ill equipped to discuss these tobacco products with patients. Fewer than half recalled attending lectures on these topics, and their most common sources of information were social media (54.5%), Google (40.8%), and friends and relatives (40.3%).

CONCLUSIONS

Medical trainees often reported incorrect or biased perceptions of e-cigarettes and hookah, resorted to unreliable sources of information, and lacked the confidence to discuss the topic with patients. An expanded curriculum emphasis on e-cigarette and hookah use might be necessary because failing to address these educational gaps could risk years of efforts against smoking normalization.

Standards for the care of people with cystic fibrosis; establishing and maintaining health

This is the second in a series of four papers updating the European Cystic Fibrosis Society (ECFS) standards for the care of people with CF. This paper focuses on establishing and maintaining health. The guidance is produced using an evidence-based framework and with wide stakeholder engagement, including people from the CF community. Authors provided a narrative description of their topic and statements, which were more directive. These statements were reviewed by a Delphi exercise, achieving good levels of agreement from a wide group for all statements. This guidance reinforces the importance of a multi-disciplinary CF team, but also describes developing models of care including virtual consultations. The framework for health is reinforced, including the need for a physically active lifestyle and the strict avoidance of all recreational inhalations, including e-cigarettes. Progress with cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapy is reviewed, including emerging adverse events and advice for dose reduction and interruption. This paper contains guidance that is pertinent to all people with CF regardless of age and eligibility for and access to modulator therapy.

Increased airway resistance among exclusive waterpipe smokers detected using impulse oscillometry

INTRODUCTION

Waterpipe smoking is increasing in popularity, yet the evidence implicating waterpipe smoking in lung disease is limited. We hypothesized that impulse oscillometry (IOS) would detect airway abnormalities in waterpipe smokers (WPS).

METHODS

We studied 210 participants, 40 years or older, from the community, of whom 92 were exclusive WPS and 118 were never-smokers. Waterpipe smoking history was assessed using a validated questionnaire. All participants underwent spirometry, and IOS and absolute and percentage predicted results (for age, sex, height, and weight) were compared between WPS and nonsmokers. The association of IOS parameters with waterpipe smoking duration and extent (waterpipe smoked/day * smoking duration) was evaluated using linear regression.

RESULTS

WPS smoked on average 1.8 ± 1.2 waterpipes/day, over an average duration of 23.3 ± 39.8 years. WPS and nonsmokers were largely asymptomatic and had similar age, body mass index, sex distribution, and spirometric values. Nevertheless, WPS had higher IOS measured resistance at 5Hz compared to nonsmokers, (0.53 ± 0.2 vs. 0.48 ± 0.2 kPa/L/s, P = 0.03) and higher percentage-predicted resistance (124.5 ± 36.3 vs. 115.7% ± 35.6%, P = 0.04). Waterpipe smoking duration was also associated with resistance (β = 0.04 kPa/L/s/year, P = 0.01) and with percentage-predicted resistance (β = 0.05/year, P = 0.02). Waterpipe smoking extent was associated with resistance (β = 0.009 kPa/L/s/waterpipe-year, P = 0.04), while the association with percentage-predicted resistance was near significance (β = 0.009/waterpipe-year, P = 0.07).

CONCLUSIONS

Waterpipe smoking is associated with increased airway resistance assessed by IOS but not by spirometry in largely asymptomatic individuals from the community.

Waterpipe smoking: Results from a population-based study in Qatar

INTRODUCTION

Waterpipe smoking is common in the Eastern Mediterranean Region and is becoming more prevalent in Qatar. To better plan waterpipe smoking control strategies we aimed to: 1) determine the prevalence of waterpipe smoking and explore its patterns in Qatar; 2) describe the knowledge, attitudes, and practices related to smoking behaviors; 3) recognize locations of waterpipe smoking and symptoms experienced during waterpipe sessions; and 4) evaluate the frequency of waterpipe smoking and the initiation age.

METHODS

We analyzed the data of a 7921 population-based survey of adults aged ≥18 years (nationals and expatriates), conducted in Qatar between March and December 2019. Out of 7105 surveys collected, 6904 were complete and included in the analysis.

RESULTS

Of the 6904, 570 (8.3%; 95% CI: 7.7–9.0) were waterpipe tobacco smokers, 425 (10.6%) males and 145 (5.1%) females. The highest prevalence of waterpipe smoking was reported among people aged 18–24 years (10.6%). Of the 575 waterpipe smokers, 56.3% (n=324) were exclusive waterpipe smokers. Use of other tobacco products among waterpipe smokers was higher among Qataris (52.3%) than expatriates (37.7%). Waterpipe cafés were the most common location for waterpipe smoking, however, females preferred restaurants; 83.3% reported that waterpipe smoking is harmful, while 39.3% considered that it is less harmful than cigarette smoking.

CONCLUSIONS

Waterpipe smoking prevalence is considerably high in Qatar, the second form of tobacco used. The formulation of new policies and enforcement of regulatory restrictions on waterpipe smoking are essential to reduce its uptake. Expansion in tobacco cessation services for women and poly-tobacco users is needed.

The adverse health effects of waterpipe smoking in adolescents and young adults: A narrative review

Waterpipe (WP) smoking has rapidly grown in popularity in the United States and other Western countries with the fastest uptake among younger individuals. This growth has been encouraged by the misperception that WP smoke is harmless or less harmful than cigarette smoke. To better understand how WP affects the health of young people, we conducted a narrative review of the literature focusing on the adverse health effects of WP smoking in adolescents and younger adults. We searched scientific literature databases including PubMed, MEDLINE, EMBASE, and ISI Web and selected papers that met the inclusion criteria. Sixty-three papers met the inclusion criteria and were selected for review. Data were abstracted from the selected papers into a standardized table. The evidence demonstrates that WP smoking can cause acute lung infection and injury, and carbon monoxide (CO) poisoning, in adolescents and young adults. It is also associated with adverse subclinical effects in this sub-population, including oral and systemic genotoxicity, lung function decline, and the alteration of vascular and hemodynamic functions. Limited evidence that is available indicates associations with psychological and neurological effects and asthma. No identified publications examined the association between WP use and type 2 diabetes, a condition that is associated with cigarette smoking among young people. WP smoking by younger individuals can result in their hospitalization due to systemic CO poisoning and acute lung disease, and induce subclinical adverse effects in the oral cavity, pulmonary system, and in circulation, that are involved in the pathogenesis of local and systemic chronic diseases.

Exosomal microRNAs are novel circulating biomarkers in cigarette, waterpipe smokers, E-cigarette users and dual smokers

BACKGROUND

Electronic cigarettes (e-cigs) vaping, cigarette smoke, and waterpipe tobacco smoking are associated with various cardiopulmonary diseases. microRNAs are present in higher concentration in exosomes that play an important role in various physiological and pathological functions. We hypothesized that the non-coding RNAs transcript may serve as susceptibility to disease biomarkers by smoking and vaping.

METHODS

Plasma exosomes/EVs from cigarette smokers, waterpipe smokers and dual smokers (cigarette and waterpipe) were characterized for their size, morphology and TEM, Nanosight and immunoblot analysis. Exosomal RNA was used for small RNA library preparation and the library was quantified using the High Sensitivity DNA Analysis on the Agilent 2100 Bioanalyzer system and sequenced using the Illumina NextSeq 500 and were converted to fastq format for mapping genes.

RESULTS

Enrichment of various non-coding RNAs that include microRNAs, tRNAs, piRNAs, snoRNAs, snRNAs, Mt-tRNAs, and other biotypes are shown in exosomes. A comprehensive differential expression analysis of miRNAs, tRNAs and piRNAs showed significant changes across different pairwise comparisons. The seven microRNAs that were common and differentially expressed of when all the smoking and vaping groups were compared with non-smokers (NS) are hsa-let-7a-5p, hsa-miR-21-5p, hsa-miR-29b-3p, hsa-let-7f-5p, hsa-miR-143-3p, hsa-miR-30a-5p and hsa-let-7i-5p. The e-cig vs. NS group has differentially expressed 5 microRNAs (hsa-miR-224-5p, hsa-miR-193b-3p, hsa-miR-30e-5p, hsa-miR-423-3p, hsa-miR-365a-3p, and hsa-miR-365b-3p), which are not expressed in other three groups. Gene set enrichment analysis of microRNAs showed significant changes in the top six enriched functions that consisted of biological pathway, biological process, molecular function, cellular component, site of expression and transcription factor in all the groups. Further, the pairwise comparison of tRNAs and piRNA in all these groups revealed significant changes in their expressions.

CONCLUSIONS

Plasma exosomes of cigarette smokers, waterpipe smokers, e-cig users and dual smokers have common differential expression of microRNAs which may serve to distinguish smoking and vaping subjects from NS. Among them has-let-7a-5p has high sensitivity and specificity to distinguish NS with the rest of the users, using ROC curve analysis. These findings will pave the way for the utilizing the potential of exosomes/miRNAs as a novel theranostic agents in lung injury and disease caused by tobacco smoking and vaping.

The effects of hookah/waterpipe smoking on general health and the cardiovascular system

Hookah or waterpipe smoking or use is an emerging trend in the US population, especially among the youth. The misperception of hookah being less harmful than cigarettes and the availability of different but "appealing" flavors are considered among the main reasons for this trend. Hookah users however are exposed to many of the same toxic compounds/by-products as cigarette users, but at dramatically higher levels, which might lead to more severe negative health effects. In fact, hookah users are at risks of infections, cancers, lung disease, and other medical conditions. Moreover, because of the overlapping toxicant/chemical profile to conventional cigarettes, hookah smoke effects on the cardiovascular system are thought to be comparable to those of conventional cigarettes. A major source of tobacco addiction is nicotine, whose levels in hookah are extremely variable as they depend on the type of tobacco used. Taken together, in this review of literature, we will provide insights on the negative health effects of hookah in general, with a focus on what is known regarding its impact on the cardiovascular system.

Respiratory health and quality of life in young exclusive, habitual smokers - a comparison of waterpipe smokers, cigarette smokers and non-smokers

Purpose

Waterpipe (WP) use has become a global trend in young populations. However, there are few well-controlled studies focusing specifically on the chronic effects of exclusive WP use on young adults’ respiratory health. We sought to compare in young adults the burden of respiratory symptoms in regular WP smokers (WPS) relative to regular cigarette smokers (CS, positive controls) and non-smokers (negative controls); and to evaluate differences in health-related quality of life between the three groups.

Method

We implemented a cross-sectional survey in college campuses across four countries (Egypt, Jordan, Morocco and Oman). Purposive sampling was employed to identify habitual (regular) healthy WPS (smoked 3 or more WP per week for 3 or more years); CS (smoked 5 or more cigarettes daily for 3 or more years); and non-smokers. Respiratory symptoms were assessed using the European Community Respiratory Health Survey and the American Thoracic Society and the Division of Lung Diseases Questionnaire. Health-related quality of life was measured using the Short-Form 12. Demographic, environmental and lifestyle factors also were measured.

Result

The analytic sample included 135 WPS, 303 CS, and 300 non-smokers. Either tobacco group had significantly greater proportions of males than the non-smoker group. A significantly lower proportion of non-smokers (than either tobacco group) was overweight or obese. Average numbers of reported respiratory symptoms were 5.1, 5.8, and 2.9 in WPS, CS, and non-smokers, respectively. In multivariable regressions controlling for environmental exposures, body mass index, and physical activity, WPS and CS exhibited significantly higher rates of respiratory symptoms than non-smokers (1.6 times greater and 1.9 times greater rate of respiratory symptoms than non-smokers, respectively). Non-smokers reported significantly higher scores for general health relative to either WPS or CS.

Conclusion

Relative to their young non-smoking counterparts, young habitual WPS exhibit a significant burden of respiratory symptoms that is comparable to that observed with CS. Young WPS (and CS), despite their age, may be well on their way to developing respiratory disease.

Multiomic analysis of oral keratinocytes chronically exposed to shisha

BACKGROUND

Tobacco is smoked in different form including cigarettes and water pipes. One popular form of water pipe smoking especially in Middle Eastern countries is shisha smoking. Shisha has been associated with various diseases including oral cancer. However, genomic alterations and gene expression changes associated with chronic shisha exposure have not been previously investigated.

OBJECTIVES

Whole-exome sequencing and gene expression profiling of immortalized human oral keratinocytes (OKF6/TERT1) cells chronically treated with 0.5% shisha extract for a period of 8 months was undertaken to characterize molecular alterations associated with shisha exposure.

METHODS

Genomic DNA and RNA were extracted and preprocessed as per manufacturer's instruction and subjected to whole-exome and transcriptome sequencing using Illumina HiSeq2500 platform. Exome was analyzed using GATK pipeline whereas RNA-Seq data was analyzed using HiSat2 and HTSeq along with DESeq to elucidate differentially expressed genes.

RESULTS

Whole-exome sequence analysis led to identification of 521 somatic missense variants corresponding to 389 genes RNA-Seq data revealed 247 differentially expressed genes (≥2-fold, P-value<0.01) in shisha treated cells compared to parental cells. Pathway analysis of differentially expressed genes revealed that interferon-signaling pathway was significantly affected. We predict activation of MAPK1 pathway which is known to play a key role in oral cancer. We also observed allele specific expression of mutant LIMA1 based on RNA-Seq dataset.

CONCLUSION

Our findings provide insights into genomic alterations and gene expression pattern associated with oral keratinocytes chronically exposed to shisha.

Health Effects Reported by Adolescent Water Pipe and/or Cigarette Smokers Compared to Nonsmokers

PURPOSE

The purpose of this study was to determine the prevalence of respiratory and/or physical fitness health problems in adolescent (ages 18-21) water pipe (WP) smokers (with or without cigarette smoking), cigarette-only smokers, and nonsmokers.

METHODS

A comparative four-group study design was used to recruit a non-probability sample of 153 WP smokers only, 103 cigarette smokers only, and 102 cigarette+WP smokers along with 296 nonsmokers. Our hypothesis was that youth who smoked WPs and/or cigarettes would report more respiratory problems and/or poorer physical fitness than those who did not smoke.

RESULTS

The results showed that coughs were significantly associated with smoking in all three of the smoking groups (p < .05). Cigarette-only smokers reported the most adverse outcomes with more wheezing, difficulty breathing, and less ability to exercise without shortness of breath. A dose-response analysis showed similar patterns of adverse health effects for both WP and cigarette smokers. The combined use of both products was not appreciably worse than smoking one product alone. This could be due to cigarette+WP smokers' reporting using less of the respective products when only one product was smoked.

CONCLUSIONS

Even during the adolescent years, WP and/or cigarette smoking youth experienced reportable negative health effects.

Epidemiology and Adverse Consequences of Hookah/Waterpipe Use: A Systematic Review

Hookah smoking is becoming a popular trend globally. Waterpipe smoking is the second most prevalent form of alternate tobacco products. The rapid increase in hookah use is because of the misconception prevalent in society that hookah smoking is less harmful than cigarette smoking. Smoking ban policies had given impetus of switching from cigarette smoking to alternate tobacco products like waterpipe. Hookah users regard hookah to be more socially acceptable, less stigmatizing with flavors and to alleviate cigarette craving symptoms. Newer basic science research on animal models and human cells has shown consistently mutagenic, oxidative, and inflammatory changes that could cause possible health effects of premalignant oral lesion and chronic diseases like atherosclerosis and chronic obstructive pulmonary disease. Studies on the chemistry of waterpipe smoke had shown alarming results with the smoke containing seven carcinogens, 39 central nervous system depressants, and 31 respiratory irritants. Enormous data exist showing waterpipe smoking causing various health effects. Hookah smoking effects on cardiovascular disease is additive with hookah containing a significant amount of nicotine, tar, and heavy metals causing both acute and chronic effects on the cardiovascular system. These effects include increased heart rate, blood pressure, prevalence of coronary heart disease, heart failure, ST-segment elevation myocardial ischemia, recurrent ischemia, and worse outcomes including mortality related to these diseases. The objectives of the review are to assess the factor associated with the increasing use of hookah, its health effects, options for hookah smoking cessation, and public health policy initiatives to mitigate waterpipe use.

Airway reactivity to mannitol is similarly increased in chronic cigarette and water pipe smokers

Background

In contrast to cigarette smoking, the association between water pipe smoking and airway hyperresponsiveness remains widely unexplored.

Methods

A bronchoprovocation challenge with mannitol was performed in young adults recruited at the University of Basel, Switzerland. Subjects were categorized as acute water pipe smokers (single episode of water pipe smoking, no or <0.5 pack-years cigarette smoking); chronic water pipe smokers (weekly for ≥4 weeks, no or <0.5 pack-years cigarette smoking); cigarette smokers (no water pipe smokers); and never-smokers (no cigarette or water pipe smokers). Primary outcomes were airway reactivity as measured by the response-to-dose ratio (RDR) and airway responsiveness measured by the provocation dose to cause a 15% fall in forced expiratory volume in 1s (FEV₁; PD₁₅).

Results

Seventy-four subjects with a mean age of 22.5±2.5 years and FEV₁ % predicted 90.1%±8.6% were included. Subgroups were matched in terms of age, gender, and spirometry results. RDR in chronic water pipe smokers and cigarette smokers was similar (0.013%/mg [0.010–0.015] vs 0.023%/mg [0.011–0.051], respectively; p=0.12) but significantly higher than in never-smokers (0.007%/mg [0.005–0.010], p<0.01). Neither a history of asthma (p=0.88) nor a positive skin prick test (p=0.69) was associated with increased airway reactivity to the mannitol challenge test. PD₁₅ differed significantly between cigarette smokers and never-smokers (155 mg [115–395] vs 315 mg [155–475], respectively; p=0.04).

Conclusion

Weekly water pipe smoking may increase airway reactivity to a similar extent as cigarette smoking.

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.

A Man in His 20s With Diffuse Lung Opacities and Acute Respiratory Failure After Hookah Smoking

A man in his 20s with no medical history presented with 2 days of progressively worsening shortness of breath accompanied by subjective fevers, chills, body aches, decreased appetite, night sweats, and cough producing nonbloody sputum. He denied childhood lung diseases, allergies, or a family history of lung disease. He did not smoke cigarettes but had smoked hookah in Saudi Arabia before moving to the United States 1 month before presentation and had restarted 2 days before the start of symptoms. He denied travel outside of the northeastern United States. He did not take medications, use illicit drugs, or engage in high-risk behavior.

Water-pipe smoke condensate increases the internalization of Mycobacterium Bovis of type II alveolar epithelial cells (A549)

BACKGROUND

Tuberculosis (TB) is a major global health problem, and there is an association between tobacco smoke and TB. Water pipe smoking has become an increasing problem not only in Middle Eastern countries but also globally because users consider it as safer than cigarettes. The presence of high levels of toxic substances in water-pipe smoke may be a predisposing factor that enhances the incidence of pulmonary disorders. For example, uncontrolled macropinocytosis in alveolar epithelial cells following exposure to water-pipe smoke may predispose subjects to pulmonary infection. Here, we studied the effects of water-pipe condense (WPC) on the internalization of Mycobacterium Bovis BCG by macropinocytosis in the alveolar epithelial cell line A549.

METHODS

A549 cells were exposed to WPC (4 mg/ml) for 24, 48, 72 and 96 h. Cell viability was studied using the methyl thiazolyldipenyl-tetrazolium bromide (MTT) reduction assay and proliferation by bromodeoxyUridine (BrdU) incorporation. Cells were exposed to FITC-Dextran (1 mg/ml) (as a control) and FITC-BCG (MOI = 10) for 20 min at 37 °C before cells were collected and the uptake of BCG-FITC determined by flow cytometry. Similar experiments were performed at 4 °C as a control. The Rho-associated protein kinase (ROCK) inhibitor Y-27632 (1 μM) was used to assess the mechanism by which WPC enhanced BCG uptake.

RESULTS

WPC (4 mg/ml) increased the uptake of BCG-FITC after 72 (1.3 ± 0.1 fold, p < 0.05) and 96 (1.4 ± 0.05 fold, p < 0.05) hours. No effect on BCG-FITC uptake was observed at 24 or 48 h. WPC also significantly increased the uptake of FITC-Dextran (2.9 ± 0.3 fold, p < 0.05) after 24 h. WPC significantly decreased cell viability after 24 (84 ± 2%, p < 0.05), 48 (78±, 3%, p < 0.05), 72 (64 ± 2%, p < 0.05) and 96 h (45 ± 2%, p < 0.05). Y-27632 completely attenuated the increased uptake of BCG by WPC. Cell proliferation showed a decreasing trend in a time-dependent manner with WPC exposure.

CONCLUSION

WPC exposure increased epithelial cell endocytosis activity and death as well as enhancing their capacity for macropinocytosis. Our in vitro data indicates possible harmful effects of WPC on the ability of lung epithelial cells to phagocytose mycobacterium.

Increasing popularity of waterpipe tobacco smoking and electronic cigarette use: Implications for oral healthcare

Cigarette smoking increases the risk of developing several systemic conditions including cancer, cardiovascular and pulmonary diseases. Cigarette smoking is also detrimental to oral health as it increases the incidence and severity of oral cancer, periodontal diseases and peri-implantitis, as well as impacting negatively on the dental patients' response to therapy. Therefore, consideration of smoking behavior and recommendation of smoking cessation are important parts of dental treatment planning. However, cigarettes are no longer the most popular form of tobacco use among adolescents in the United States and globally. In recent years, tobacco smoking using a waterpipe ("hookah," "shisha") and use of electronic cigarettes (ECIGs) has increased significantly. Thus, dental clinicians likely will treat more patients who are waterpipe and/or ECIG users. Yet, the literature on the health effects of waterpipe and ECIGs use is sparse. Both waterpipe and ECIGs deliver the dependence-producing drug nicotine. Waterpipe tobacco smoking has been associated with periodontitis, dry socket, premalignant lesions, and oral and esophageal cancer. The health effects of long-term ECIG use are unknown. The purpose of this review is to inform healthcare professionals about waterpipes and ECIGs, highlight emerging evidence on the biological effects of these increasingly popular tobacco products, and introduce perspectives for dental patient management and future research.

Waterpipe smoking induces epigenetic changes in the small airway epithelium

Waterpipe (also called hookah, shisha, or narghile) smoking is a common form of tobacco use in the Middle East. Its use is becoming more prevalent in Western societies, especially among young adults as an alternative form of tobacco use to traditional cigarettes. While the risk to cigarette smoking is well documented, the risk to waterpipe smoking is not well defined with limited information on its health impact at the epidemiologic, clinical and biologic levels with respect to lung disease. Based on the knowledge that airway epithelial cell DNA methylation is modified in response to cigarette smoke and in cigarette smoking-related lung diseases, we assessed the impact of light-use waterpipe smoking on DNA methylation of the small airway epithelium (SAE) and whether changes in methylation were linked to the transcriptional output of the cells. Small airway epithelium was obtained from 7 nonsmokers and 7 light-use (2.6 ± 1.7 sessions/wk) waterpipe-only smokers. Genome-wide comparison of SAE DNA methylation of waterpipe smokers to nonsmokers identified 727 probesets differentially methylated (fold-change >1.5, p<0.05) representing 673 unique genes. Dominant pathways associated with these epigenetic changes include those linked to G-protein coupled receptor signaling, aryl hydrocarbon receptor signaling and xenobiotic metabolism signaling, all of which have been associated with cigarette smoking and lung disease. Of the genes differentially methylated, 11.3% exhibited a corresponding significant (p<0.05) change in gene expression with enrichment in pathways related to regulation of mRNA translation and protein synthesis (eIF2 signaling and regulation of eIF4 and p70S6K signaling). Overall, these data demonstrate that light-use waterpipe smoking is associated with epigenetic changes and related transcriptional modifications in the SAE, the cell population demonstrating the earliest pathologic abnormalities associated with chronic cigarette smoking.