Pleural Diseases in Connective Tissue Diseases

Connective tissue diseases (CTD) are heterogeneous, immune-mediated inflammatory disorders often presenting with multiorgan involvement. With the advent of high-resolution computed tomography, CTD-related pleuritis-pleural thickening and effusion-is now increasingly recognized early in the disease trajectory. The natural history of CTD-related pleural effusions varies from spontaneous resolution to progressive fibrothorax with ventilatory impairment. Treatment of the underlying CTD is necessary to manage the pleural disease. Depending on the degree of symptom burden and physiological insult, specific treatment of pleural disease can include monitoring, repeated aspirations, systemic anti-inflammatory medication, and surgical decortication.

National survey on management of spontaneous pneumothorax from emergency department to specialised treatment: room for improvement

Introduction

Spontaneous pneumothorax (SP) affects both young, otherwise healthy individuals and older persons with known underlying pulmonary disease. Initial management possibilities are evolving and range from observation to chest tube insertion. SP guidelines suggest an individualized approach based on multiple factors such as symptoms, size of pneumothorax, comorbidity and patient preference.

Aim

With this Danish national survey we aimed to map organization of care including involved specialties, treatment choice, training, and follow-up plans to identify aspects, and optimization of spontaneous pneumothorax management.

Method

A survey developed by the national interest group for pleural medicine was sent to all departments of emergency medicine, thoracic surgery, respiratory medicine, and to relevant departments of abdominal or orthopaedic surgery.

Results

The response rate was 75 % (47 of 65). Overall, 21% of responding departments had no guideline for SP management, which was provided by multiple specialties with marked heterogeneity in choice of treatment including tube size, management during admission, and referral procedure to follow-up. Few departments required procedure training, and nearly all of the responders called for improvements in management of pneumothorax.

Conclusion

This survey suggests that SP management and care is delivered heterogeneously across Danish hospitals with marked difference between respiratory physicians, emergency physicians, general surgeons and thoracic surgeons. It is therefore likely that management is sub-optimal. There is a need for a common Danish SP guideline to ensure optimal treatment across involved specialties.

COVID-19-Related Pleural Diseases

Coronavirus disease 2019 (COVID-19)-related pleural diseases are now well recognized. Since the beginning of the pandemic, increasing cases of pleural diseases including pneumothorax, pneumomediastinum, and pleural effusion with severe COVID-19 infection have attracted the attention of physicians and are not incidental or due to barotrauma. The complicated course of COVID-19 illness highlights the complex pathophysiological underpinnings of pleural complications. The management of patients with pneumothorax and pneumomediastinum is challenging as the majority require assisted ventilation; physicians therefore appear to have a low threshold to intervene. Conversely, pleural effusion cases, although sharing some similar patient characteristics with pneumothorax and pneumomediastinum, are in general managed more conservatively. The evidence suggests that patients with COVID-19-related pleural diseases, either due to air leak or effusion, have more severe disease with a worse prognosis. This implies that prompt recognition of these complications and targeted management are key to improve outcomes.

Achieving Molecular Profiling in Pleural Biopsies: A Multicenter, Retrospective Cohort Study

BACKGROUND

Pleural biopsy findings offer greater diagnostic sensitivity in malignant pleural effusions compared with pleural fluid. The adequacy of pleural biopsy techniques in achieving molecular marker status has not been studied, and such information (termed "actionable" histology) is critical in providing a rational, efficient, and evidence-based approach to diagnostic investigation.

RESEARCH QUESTION

What is the adequacy of various pleural biopsy techniques at providing adequate molecular diagnostic information to guide treatment in malignant pleural effusions?

STUDY DESIGN AND METHODS

This study analyzed anonymized data on 183 patients from four sites across three countries in whom pleural biopsy results had confirmed a malignant diagnosis and molecular profiling was relevant for the diagnosed cancer type. The primary outcome measure was adequacy of pleural biopsy for achieving molecular marker status. Secondary outcomes included clinical factors predictive of achieving a molecular diagnosis.

RESULTS

The median age of patients was 71 years (interquartile range, 63-78 years), with 92 of 183 (50%) male. Of the 183 procedures, 105 (57%) were local anesthetic thoracoscopies (LAT), 12 (7%) were CT scan guided, and 66 (36%) were ultrasound guided. Successful molecular marker analysis was associated with mode of biopsy, with LAT having the highst yield and ultrasound-guided biopsy the lowest (LAT vs CT scan guided vs ultrasound guided: LAT yield, 95%; CT scan guided, 86%; and ultrasound guided, 77% [P = .004]). Biopsy technique and size of biopsy sample were independently associated with successful molecular marker analysis. LAT had an adjusted OR for successful diagnosis of 30.16 (95% CI, 3.15-288.56; P = .003) and biopsy sample size an OR of 1.18 (95% CI, 1.02-1.37) per millimeter increase in tissue sample size (P < .03).

INTERPRETATION

Although previous studies have shown comparable overall diagnostic yields, in the modern era of targeted therapies, this study found that LAT offers far superior results to image-guided techniques at achieving molecular profiling and remains the optimal diagnostic tool.

Value of SPECT/CT in the diagnosis of avascular necrosis of the head of femur: A meta-analysis

INTRODUCTION

To evaluate the diagnostic value of single photon emission computed tomography/computed tomography (SPECT/CT) in patients with avascular necrosis (AVN) of the femoral head.

METHODS

A search of the databases PubMed, ScienceDirect, and Google Scholar was undertaken using targeted index word. Studies satisfying inclusions and exclusions criteria were identified and additional related literature sources were considered. Analysis included pooled sensitivity and specificity, odds ratio (OR), and receiver operating characteristic (ROC) analysis.

RESULTS

Seven studies were identified that specifically related to the diagnostic accuracy of SPECT/CT in the detection or characterisation of AVN of the femoral head. These were included in the meta-analysis. The pooled sensitivity and specificity were 94% (95% confidence interval of 87-97%) and 75% (95% confidence interval of 68-81%) respectively, the OR was 44.5 (with a 95% confidence interval of 18.2-108.6), and the area under the SROC was 93.73% (with a 95% confidence interval of 89.2%-98.3%).

CONCLUSION

This meta-analysis provides strong evidence of the high diagnostic efficacy of SPECT/CT in the evaluation of AVN of the femoral head.

IMPLICATIONS FOR PRACTICE

In the absence of or contraindication to MRI, SPECT/CT is able to provide a suitable alternative for diagnosis of AVN of the head of femur.

COVID-19 and pneumothorax: a multicentre retrospective case series

INTRODUCTION

Pneumothorax and pneumomediastinum have both been noted to complicate cases of coronavirus disease 2019 (COVID-19) requiring hospital admission. We report the largest case series yet described of patients with both these pathologies (including nonventilated patients).

METHODS

Cases were collected retrospectively from UK hospitals with inclusion criteria limited to a diagnosis of COVID-19 and the presence of either pneumothorax or pneumomediastinum. Patients included in the study presented between March and June 2020. Details obtained from the medical record included demographics, radiology, laboratory investigations, clinical management and survival.

RESULTS

71 patients from 16 centres were included in the study, of whom 60 had pneumothoraces (six with pneumomediastinum in addition) and 11 had pneumomediastinum alone. Two of these patients had two distinct episodes of pneumothorax, occurring bilaterally in sequential fashion, bringing the total number of pneumothoraces included to 62. Clinical scenarios included patients who had presented to hospital with pneumothorax, patients who had developed pneumothorax or pneumomediastinum during their inpatient admission with COVID-19 and patients who developed their complication while intubated and ventilated, either with or without concurrent extracorporeal membrane oxygenation. Survival at 28 days was not significantly different following pneumothorax (63.1±6.5%) or isolated pneumomediastinum (53.0±18.7%; p=0.854). The incidence of pneumothorax was higher in males. 28-day survival was not different between the sexes (males 62.5±7.7% versus females 68.4±10.7%; p=0.619). Patients aged ≥70 years had a significantly lower 28-day survival than younger individuals (≥70 years 41.7±13.5% survival versus <70 years 70.9±6.8% survival; p=0.018 log-rank).

CONCLUSION

These cases suggest that pneumothorax is a complication of COVID-19. Pneumothorax does not seem to be an independent marker of poor prognosis and we encourage continuation of active treatment where clinically possible.

An Overview of the Pathophysiology of Metabolic Changes and Their Sequence of Occurrence in Obese Diabetic Females: A Narrative Review

Obesity and diabetes both mediate their effects through insulin resistance and frequently co-exist. Insulin resistance is one of the key factors in the development of the metabolic syndrome. Adult females tend to develop obesity more frequently than males. One of the factors causing this difference is the pattern of changes that occur as females age from pre-menopausal to the post-menopausal stage, causing a change in the pattern of accumulation of fats. Several studies have explored and described the association between obesity and metabolic syndrome and their effect on type II diabetes. We conducted our literature search using PubMed and Google Scholar as our primary databases. We selected a total of 49 articles for review after applying the inclusion and exclusion criteria and removing the duplicate articles. We chose the full-text articles that were published in the English language only. The selected studies were randomized controlled trials and review papers. The reviewed articles showed that visceral fat, central obesity, and fasting blood sugar of post-menopausal is higher than in pre-menopausal women and needs adequate management. More studies are needed in the future to explore the patterns of the metabolic changes in obese females to provide early and better management of diabetes and prevent related complications.

LRFN2 gene variant rs2494938 provides susceptibility to esophageal cancer in the population of Jammu and Kashmir

Background

Leucine-rich repeat and fibronectin type 2 gene (LRFN2) variant rs2494938 has recently been found associated with esophageal cancer in a genome-wide association study in an Asian population. However, this association has not been replicated in any Indian population despite high incidence of the disease.

Materials and Methods

In the present case-control study, 166 cases and 459 controls were included. Taqman assay technique using real-time PCR was employed to investigate the association of the variant with esophageal cancer in the population of Jammu and Kashmir (J&K). The Hardy-Weinberg equilibrium for rs2494938 was assessed using the Chi-square test. The allele- and genotype-specific risk was estimated by odds ratio (OR) with 95% confidence interval (CI).

Results

Variant rs2494938 was observed to be significantly associated with esophageal cancer with an allelic OR of 1.59 (1.23-2.04 at 95% CI, P = 0.0003).

Conclusion

The study highlights LRFN2 as a candidate gene for esophageal cancer susceptibility in the population of J&K and calls for a detailed study with a large sample size and involving more ethnic groups of India.

Formulation and in-vitro characterization of Capsaicin loaded ethosomes

The ability of ethosomes to entrap capsaicin was evaluated using four methods of preparation that are; hot method, cold method, classic method and injection method. The ethosomes were prepared, optimized and characterized with the aim to identify a technique best suitable for their formulation. Vesicle shape, size and entrapment efficiency was determined by scanning electron microscopy, dynamic light scattering and ultracentrifugation techniques, respectively. Vesicle sizes varied from an average of 15nm - 400nm depending on the concentrations of phospholipid, ethanol and method of preparation. The formulations demonstrated entrapment efficiency of 29-81% with maximum entrapment obtained in formulations prepared with hot method having high concentration of ethanol. The homogeneity index was measured with Zetasizer that showed formulation prepared with hot method to be more uniform in size distribution having PDI 0.162 while injection method of preparation yielded a moderately broad polydispersity of vesicles (0.276). Physical stability assessment done by storing the selected formulation samples at 4°C and 25°C indicated the refrigerator temperature to be the best for retention of drug in ethosomal vesicles. All formulations kept in refrigerator adequately retained capsaicin during the two months of stability studies while those at ambient temperature noticeably showed leaked drug from vesicles. FTIR analysis showed capsaicin and phospholipid to be compatible with each other with no sign of interaction. DSC studies evidently showed lowering of transition temperature of phospholipid from 327.13°C to 111.63°C in ethosomal formulation due to the presence of ethanol. It was concluded that capsaicin ethosomes can be successfully prepared to employ four different methods and their characterization parameters indicate hot method to be effective for preparation of nano-sized uniform, homogeneous and stable capsaicin ethosomes.

Association of Activity Altering Genotypes - Tyr113His and His139Arg in Microsomal Epoxide Hydrolase Enzyme with Esophageal Squamous Cell Carcinoma

The study aimed to explore the relationship of microsomal epoxide hydrolase (mEH) exon 3 (Tyr113His) and exon 4 (His139Arg) polymorphisms and predicted mEH activity with esophageal squamous cell carcinoma (ESCC) risk. 482 histologically confirmed cases and equal number of matched controls were analyzed by polymerase chain reaction-restriction length polymorphism (PCR-RFLP). Conditional logistic regression models were used to examine the association of polymorphisms with ESCC. We noted exon 3 slow genotype (OR = 6.57; CI 3.43-12.57) as well as predicted low mEH activity (OR = 3.99; CI 2.32-6.85) was associated with the ESCC risk. Elevated ESCC risk estimates were seen in smokers independent of genotypes but the association was stronger among smokers with exon 3 variant (OR = 6.67; 3.29-13.53) and low activity (OR = 7.52; CI 3.46-16.37) genotypes. Positive family history of cancer synergistically increased ESCC risk in the individuals who harbored exon 3 (OR = 13.59; CI 5.63-32.81) or altered mEH activity genotypes (OR = 13.35; CI 5.10-34.94). Significant interaction was seen between mEH exon 3 and exon 4 genotypes (P = 0.006) and between predicted mEH activity and positive family history of cancer (P = 0.018). These findings suggest association of ESCC risk with mEH polymorphisms which get modified by tobacco smoking and positive family history of cancer.

Cortical venous infarcts and acute limb ischaemia in acute carbon monoxide poisoning: A rare case report

A case of carbon monoxide poisoning is presented with unusual complications; some of which have not been reported previously. A 48-years-old Asian male presented to the emergency department with dyspnoea, altered state of consciousness and pale discolouration of skin after being locked inside a factory room with burning coal. Patient was in acute respiratory distress. Arterial blood gas analysis showed respiratory acidosis with hypoxaemia. On 3rd day, patient developed dark coloured urine and right upper limb ischaemia. Acute renal failure was diagnosed. A doppler ultrasound showed stenosis of radial and ulnar arteries. 0n 8th day, patient regained consciousness and complained of loss of vision. An MRI of the brain revealed bilateral occipital venous infarcts. Cortical venous infarcts and arterial stenosis are rare complications of acute carbon monoxide poisoning.

Family history of cancer and the risk of squamous cell carcinoma of oesophagus: a case-control study in Kashmir, India

Background:

Only a few studies have examined the association between family history of cancer (FHC) and the risk of oesophageal squamous cell carcinoma (ESCC) in high incidence areas of ESCC. We conducted a case–control study to evaluate the relationship between FHC and ESCC risk in Kashmir, India, with analysis of detailed epidemiological data and information on multiple gene polymorphisms.

Methods:

We collected detailed information on FHC and a number of socio-demographic and lifestyle factors, and also obtained blood samples for genetic analysis from 703 histopathologically confirmed ESCC cases and 1664 individually matched controls. Conditional logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs).

Results:

Participants who had FHC showed a strong association with ESCC risk, and the risk was stronger when first-degree relatives (FDRs) had FHC (OR=6.8; 95% CI=4.6–9.9). Having a sibling with a cancer showed the strongest association (OR=10.8; 95% CI=6.0–19.3), but having a child with a cancer was not associated with ESCC risk. A history of any cancer in the spouse was also associated with ESCC risk (OR=4.1; 95% CI=1.6–10.2). Those with two or more relatives with FHC were at a higher risk of ESCC. After restricting FHC to familial ESCC only, the above associations were strengthened, except when spouses were affected with ESCC (OR=2.5; 95% CI=0.7–8.9). When we examined the associations between several single-nucleotide polymorphisms and ESCC in those with and without FHC, the associations of variant genotypes in cytochrome P450 (CYP) 2C19 and CYP2D6 and the wild genotype of CYP2E1 with ESCC were much stronger in those with FHC. The FHC had an additive interaction with several risk factors of ESCC in this population.

Conclusion:

Our results showed that FHC was strongly associated with ESCC risk in Kashmir. It seems both genetic factors and shared environment are involved in this association.

Impediments in foreign collaboration and conducting a high throughput molecular epidemiology research in India, an assessment from a feasibility study

BACKGROUND

Esophageal cancer is one of the world's top ten cancers. Its incidence, especially in the form of squamous cell carcinoma, is very high in some Asian regions including Kashmir. Jammu Kashmir and Ladakh are three provinces of Jammu and Kashmir, the northern most state of India. The three regions represent ethnically diverse socio-cultural populations with different incidences of esophageal squamous cell carcinoma (ESCC), a suitable setting for epidemiological studies. Hence, comparing the lifestyle, dietary habits and gene pools between the three regions will help in elucidation of ESCC etiology further. Therefore, to assess the possibility of conducting a larger case control study, we carried out a feasibility study to identify the collaborators as well as to explore patient referral systems and available research facilities in the state.

FINDINGS

We found conducting good cancer molecular epidemiology studies is difficult due to lack of proper research facilities and favourable administrative guidelines. The appropriate storage, transportation and analyses facilities of biological specimens for genome-wide association study and assessment of nutrition and exposure markers are unavailable or not sufficiently developed. Guidelines that can encourage scientific collaborations within the country seem unavailable. However, the administrative guidelines available under which the export of biological specimens out of India for analysis seems impossible. Consequently, Indian researchers are unable to collaborate with foreign scientists and render state of art research facilities inaccessible to them. Scientists in other parts of India may also confront with most of these impediments.

CONCLUSION

The study found that for conducting conclusive molecular epidemiological studies in India, referral system in hospitals is not systematic, scientific research facilities are inadequate as well as the guidelines for foreign collaboration  are not favourable.

Salt tea consumption and esophageal cancer: a possible role of alkaline beverages in esophageal carcinogenesis

Salt tea is the most commonly used beverage in Kashmir, India, where esophageal squamous cell carcinoma (ESCC) is the most common cancer. Salt tea is brewed in a unique way in Kashmir, usually with addition of sodium bicarbonate, which makes salt tea alkaline. As little information about the association between salt tea drinking and ESCC was available, we conducted a large-scale case-control study to investigate this association in Kashmir. We recruited 703 histologically confirmed cases of ESCC and 1664 controls individually matched to cases for age, sex, and district of residence. Conditional logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs). Participants who consumed >1,250 ml day(-1) showed an increased risk of ESCC (OR = 2.60, 95% CIs = 1.68-4.02). Samovar (a special vessel for the beverage preparation) users (OR = 1.77, 95% CIs 1.25-2.50) and those who ate cereal paste with salt tea (OR = 2.14, 95% CIs = 1.55-2.94) or added bicarbonate sodium to salt tea (OR = 2.12, 95% CIs = 1.33-3.39) were at higher risk of ESCC than others. When analysis was limited to alkaline tea drinkers only, those who both consumed cereal paste with salt tea and used samovar vessel were at the highest risk (OR = 4.58, 95% CIs = 2.04-10.28). This study shows significant associations of salt tea drinking and some related habits with ESCC risk.

CYP1A1 and CYP2E1 genotypes and risk of esophageal squamous cell carcinoma in a high-incidence region, Kashmir

The study analyzed the relationship between genetic polymorphisms of phase I xenobiotic metabolizing enzymes, cytochromes P450 (CYP) 1A1 and CYP2E1 and esophageal squamous cell carcinoma (ESCC) in Kashmir, India. The different genotypes of CYP1A1 and CYP2E1 were analyzed by polymerase chain reaction and restriction fragment length polymorphism in 526 ESCC cases and equal number of matched controls. Conditional logistic regression models were used to assess the association of various genotypes with ESCC, gene-gene, and gene-environment interactions. High risk of ESCC was found in participants who carried CYP1A1 Val/Val genotype (OR=2.87; 95 % CI=1.00-8.44) and the risk increased in such individuals when c1/c1 of CYP2E1 genotype was also present (OR=5.68; 95 % CI=1.09-29.52). Risk due to CYP1A1 Val/Val genotype was further enhanced (OR=8.55; 95 % CI=1.86-42.20) when the analysis was limited to ever smokers. Participants who carried CYP2E1 c1/c2 genotype showed an inverse relation (OR=0.27; 95 % CI=0.17-0.43) with ESCC. The inverse association of CYP2E1 c1/c2 genotype was retained when CYP1A1 Ile/Ile was also present (OR=0.18; 95 % CI=0.09-0.32), as well as when analysis was limited to ever smokers (OR=0.45; 95 % CI=0.23-0.90). Significant interaction was found between CYP1A1 (Val/Val) and CYP2E1 (c1/c1) genotypes (OR=1.30; 95 % CI=1.12-1.51; P=0.001) and between CYP1A1 (Val/Val) and smoking (OR=1.31; 95 % CI=1.01-1.69; P=0.043). The study suggests CYP1A1 Val/Val and CYP2E1 c1/c1 genotypes are significantly associated with ESCC risk.

Contact with animals and risk of oesophageal squamous cell carcinoma: outcome of a case-control study from Kashmir, a high-risk region

BACKGROUND

Several studies have reported association between animal contact and some cancer types, including lymphohaematopoietic, colon, pancreatic and neurological malignancies. We aimed to investigate the association between animal contact and risk of oesophageal squamous cell carcinoma (ESCC) in a case-control study in Kashmir, India, area with a relatively high incidence of ESCC.

METHODS

We recruited 703 histologically confirmed ESCC cases and 1664 controls individually matched to the cases for age, sex and district of residence. Information, including on animal contact, was obtained in face-to-face interviews using a structured questionnaire. Conditional logistic regression models were used to calculate ORs and 95% CIs.

RESULTS

As compared with no contact with animals, daily close contact was associated with an increased risk of ESCC (OR 5.99; 95% CI 3.86 to 9.31) in models adjusted for several potential confounding factors, including multiple indicators of socioeconomic status. This association persisted in subgroups following stratification by a composite wealth score and occupation. Irregular contact with animals was not associated with ESCC risk. The association between duration of animal contact and ESCC risk was mixed; however, contact for more than 50 years was associated with an increased risk (OR 3.10; 95% CI 1.53 to 6.26). Frequency (p for trend, 0.001) and duration (p for trend, <0.001) of animal contact showed dose-response association with ESCC risk.

CONCLUSIONS

Our results suggest an association between long-term and daily close contact with animals and ESCC. This association needs to be investigated in further studies.

Socioeconomic status and esophageal squamous cell carcinoma risk in Kashmir, India

Studies have persistently associated esophageal squamous cell carcinoma (ESCC) risk with low socioeconomic status (SES), but this association is unexplored in Kashmir, an area with a high incidence of ESCC in the northernmost part of India. We carried out a case-control study to assess the association of multiple indicators of SES and ESCC risk in the Kashmir valley. A total number of 703 histologically confirmed ESCC cases and 1664 controls matched to the cases for age, sex, and district of residence were recruited from October 2008 to January 2012. Conditional logistic regression models were used to calculate unadjusted and adjusted odds ratios and 95% confidence intervals. Composite wealth scores were constructed based on the ownership of several appliances using multiple correspondence analyses. Higher education, living in a kiln brick or concrete house, use of liquefied petroleum gas and electricity for cooking, and higher wealth scores all showed an inverse association with ESCC risk. Compared to farmers, individuals who had government jobs or worked in the business sector were at lower risk of ESCC, but this association disappeared in fully adjusted models. Occupational strenuous physical activity was strongly associated with ESCC risk. In summary, we found a strong relationship of low SES and ESCC in Kashmir. The findings need to be studied further to understand the mechanisms through which such SES parameters increase ESCC risk.

Hookah smoking, nass chewing, and oesophageal squamous cell carcinoma in Kashmir, India

BACKGROUND

Although cigarette smoking is an established risk factor for oesophageal squamous cell carcinoma (ESCC), there is little information about the association between other smoking and smokeless tobacco products, including hookah and nass, and ESCC risk. We conducted a case-control study in Kashmir Valley, India, where hookah smoking, nass chewing, and ESCC are common, to investigate the association of hookah smoking, nass use, and several other habits with ESCC.

METHODS

We recruited 702 histologically confirmed ESCC cases and 1663 hospital-based controls, individually matched to the cases for age, sex, and district of residence from September 2008 to January 2012. Conditional logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs).

RESULTS

Ever-hookah smoking (OR=1.85; 95% CI, 1.41-2.44) and nass chewing (OR=2.88; 95% CI, 2.06-4.04) were associated with ESCC risk. These associations were consistent across different measures of use, including intensity, duration, and cumulative amount of use, and after excluding ever users of the other product and cigarette smokers. Our results also suggest an increased risk of ESCC associated with ever-gutka chewing and -bidi smoking. However, the latter associations were based on small number of participants.

CONCLUSION

This study shows that hookah and nass use are associated with ESCC risk. As prevalence of hookah use seems to be increasing among young people worldwide, these results may have relevance not only for the regions in which hookah use has been a traditional habit, but also for other regions, including western countries.