Association between waterpipe smoking and lung cancer: a multicentre case-control study in Iran

OBJECTIVES

This study investigated the association between lung cancer and waterpipe smoking, which is an emerging global public health concern.

STUDY DESIGN

Multicentre case-control study.

METHODS

This study included 627 cases and 3477 controls from the Iranian Study of Opium and Cancer (IROPICAN) study, which was conducted between 2017 and 2020. One frequency-matched control for each lung cancer patient was selected by age, gender and residential place; however, this study used controls of four cancer types in the analyses. The multivariable logistic regression model estimated the odds ratio (OR) and 95% confidence intervals (CIs). Additional analyses were performed among 181 lung cancer cases and 2141 controls who were not cigarette smokers or opium or nass/pipe users.

RESULTS

The odds of lung cancer were higher among waterpipe smokers than never-smokers (OR = 1.3, 95% CI: 1.0-1.7). Results showed a higher OR of lung cancer for those who smoked the waterpipe daily (OR = 2.1, 95% CI: 1.4-3.0), smoked more than two heads per day (OR = 2.7, 95% CI: 1.8-4.0), had smoked for >20 years (OR = 1.9, 95% CI: 1.3-2.7), smoked more than 20 head-years (OR = 2.8, 95% CI: 1.9-4.1) and initiated smoking before the age of 30 years (OR = 1.7, 95% CI: 1.1-2.5). The association was only statistically significant for squamous cell carcinomas (OR = 1.8, 95% CI 1.2-2.7). Furthermore, this study observed a higher OR of lung cancer among exclusive waterpipe smokers (OR = 2.3, 95% CI: 1.6, 3.5).

CONCLUSIONS

Waterpipe smoking was associated with an increased risk of lung cancer. The association was stronger with higher frequency, duration and intensity of exposure to waterpipe smoking. The association increases in exclusive waterpipe smokers, which is likely due to controlling for residual confounding by cigarette smoking and opium consumption, and higher exposure levels in this subpopulation.

National Study of Opium and Cancer in Iran (IROPICAN): Study Protocol and Results of the Pilot Phase

Background: Several epidemiologic studies have reported that opium consumption is associated with higher risk of cancer and may indeed cause cancer. However, most of these studies were not primarily designed to study the effect of opium on cancer. Therefore, control selection and data collections methods were not optimized for this purpose. Aim: We designed a large multicenter case-control study to specifically investigate the association between opium use and risk of 4 cancer types (i.e., lung, bladder, head and neck and colorectal cancers). We will recruit 800 cases and 800 controls for each cancer in this project. Methods: So far we have collected 70% of the cases and controls. We report here the study protocol and results of the pilot phase. Results: During the pilot phase, we determined that hospital visitors are the most appropriate type of controls; 185 cases and 176 controls were enrolled. Controls are matched to cases for sex, age and place of residence. Collection of data using a comprehensive questionnaire, focused on measuring use of opium and its derivatives, was feasible. Underreporting of opium was estimated to be 30% among controls. Collection of other data, including data tobacco and alcohol use, and nutritional data using a food frequency questionnaire, was feasible. Biologic samples including blood and saliva sample were collected from cancer cases and controls. Results of the pilot phase and validation study were used to optimize the full study protocol and questionnaires. Conclusion: The pilot phase of the study showed that the study is feasible, the best method of control selection is from hospital visitors, and both questionnaire and biologic samples can be collected. In addition of the results from pilot phase, preliminary results from the main phase of this study will be presented.

Prevention of Disease Complications through Diagnostic Models: How to Tackle the Problem of Missing Data?

BACKGROUND

Diagnostic models are frequently used to assess the role of risk factors on disease complications, and therefore to avoid them. Missing data is an issue that challenges the model making. The aim of this study was to develop a diagnostic model to predict death in HIV/AIDS patients when missing data exist.

METHODS

HIV patients (n=1460) referred to Voluntary Consoling and Testing Center (VCT) of Shiraz southern Iran during 2004-2009 were recruited. Univariate association between variables and death was assessed. Only variables which had univariate P< 0.25 were selected to be offered to the Multifactorial models. First, patients with missing data on candidate variables were deleted (C-C model). Then, applying Multivariable Imputation via Chained Equations (MICE), missing data were imputed. Logistic regression was fitted to C-C and imputed data sets (MICE model). Models were compared in terms of number of variables retained in the final model, width of confidence intervals, and discrimination ability.

RESULT

About 22% of data were lost in C-C model. Number of variables retained in the C-C and MICE models was 2 and 6 respectively. Confidence Intervals (C.I.) corresponding to C-C model was wider than that of MICE. The MICE model showed greater discrimination ability than C-C model (70% versus 64%).

CONCLUSION

The C-C analysis resulted to loss of power and wide CI's. Once missing data were imputed, more variables reached significance level and C.I.'s were narrower. Therefore, we do recommend the application of the imputation method for handling missing data.

Waterpipe tobacco use among Iranian university students: correlates and perceived reasons for use

SETTING

Waterpipe smoking is becoming a global health crisis among youth.

OBJECTIVE

To identify the prevalence of waterpipe use among Iranian university students and to explore perceived reasons for use.

METHODS

A random sample of 1024 university students at two major universities in South Iran was enrolled in the study. A three-part questionnaire (baseline data, tobacco smoking status and perceived reasons for waterpipe use) was used. Students filled out the self-administered questionnaire in their classrooms.

RESULTS

The prevalence of waterpipe smoking in the respondents' lifetime and in the last 30 days was 42.5% and 18.7%, respectively. The mean age at initiation of waterpipe smoking was 16.3 ± 3.2 years. Ever smoking was positively associated with age and male sex, whereas no association was found regarding marital status. The highest odds of lifetime waterpipe smoking were observed in students with close friends who smoked the waterpipe (5.94, 95%CI 4.26-8.30). The most important perceived reason for waterpipe smoking as stated by students was enjoyment (55.8%).

CONCLUSION

Given the alarming prevalence of waterpipe smoking, preventive measures should be adopted among university students taking into account the influence of peers, siblings and parents in the lessening social tolerance of waterpipe smoking.

Laparatomy due to gastrointestinal complications after open heart surgery

AIM

Abdominal complications following open heart surgery remain rare but fatal events with mortality rates of 14.5% up to 100%. Manifestations and managements of these complications are varying. Approximately, 25% of patients with gastrointestinal complications require surgical management with obviously higher mortality risks. The aim of this study was to determine the perioperative prognostic factors of gastrointestinal complications with surgical consequences after cardiac surgery.

METHODS

The study enrolled 15.737 patients who underwent open heart surgery between January 2002 and September 2007. Sixteen (0.1%) persons required laparatomy due to postoperative gastrointestinal complications. Additionally, the preoperative, operative, and postoperative risk factors for this condition were studied.

RESULTS

Among the patients enrolled, 15.737 patients underwent open heart surgery while 16 (0.1%) required laparatomy procedures due to gastrointestinal complications. They were comprised of 11 (68.8%) men and 5 (31.3%) women at a mean age of 62.88±12.56 years. There was a history of hypertension in 9 (56.3%) patients, hypercholesterolemia in 11 (68.8%), renal failure in 4 (25%), previous CABG in 2 (12.5%) and PTCA in 2 (12.5%). Morbidity and mortality were significantly higher in this group of patients with a mortality rate of 68.8% (68.8% versus 1.6%).

CONCLUSION

Our multivariate logistic regression model identified the following parameters to be the prognostic factors for gastrointestinal complications with surgical consequences: a history of previous CABG, previous PTCA, preoperative renal failure, preoperative anticoagulant agent use, valve surgery, combined valve and CABG surgery, and intra-aortic balloon pump requirement with OR of 51.95, 4.623, 26.436, 0.140, 5.43, 11.469 and 3.76, respectively.

Effects of body mass index on early outcome of coronary artery bypass surgery

AIM

Obesity is commonly thought to be a risk factor for morbidity and mortality after cardiac surgery. The aim of the present study is to evaluate the effects of variations in body mass index on in-hospital outcome of coronary artery bypass grafting (CABG).

METHODS

The authors conducted a retrospective review of 10191 consecutive patients who had undergone isolated CABG at the center from February 2002 to November 2006. Patients were divided into four groups according to Body Mass Index (BMI). Underweight patients (BMI<18.5 kg/m(2)) were assigned to group 1 and obese patients (BMI 30 kg/m(2)) were put into group 4. Patients with normal BMI and those who were overweight were placed in group 2 and 3 respectively.

RESULTS

Analysis of the BMI groups showed: of 10191 patients 0.7% was underweight; 31.2% of cases had normal BMI, 47.1%; overweight and 21.0% were obese. Compared with other groups, the members of the obese group were younger, included more women and were more likely to have all the risk factors for coronary artery disease except for cigarette smoking (P<0.0001). The underweight patients had an excess of left main coronary artery disease, previous history of myocardial infarction. In-hospital mortality did not show any difference between groups (P=0.46). There was a significant increase in postoperative gastrointestinal complications among the underweight group in comparison with other groups (P=0.027).

CONCLUSIONS

According to this study, obese patients undergoing CABG are not at a greater risk of perioperative death and other adverse outcomes compared to normal weight. After CABG, underweight patients are at higher risk of developing gastrointestinal complications compared to normal patients.

Endovascular repair of post-surgical pseudoaneurysm of suprarenal abdominal aorta in a patient with Behcet's disease

Vascular Behcet's disease has a poor prognosis. This poor prognosis is due to postoperative complications including pseudoaneurysm with 50% occurrence after previous surgical repair of aneurysm especially at the site of surgery. It is suggested that the fragility of the vascular wall may play a major role in this recurrence. Recent studies have demonstrated the effectiveness of endovascular stent-grafting for recurrent aortic aneurysm in patients with Behcet's disease. We present a recurrent aneurysm of the abdominal aorta at a previously scarred operative site in a known case of Behcet's disease. We attempted an endovascular treatment.

Concomitant carotid endarterectomy and coronary artery bypass grafting versus staged carotid stenting followed by coronary artery bypass grafting

AIM

Significant carotid stenosis (>or=70%) in patients undergoing coronary artery bypass grafting (CABG) can increase the risk of perioperative cerebral vascular accident (CVA). In this study, we compared the results of two common operative strategies: concomitant carotid endarterectomy and CABG versus carotid stenting and CABG.

METHODS

This cohort study was conducted from January 2001 to September 2006. Significant carotid artery stenosis was detected in patients who were candidates for CABG at the Tehran Heart Center. The stenosis was detected by carotid Doppler screening and was confirmed by magnetic resonance angiography. Reluctant patients or those with previous major CVA, significant bilateral carotid stenosis and intracranial lesions were excluded. Patients were divided into 2 groups. Group A underwent concomitant carotid endarterectomy and CABG (n=19), while carotid stenting and CABG were done in group B (n=28).

RESULTS

The mean age in group A was 67.37+/-7.09 years and 65.57+/-8.13 years in group B. The mean hospital stay (days) was 18.68+/-7.95 in group A and 26.35+/-77.04 in group B (P=0.01). The median charge was dollars 252.79 in group A and dollars 2206.66 in group B (P <0.0001). There was a significant difference in frequency of hypotension and bradycardia between the 2 groups (P <0.05). There were 2 cases of in-hospital mortality in each group (10.5% and 7.1%, respectively). Two postoperative strokes occurred in group A and 3 in group B (10.5% and 10.7%, respectively).

CONCLUSION

Concomitant carotid endarterectomy and CABG is as safe as carotid stenting and CABG, with fewer neurologic events and less hypotension, bradycardia, cost and shorter hospital stay.

Early mortality predictors in coronary artery bypass grafting patients required intra-aortic balloon pump in perioperative and postoperative periods

AIM

The intra-aortic balloon pump (IABP) is commonly used for decreasing myocardial oxygen demand by systolic unloading in perioperative heart failure. The aim of this study was to determine perioperative prognostic factors for in-hospital mortality in coronary artery bypass grafting patients who received the intraaortic balloon pump.

METHODS

A total of 271 patients who underwent coronary artery bypass grafting and received intra-aortic balloon pump perioperatively between January 2002 and September 2006 were studied. The preoperative, operative and postoperative risk factors for early death were evaluated.

RESULTS

Early mortality rate in the study population was 17.3%. From variables entered into multivariate logistic regression the following parameters were identified as prognostic factors for early death: left main disease, diabetes, postoperative renal failure and cardiac arrest (P<0.05). The minor and major intra-aortic balloon pump related complications were not significant in univariate and multivariate analysis and its rate was 3.6%.

CONCLUSION

According to our study the mortality of IABP group is low compared to other studies, as well as IABP-associated complications. Also it revealed that there is no correlation between IABP-associated complications and early mortality.

Blood groups of the people of Ahwaz, Iran

ABO, Rh and MN blood groups were studied among the people of Ahwaz, Khuzistan, Iran. The people of Ahwaz are characterized by high frequencies of the blood groups 0 (41.16%), Rh-positive (90.0%) and MN (48.13%). These frequencies are significantly different from those obtained in other Iranian populations, which is caused by the co-operation of various factors.

Annuality of birth, delivery types and sex ratio in Tehran, Iran

616,638 births during 1967-1983 from a maternity hospital in Tehran (Iran) have been considered for the present study. The mean rate of normal delivery was 92.59%, that of Caesarean was 3.09%, that of wantose was 1.52% and finally that of forceps was 1.31%. Caesarean and wantose (vacuum extractor) delivery types showed an increasing trend, whereas the normal and forceps delivery types showed a decreased trend during the period under study. The secondary sex ratio was the highest in 1977 and the lowest in 1983 with a mean of 105.18. The twinning rate showed a decreasing trend during the above period.

Sex ratio in the Iranian urban and rural areas

Factors affecting the sex ratio are examined using data for 1,169,489 births occurring in rural and urban districts of Tehran, Iran, between 1971 and 1979. Attention is given to geographic, socioeconomic, psychological, and nutritional factors. It is found that "male births occurred more in Winter and Spring in the urban and rural areas, respectively. Female births occurred more in Fall in both urban and rural areas. Mean sex ratio was 108.20 in rural and 105.44 in urban areas." Reasons for the differentials between urban and rural areas are suggested.

Seasonality of birth and sex ratio in Tehran, Iran

234 218 births (1975-1983) from a hospital in Tehran have been analysed for seasonality of birth and sex ratio. The results show more births in winter and less births in fall. The sex ratio is higher in summer and lower in fall. The occurrence of multibirths shows higher twinning and triplet rates in spring and fall, respectively, whereas lower twinning and triplet rates occur in winter and summer, respectively. It could be demonstrated that geographical factors influence the rates of births and multibirths as well as the sex ratio.