Predictors of Transition in Different Stages of Smoking: A Longitudinal Study

Abstract We investigated longitudinally the prevalence of smoking according to three stages of smoking (never smoking, experimenting the smoking, and regular smoking), the rates of transition from one stage to another one, and determinant predictors of transition through these stages of smoking. Of all 10th grade students in Tabriz, 1785 students were randomly selected and assessed twice, with a 12-month interval, with respect to the changes of stage. The predictor variables were measured when the students were in the 10th grade. Logistic regression and principal component analysis were used to analysis data at grade 11. Of 1785 students, 14.3% (CI 95%: 12.3-16.4) and 2.8% (CI 95%: 2.0-4.0) of the never smokers became experimenters and regular smokers, respectively and 16.5% (CI 95%: 12.4-21.7) of the experimenters became regular smokers. Among never smokers, participating in smoker groups (OR = 1.24), having smoker friends (OR = 1.85) and a positive attitude towards smoking (OR = 1.22) predicted experimentation; and participating in smokers groups (OR = 1.35) and a lower socioeconomic class (OR = 0.36) predicted regular smoking. Among experimenters, students having general high risk behaviors (OR = 2.56) and participating in smoker groups (OR = 2.58) were distinguished as those who progressed to regular smoking in follow-up. Programs aimed at smoking prevention and intervention should incorporate plans which focus on predictors of transition through smoking stages, and targeting participation in smoker groups

Predictors of Transition in Different Stages of Smoking: A Longitudinal Study

AbstractBackground: We investigated longitudinally the prevalence of smoking according to three stages of smoking (never smoking, experimenting the smoking, and regular smoking), the rates of transition from one stage to another one, and determinant predictors of transition through these stages of smoking.Methods: Of all 10th grade students in Tabriz, 1785 students were randomly selected and assessed twice, with a 12-month interval, with respect to the changes of stage. The predictor variables were measured when the students were in the 10th grade. Logistic regression and principal component analysis were used to analysis data at grade 11.Findings: Of 1785 students, 14.3% (CI 95%: 12.3-16.4) and 2.8% (CI 95%: 2.0-4.0) of the never smokers became experimenters and regular smokers, respectively and 16.5% (CI 95%: 12.4-21.7) of the experimenters became regular smokers. Among never smokers, participating in smoker groups (OR = 1.24), having smoker friends (OR = 1.85) and a positive attitude towards smoking (OR = 1.22) predicted experimentation; and participating in smokers groups (OR = 1.35) and a lower socioeconomic class (OR = 0.36) predicted regular smoking. Among experimenters, students having general high risk behaviors (OR = 2.56) and participating in smoker groups (OR = 2.58) were distinguished as those who progressed to regular smoking in follow-up.Conclusion:Programs aimed at smoking prevention and intervention should incorporate plans which focus on predictors of transition through smoking stages, and targeting participation in smoker groups.Keyword: Smoking, Students, Risk-Taking, Longitudinal Studies, Peer Group, Epidemiology, Prevalence, Risk factor

Human Papillomavirus and Risk of Head and Neck SquamousCell Carcinoma in Iran

Human papillomavirus (HPV) causes a subset of head and neck squamous cell carcinoma (HNSCC). Knowledge of determinants of α-, β-, and γ-HPVs types in the oral cavity is required for a better understanding of HNSCC development. Oral rinse samples of 498 HNSCC cases and 242 controls from the IROPICAN study—a large multicenter case-control study in Iran—were screened for 21 α-HPV, 46 β-HPVs, and 52 γ-HPVs using bead-based HPV genotyping assays. α-HPVs were detected only in 1.2% of the patients and 2.9% of the controls from which HPV16 was the most prevalent type among participants. β-HPVs were detected in 43.8% of the patients and 38.6% of the controls where the lip and oral cavity (45.5%) had the highest positivity. Values for γ-HPV prevalence in patients and controls were 26.1% and 24.7%, respectively. The highest percentage of γ-HPV positivity was found in the larynx (30.4%). Concerning the β genus, HPV23 and HPV38 were the most prevalent types among the patients and controls, respectively. For the γ genus, SD2 in cases and HPV134 in controls were the most prevalent types. Overall, detection of α-HPVs (aOR, 0.40; 95% CI = 0.1 to 1.2; P = 0.11), β-HPVs (aOR, 1.9; 95% CI = 0.9 to 1.6; P = 0.29), and γ-HPVs infections (aOR, 1.04; 95% CI = 0.7 to 1.5; P = 0.83) was not associated with the HNSCC development. Our data did not suggest an HPV-related etiology for HNSCC pathogenesis. Nonetheless, this study provides novel insights into the diversity of β-, and γ-HPVs in different HNSCC anatomical subsites

Opium use and risk of bladder cancer: a multi-centre case-referent study in Iran

Background Bladder cancer (BC) is the 10th most common type of cancer worldwide and the fourth most common type of cancer in Iran. Opium use is considered as one of the risk factors for BC. We aim to assess the association between various parameters of opium use, which in Iran is mainly ingested or smoked in various forms, and the risk of BC. Method In this multi-centre case-referent study in Iran, 717 BC cases and 3477 referents were recruited to the study from May 2017 until July 2020. Detailed histories of opium use (duration, amount, frequency) and potential confounders were collected by trained interviewers. Multivariable unconditional logistic regression models were used to measure adjusted odds ratio (OR) and 95% confidence intervals (CI). The ORs were adjusted for age, gender, place of residence and pack-years of cigarette smoking. Results Regular opium consumption was associated with an increased risk of BC (OR 3.5, 95% CI: 2.8, 4.3) compared with subjects who never used opium. Compared with continuous users, the risk decreased to one-third for those who stopped opium more than 10 years ago. The adjusted OR for those who used both crude opium (teriak) and opium juice was 7.4 (95% CI: 4.1, 13.3). There was a joint effect of opium and tobacco (OR for users of both opium and tobacco 7.7, 95% CI: 6.0, 9.7). Conclusions Regular opium use is associated with an approximately 4-fold risk for BC. The OR decreases along with the increasing time since stopping opium use

Dietary Ruminant and Industrial Trans-Fatty Acids Intake and Colorectal Cancer Risk

As colorectal cancer (CRC) is largely due to modifiable lifestyle habits, the awareness on its risk factors is highly important. Dietary fatty acids have been linked to CRC risk. We explored the association between dietary trans fatty acids (TFAs) intake and CRC risk. We analyzed 865 CRC cases (434 in colon and 404 in rectum) and 3206 controls of the IROPICAN study, with data collected by trained interviewers using validated questionnaires. TFAs intake (industrial and ruminant types) was categorized into quartiles. Multivariate logistic regression models were built to calculate the odds ratios (OR) for the association between CRC and TFAs. We observed a positive association between industrial TFAs and colon cancer (OR for highest vs lowest quartile [ORQ4vsQ1] = 1.28, 95% confidence interval 1.07–1.54). A higher association was observed between industrial TFAs and CRC, occurring after 50 years of age. In addition, elaidic acid was associated with an increased risk of colon (ORQ4vsQ1 = 1.58, 1.24–2.02) and specifically of proximal colon cancer (OR Q4vsQ1 = 2.12, 1.40–3.20), as well as of rectum cancer (ORQ4vsQ1 = 1.40, 1.07–1.83). An inverse association was observed between ruminant TFAs intake and colon cancer risk (ORQ4vsQ1 = 0.80, 0.67–0.97). Industrial TFAs, such as semisolid/solid hydrogenated oils, may increase the risk of CRC, especially colon and proximal colon cancer. In contrast, ruminant TFAs do not appear to be associated with CRC. Awareness programs and regulatory actions regarding hydrogenated oils are warranted, given their high consumption through ultra-processed foods in more developed and less developed countries.publishedVersionPeer reviewe

Association between dietary fat intake and colorectal cancer : A multicenter case-control study in Iran

The evolving trends in colorectal cancer (CRC) as one of the most common malignancies worldwide, have likely been influenced by the implementation of screening programs and changes in lifestyle habits. Changing lifestyle, including the shift in diet composition with higher fat, sugar, and animal-source foods intake, led to an increasing burden of CRC in countries undergoing rapid socioeconomic improvement. Results for the link between specific fatty acids (FAs) and CRC are generally inconclusive and more limited in developing countries than elsewhere. This study aims to investigate the association between FA intakes and CRC and its anatomical subsites in a large Iranian case-control study. A food frequency questionnaire was used to collect information on dietary intake in 865 cases and 3206 controls. We conducted multivariate logistic regression models to calculate the odds ratio (OR) and 95% confidence interval (CI). We found positive association between CRC and high intake of dietary total fat (OR highest quartile Q4 = 1.77, 95% CI = 1.32–2.38), cholesterol (ORQ4 = 1.58, 95% CI = 1.22–2.05), and palmitoleic acid (ORQ4 = 2.16, 95% CI = 1.19, 3.91), and an inverse association with high intake of dietary heptanoic acid (ORQ4 = 0.33, 95% CI = 0.14, 0.79) and low intake of palmitic acid (OR lowest quartile Q2 = 0.53, 95% CI = 0.31–0.88). None of the fat variables were associated with rectal cancer. Our study suggests that the recommendation of limited consumption of fats may decrease the risk of CRC among the Iranian population.publishedVersionPeer reviewe

Lung cancer risk in relation to jobs held in a nationwide case-control study in Iran

Background: Globally, lung cancer is the most frequent occupational cancer, but the risk associated with the occupations or occupational environment in Iran is not clear. We aimed to assess occupations with the risk of lung cancer. Methods: We used the IROPICAN nationwide case-control study data including 658 incident lung cancer cases and 3477 controls. We assessed the risk of lung cancer in relation to ever working in major groups of International Standard Classification of Occupations, high-risk occupations for lung cancer and duration of employment and lung cancer subtype among construction workers and farmers while controlling for cigarette smoking and opium consumption. We used unconditional regression logistic models to estimate ORs for the association between increased lung cancer risk and occupations. Results: We observed elevated ORs for lung cancer in male construction workers (OR=1.4; 95% CI: 1.0 to 1.8), petroleum industry workers (OR=3.2; 95% CI: 1.1 to 9.8), female farmers (OR=2.6; 95% CI: 1.3 to 5.3) and female bakers (OR=5.5; 95% CI: 1.0 to 29.8). A positive trend by the duration of employment was observed for male construction workers (p< 0.001). Increased risk of squamous cell carcinoma was observed in male construction workers (OR=1.9; 95% CI: 1.2 to 3.0) and female farmers (OR=4.3; 95% CI: 1.1 to 17.2), who also experienced an increased risk of adenocarcinoma (OR=3.8; 95% CI: 1.4 to 9.9). Discussion: Although we observed associations between some occupations and lung cancer consistent with the literature, further studies with larger samples focusing on exposures are needed to better understand the occupational lung cancer burden in Iran.publishedVersionPeer reviewe

Dietary total antioxidant capacity and head and neck cancer: a large case-control study in Iran

BackgroundData on the association between head and neck cancer (HNC) and dietary factors are inconclusive. No study has so far investigated the association between dietary total antioxidant capacity (dTAC) and HNC concerning interactions with other risk factors.MethodPathologically confirmed new diagnosed HNC patients were included in this study. The control group was healthy hospital visitors who were frequently matched with patients on age (5 years interval), gender, and province of residence. Trained interviewers administered a validated Food Frequency Questionnaire (FFQ) to assess the participants’ food intake 1 year before the cancer diagnosis. Data on TAC scores of foods was collected by Ferric Reducing Antioxidant Power (FRAP) and Total Radical-trapping Antioxidant Parameters (TRAP) from published data. We applied logistic regression adjusted for age, sex, energy intake, socioeconomic status, province, opium use, alcohol use, physical activity, and dental health. We also studied the interaction of dTAC with tobacco smoking status, and opium use on the risk of HNC.ResultsWe recruited 876 HNC patients and 3,409 healthy controls. We observed a significant decrease in the odds of HNC with increasing dTAC scores. The OR of HNC for the third vs. the first tertile was 0.49 (95%CI 0.39–0.61) for FRAP and 0.49 (95%CI 0.39–0.62) for TRAP. Both dTAC scores were inversely associated with lip and oral (T3 ver. T1 OR = 0.51; 95%CI 0.36–0.71 for FRAP and OR = 0.59; 95% CI 0.44–0.82 for TRAP) and larynx (T3 ver. T1 OR = 0.43; 95%CI 0.31–0.61 for FRAP and OR = 0.38; 95% CI 0.26–0.55 for TRAP) cancers. There was no interaction between tobacco smoking, opium use; and TRAP or FRAP on the risk of HNC.ConclusionAn antioxidant-rich diet in terms of FRAP or TRAP could decrease the risk of HNC and its subtypes