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Background Studying carcinogens in tobacco and nontobacco sources may be key to understanding the pathogenesis and geographic distribution of esophageal cancer. Methods The Golestan Cohort Study has been conducted since 2004 in a region with high rates of esophageal squamous cell carcinoma. For this nested study, the cases comprised of all incident cases by January 1, 2018; controls were matched to the case by age, sex, residence, time in cohort, and tobacco use. We measured urinary concentrations of 33 exposure biomarkers of nicotine, polycyclic aromatic hydrocarbons, volatile organic compounds, and tobacco-specific nitrosamines. We used conditional logistic regression to calculate odds ratios (ORs) and 95% confidence intervals for associations between the 90th vs the 10th percentiles of the biomarker concentrations and incident esophageal squamous cell carcinoma. Results Among individuals who did not currently use tobacco (148 cases and 163 controls), 2 acrolein metabolites, 2 acrylonitrile metabolites, 1 propylene oxide metabolite, and one 1,3-butadiene metabolite were significantly associated with incident esophageal squamous cell carcinoma (adjusted odds ratios between 1.8 and 4.3). Among tobacco users (57 cases and 63 controls), metabolites of 2 other volatile organic compounds (styrene and xylene) were associated with esophageal squamous cell carcinoma (OR = 6.2 and 9.0, respectively). In tobacco users, 2 tobacco-specific nitrosamines (NNN and N' -Nitrosoanatabine) were also associated with esophageal squamous cell carcinoma. Suggestive associations were seen with some polycyclic aromatic hydrocarbons (especially 2-hydroxynaphthalene) in nonusers of tobacco products and other tobacco-specific nitrosamines in tobacco users. Conclusion These novel associations based on individual-level data and samples collected many years before cancer diagnosis, from a population without occupational exposure, have important public health implications. [ABSTRACT FROM AUTHOR]

Background: Poor oral health has been linked to various systemic diseases, including multiple cancer types, but studies of its association with lung cancer have been inconclusive. Methods: We examined the relationship between dental status and lung cancer incidence and mortality in the Golestan Cohort Study, a large, prospective cohort of 50,045 adults in northeastern Iran. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for associations between three dental health measures (i.e., number of missing teeth; the sum of decayed, missing, or filled teeth (DMFT); and toothbrushing frequency) and lung cancer incidence or mortality with adjustment for multiple potential confounders, including cigarette smoking and opium use. We created tertiles of the number of lost teeth/DMFT score in excess of the loess adjusted, age- and sex-specific predicted numbers, with subjects with the expected number of lost teeth/DMFT or fewer as the reference group. Results: During a median follow-up of 14 years, there were 119 incident lung cancer cases and 98 lung cancer deaths. Higher DMFT scores were associated with a progressively increased risk of lung cancer (linear trend, p = 0.011). Compared with individuals with the expected DMFT score or less, the HRs were 1.27 (95% CI: 0.73, 2.22), 2.15 (95% CI: 1.34, 3.43), and 1.52 (95% CI: 0.81, 2.84) for the first to the third tertiles of DMFT, respectively. The highest tertile of tooth loss also had an increased risk of lung cancer, with a HR of 1.68 (95% CI: 1.04, 2.70) compared with subjects with the expected number of lost teeth or fewer (linear trend, p = 0.043). The results were similar for lung cancer mortality and did not change substantially when the analysis was restricted to never users of cigarettes or opium. We found no associations between toothbrushing frequency and lung cancer incidence or mortality. Conclusion: Poor dental health indicated by tooth loss or DMFT, but not lack of toothbrushing, was associated with increased lung cancer incidence and mortality in this rural Middle Eastern population. [ABSTRACT FROM AUTHOR]

Background: Metabolic dysfunction-associated fatty liver disease (MAFLD) is a rising global public health concern. It has been demonstrated that its prevalence and characteristics vary by region and racial/ethnicity. We aimed to investigate the prevalence of MAFLD and its characteristics among Turkmen and non-Turkmen ethnic groups in a multiethnic population region of Iran., Methods: In this cross-sectional study, we analyzed baseline data for 1614 participants, aged above 50 years, from the PolyIran-Liver trial who were randomly selected from Gonabad city and determined the prevalence of MAFLD and its demographic and metabolic disorders for both the Turkmen and non-Turkmen ethnic groups. Multivariate binary logistic regressions were applied to identify MAFLD-associated factors for men and women separately for the Turkmen and non-Turkmen populations., Results: The mean (SD) age of the participants was 59.1(6.7) years. Of the participants, 51.5% (n=831) were men, and 52.9% (n=854) were Turkmen. The prevalence of MAFLD among the overall study population was 39.8% (n=614). It was more common among women (45.8% vs. 34.1% in men, P <0.001), non-Turkmens (43.9% vs. 36.1% in Turkmens, P <0.001), and at age 50-64 (41.5% vs.36.1% in age≥65 P =0.004). The fully adjusted multivariate analysis in sex strata exhibited an independent negative association between Turkmen ethnicity only among men but not among women. The increased waist circumference (WC) was the most common metabolic disorder, observed in more than 95.5% of patients with MAFLD ( P <0.001). Multivariate analysis in sex/ethnic strata with adjustment for potential confounders revealed an independent association of MAFLD with increased WC, insulin resistance, impaired fasting glucose/diabetes type 2, and high alanine aminotransferase (ALT) among women in both ethnic groups while with elevated triglyceride (TG) only among Turkmen and high body mass index (BMI) only among non-Turkmen women. Increased WC had the strongest independent association with MAFLD among women and the highest odds ratio (OR) with MAFLD in Turkmen women (OR: 6.10; 95% CI 1.56-23.86 vs. 4.80 in non-Turkmen women). Among men, MAFLD was independently associated with insulin resistance, high BMI, and high ALT in both ethnic groups and elevated TG only in non-Turkmen men (all P <0.001). Insulin resistance had the strongest independent OR with MAFLD among men with similar size in both ethnic groups (4.68 [95% CI 2.56-8.55]) in non-Turkmen men and 4.37 (95% CI 2.27-8.42 in Turkmen men)., Conclusion: This study revealed the high prevalence of MAFLD with a sex and ethnic disparity in the middle-aged population of Gonabad city. Further research is needed to understand the factors contributing to the higher prevalence of MAFLD in this region, particularly in women. Furthermore, considering the diverse ethnic population of Iran, it is suggested that future investigations on the sex and ethnic aspects of MAFLD in the Iranian population be conducted to provide targeted prevention strategies better suited for the Iranian population., Competing Interests: Competing Interests The authors declare no conflict of interest related to this work., (© 2024 Middle East Journal of Digestive Diseases.)

Background: Studying carcinogens in tobacco and nontobacco sources may be key to understanding the pathogenesis and geographic distribution of esophageal cancer., Methods: The Golestan Cohort Study has been conducted since 2004 in a region with high rates of esophageal squamous cell carcinoma. For this nested study, the cases comprised of all incident cases by January 1, 2018; controls were matched to the case by age, sex, residence, time in cohort, and tobacco use. We measured urinary concentrations of 33 exposure biomarkers of nicotine, polycyclic aromatic hydrocarbons, volatile organic compounds, and tobacco-specific nitrosamines. We used conditional logistic regression to calculate odds ratios (ORs) and 95% confidence intervals for associations between the 90th vs the 10th percentiles of the biomarker concentrations and incident esophageal squamous cell carcinoma., Results: Among individuals who did not currently use tobacco (148 cases and 163 controls), 2 acrolein metabolites, 2 acrylonitrile metabolites, 1 propylene oxide metabolite, and one 1,3-butadiene metabolite were significantly associated with incident esophageal squamous cell carcinoma (adjusted odds ratios between 1.8 and 4.3). Among tobacco users (57 cases and 63 controls), metabolites of 2 other volatile organic compounds (styrene and xylene) were associated with esophageal squamous cell carcinoma (OR = 6.2 and 9.0, respectively). In tobacco users, 2 tobacco-specific nitrosamines (NNN and N'-Nitrosoanatabine) were also associated with esophageal squamous cell carcinoma. Suggestive associations were seen with some polycyclic aromatic hydrocarbons (especially 2-hydroxynaphthalene) in nonusers of tobacco products and other tobacco-specific nitrosamines in tobacco users., Conclusion: These novel associations based on individual-level data and samples collected many years before cancer diagnosis, from a population without occupational exposure, have important public health implications., (Published by Oxford University Press 2023.)