Maternal education and its influence on child growth and nutritional status during the first two years of life: a systematic review and meta-analysis.

Background: The first 1000 days of life are critical for a child's health and development. Impaired growth during this period is linked to increased child morbidity, mortality, and long-term consequences. Undernutrition is the main cause, and addressing it within the first 1000 days of life is vital. Maternal education is consistently identified as a significant predictor of child undernutrition, but its specific impact remains to be determined. This study presents a systematic review and meta-analysis investigating the influence of high versus low maternal education levels on child growth from birth to age two, using population-based cohort studies. Methods: Databases including PubMed, Scopus, EMBASE, Web of Science, ERIC, and Google Scholar were searched from January 1990 to January 2024 using appropriate search terms. We included population-based cohort studies of healthy children aged two years and under and their mothers, categorizing maternal education levels. Child growth and nutritional outcomes were assessed using various indicators. Two reviewers independently conducted data extraction and assessed study quality. The Newcastle Ottawa scale was utilized for quality assessment. Random-effects models were used for meta-analysis, and heterogeneity was assessed using the Cochrane Q and I2 statistic. Subgroup and sensitivity analyses were performed, and publication bias was evaluated. Findings: The literature search retrieved 14,295 titles, and after full-text screening of 639 reports, 35 studies were included, covering eight outcomes: weight for age z-score (WAZ), height for age z-score (HAZ), BMI for age z-scores (BMIZ), overweight, underweight, stunting, wasting, and rapid weight gain. In middle-income countries, higher maternal education is significantly associated with elevated WAZ (MD 0.398, 95% CI 0.301-0.496) and HAZ (MD 0.388, 95% CI 0.102-0.673) in children. Similarly, in studies with low-educated population, higher maternal education is significantly linked to increased WAZ (MD 0.186, 95% CI 0.078-0.294) and HAZ (0.200, 95% CI 0.036-0.365). However, in high-income and highly educated population, this association is either absent or reversed. In high-income countries, higher maternal education is associated with a non-significant lower BMI-Z (MD -0.028, 95% CI -0.061 to 0.006). Notably, this inverse association is statistically significant in low-educated populations (MD -0.045, 95% CI -0.079 to -0.011) but not in highly educated populations (MD 0.003, 95% CI -0.093 to 0.098). Interpretation: Maternal education's association with child growth varies based on country income and education levels. Further research is needed to understand this relationship better. Funding: This study was a student thesis supported financially by Tehran University of Medical Sciences (TUMS).

Diabetes is associated with increased liver cancer incidence and mortality in adults: A report from Asia Cohort Consortium.

There has been growing evidence suggesting that diabetes may be associated with increased liver cancer risk. However, studies conducted in Asian countries are limited. This project considered data of 968,738 adults pooled from 20 cohort studies of Asia Cohort Consortium to examine the association between baseline diabetes and liver cancer incidence and mortality. Cox proportional hazard model and competing risk approach was used for pooled data. Two-stage meta-analysis across studies was also done. There were 839,194 subjects with valid data regarding liver cancer incidence (5654 liver cancer cases [48.29/100,000 person-years]), follow-up time and baseline diabetes (44,781 with diabetes [5.3%]). There were 747,198 subjects with valid data regarding liver cancer mortality (5020 liver cancer deaths [44.03/100,000 person-years]), follow-up time and baseline diabetes (43,243 with diabetes [5.8%]). Hazard ratio (HR) (95% confidence interval [95%CI]) of liver cancer diagnosis in those with vs. without baseline diabetes was 1.97 (1.79, 2.16) (p < .0001) after adjusting for baseline age, gender, body mass index, tobacco smoking, alcohol use, and heterogeneity across studies (n = 586,072; events = 4620). Baseline diabetes was associated with increased cumulative incidence of death due to liver cancer (adjusted HR (95%CI) = 1.97 (1.79, 2.18); p < .0001) (n = 595,193; events = 4110). A two-stage meta-analytic approach showed similar results. This paper adds important population-based evidence to current literature regarding the increased incidence and mortality of liver cancer in adults with diabetes. The analysis of data pooled from 20 studies of different Asian countries and the meta-analysis across studies with large number of subjects makes the results robust.

Validity and reproducibility of the PERSIAN Cohort food frequency questionnaire: assessment of major dietary patterns.

BACKGROUND: Dietary patterns, encompassing an overall view of individuals' dietary intake, are suggested as a suitable means of assessing nutrition's role in chronic disease development. The aim of this study was to evaluate the validity and reproducibility of a food frequency questionnaire (FFQ) designed for use in the Prospective Epidemiological Research Studies in IrAN (PERSIAN), by comparing major dietary patterns assessed by the FFQ with a reference method. METHODS: Study participants included men and women who enrolled in the PERSIAN Cohort Study at seven of the eighteen centers. These centers were chosen to include dietary variations observed among the different Iranian ethnic populations. Two FFQ were completed for each participant over a one-year study period (FFQ1 upon enrollment and FFQ2 at the end of the study), with 24 interviewer-administered 24-hour dietary recalls (24 h) being completed monthly in between. Spearman correlation coefficients (SCC) were used comparing FFQs 1 and 2 to the 24 h to assess validity, while FFQ1 was compared to FFQ2 to assess reproducibility of the questionnaire. RESULTS: Three major dietary patterns-Healthy, Low Protein/High Carb and Unhealthy-were identified, accounting for 70% of variance in the study population. Corrected SCC ranged from 0.31 to 0.61 in the validity and from 0.34 to 0.57 in reproducibility analyses, with the first two patterns, which accounted for over 50% of population variance, correlated at above 0.5 in both parameters, showing acceptable findings. CONCLUSIONS: The PERSIAN Cohort FFQ is suitable for identification of major dietary patterns in the populations it is used for, in order to assess diet-disease relationships.

Effectiveness of polypill for primary and secondary prevention of cardiovascular disease: a pragmatic cluster-randomised controlled trial (PolyPars).

BACKGROUND: We aimed to investigate the effectiveness of fixed-dose combination therapy (polypill) for primary and secondary prevention of major cardiovascular diseases in a typical rural setting. METHODS: The PolyPars Study is a two-arm pragmatic cluster-randomised trial nested within the PARS cohort study, including all residents aged over 50 years in the entire district in southern Iran. The 91 villages underwent random allocation into two arms: the control arm, encompassing 45 clusters, was subjected to non-pharmacological intervention (educational training on healthy lifestyle), whereas the intervention arm, comprising 46 clusters, received the non-pharmacological interventions in conjunction with a once-daily polypill tablet. This tablet comprised two antihypertensive agents, a statin and aspirin. The primary outcome was the first occurrence of major cardiovascular events defined as a composite of hospitalisation for acute coronary syndrome (non-fatal myocardial infarction and unstable angina), fatal myocardial infarction, non-fatal and fatal stroke, sudden death and heart failure. The Cox regression model, with shared frailty, was used to account for clustering effect. RESULTS: During December 2015-December 2016, a total of 4415 participants aged 50-75 years were recruited (2200 participants in the intervention arm and 2215 participants in the control arm). The overall median of follow-up duration was 4.6 years (interquartile interval 4.4-4.9). The achieved adherence rate to polypill in intervention arm was 86%. In the control group, 176 (8.0%) of 2215 participants developed primary outcome, compared with 88 (4.0%) of 2200 participants in the polypill group. We found substantial reduction in risk of primary outcome both in relative and absolute scales (HR 0.50, 95% CI 0.38 to 0.65; absolute risk reduction 4.0%, 95% CI 2.5% to 5.3%). No difference in serious adverse events was observed between the two groups. CONCLUSIONS: The fixed-dose combination therapy using polypill can safely halve the risk of major cardiovascular diseases at the population level. TRIAL REGISTRATION NUMBER: NCT03459560.

Mineral Intake and Cardiovascular Disease, Cancer, and All-Cause Mortality: Findings from the Golestan Cohort Study.

Associations between mineral intake and mortality in non-Western countries have not been studied adequately. This study evaluated these associations in the Golestan Cohort Study, featuring a Middle Eastern population. The mineral intake was estimated from the baseline food frequency questionnaire, adjusted by using the nutrient density method, and divided into quintiles. We used Cox proportional hazards models to estimate hazard ratios (HR) and 95% confidence intervals (CI) for the mortality. We analyzed 41,863 subjects with a mean age of 51.46 ± 8.73 years at the baseline. During 578,694 person-years of follow-up (median: 14.1 Years), 7217 deaths were recorded. Dietary calcium intake was inversely associated with the all-cause mortality (HRQ5 vs. Q1 = 0.91, 95%CI = 0.85-0.99). We observed significant associations between calcium (HRQ5 vs. Q1 = 0.82, 95% CI = 0.73-0.93), copper (HRQ5 vs. Q1 = 1.11, 95% CI = 0.99-1.26), and selenium intake (HRQ5 vs. Q1 = 1.14, 95% CI = 1.01-1.29) and CVD mortality. Dietary phosphorus (HRQ5 vs. Q1 = 0.81, 95%CI = 0.69-0.96) and copper intake (HRQ5 vs. Q1 = 0.84, 95%CI = 0.71-0.99) were inversely associated with cancer mortality. In this study within a Middle Eastern population, a higher dietary intake of calcium exhibited an inverse association with all-cause mortality. Furthermore, nuanced associations were observed in the cause-specific mortality, suggesting potential avenues for dietary interventions and emphasizing the importance of considering dietary factors in public health strategies.

Prevalence of metabolically healthy obesity and healthy overweight and the associated factors in southern Iran: A population-based cross-sectional study.

Background and Aims: Obesity is considered a major growing threat to public health which could negatively affect the quality of life. The current cross-sectional study was conducted to investigate the population-based prevalence of metabolically healthy obesity (MHO) and healthy overweight (MHOW) and associated factors in southern Iran. Methods: Baseline data from the Pars Cohort Study was analyzed. Metabolically healthy participants were identified based on the definition of the American Heart Association for the metabolic syndrome. The prevalence of MHOW and MHO and their 95% confidence intervals were estimated. Poisson regression was applied for the calculation of prevalence ratios (PRs). Results: Gender- and age-standardized prevalences of MHOW and MHO were 6.3% (6.0%-6.6%) and 2.3% (2.1%-2.5%), respectively. The following factors were associated with being MHOW compared with those with normal weight: Being younger, female gender (1.31, 1.20-1.43), higher socioeconomic status, being noncurrent cigarette smoker (1.27, 1.11-1.45), low level of physical activity (1.14, 1.03-1.25), having normal overweight during adolescence, and overweight (1.35, 1.24-1.48) or obesity (1.68, 1.53-1.86) during young adulthood. We also found strong associations between MHO and younger age groups, female gender (2.87, 2.40-3.42), being married (1.57, 1.08-2.27), Fars ethnicity (1.25, 1.10-1.43), higher socioeconomic status, ever use of tobacco (1.14, 1.00-1.30), never use of opium (1.85, 1.19-2.86), lower physical activity (1.45, 1.20-1.72), being normal weight in 15-year body pictogram and being overweight (1.87, 1.59-2.20) or obese (3.20, 2.74-3.72) in 30-year body pictogram when considering those with normal weight or MHO. Conclusion: Potentially modifiable factors including physical activity should be more emphasized. Furthermore, our study issued that it would be more reasonable that the prevention of unhealthy obesity be initiated before the development of MHO, where there are more protective factors and they could be more effective.

Dental health and lung cancer risk in the Golestan Cohort Study.

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.

The effects of intermittent fasting diet in comparison with low-calorie diet on lipid profile, glycemic status, and liver fibrosis in patients with non-alcoholic fatty liver (NAFLD): a study protocol for a randomized controlled clinical trial.

INTRODUCTION: Non-alcoholic fatty liver disease (NAFLD) is a common liver disease characterized by an increase in fat in liver cells. The outbreak of NAFLD is estimated to be 32.4% worldwide, with higher rates in Asia and Iran. Nutritional factors such as excessive calorie intake, high fructose intake, copper deficiency, and increased iron intake play an important role in NAFLD. Since there is no specific treatment for NAFLD, intermittent fasting (IF) diet has been suggested as an alternative treatment for obesity and related complications. Previous studies showed the potential positive effects of IF on metabolic health and the reduction of oxidative stress in NAFLD. This randomized controlled trial (RCT) will be aimed to examine the effect of the IF diet in comparison with a low-calorie diet (LCD) on lipid profile, glycemic status, and liver fibrosis in patients with NAFLD. METHODS AND ANALYSIS: This is a parallel randomized clinical trial conducted on 52 overweight and obese patients with NAFLD. Participants will be randomly assigned to receive either 16:8 IF (fasting from 8 P.M. to 12 P.M. the next day) or a low-calorie (55% carbohydrate- 30% fat, 15% protein) diet for 12 weeks. Anthropometric measurements, liver assessments, and metabolic evaluations will be assessed before and after the intervention. Primary outcomes include liver steatosis and fibrosis, while secondary outcomes include liver function enzymes, insulin resistance, lipid profile, and anthropometric measurements. DISCUSSION: Since obesity and insulin resistance are the most important risk factors of NAFLD, and there is no treatment for it, it seems that lifestyle changes such as low caloric diet like IF and exercise can improve lipid metabolism and liver enzymes. TRIAL REGISTRATION: Iranian registry of clinical trials (IRCT20170202032367N5).

Prevalence and determinants of opioid use disorder among long-term opiate users in Golestan Cohort Study.

BACKGROUND: Number of opiate users worldwide has doubled over the past decade, but not all of them are diagnosed with opioid use disorder. We aimed to identify the prevalence and risk factors for OUD after ten years of follow-up. METHODS: Among 8,500 chronic opiate users at Golestan Cohort Study baseline (2004-2008), we recalled a random sample of 451 subjects in 2017. We used three questionnaires: a questionnaire about current opiate use including type and route of use, the drug use disorder section of the Composite International Diagnostic Interview lifetime version, and the validated Kessler10 questionnaire. We defined opioid use disorder and its severity based on the DSM-5 criteria and used a cutoff of 12 on Kessler10 questionnaire to define psychological distress. RESULTS: Mean age was 61.2 ± 6.6 years (84.7% males) and 58% were diagnosed with opioid use disorder. Starting opiate use at an early age and living in underprivileged conditions were risk factors of opioid use disorder. Individuals with opioid use disorder were twice likely to have psychological distress (OR = 2.25; 95%CI: 1.44-3.52) than the users without it. In multivariate regression, former and current opiate dose and oral use of opiates were independently associated with opioid use disorder. Each ten gram per week increase in opiate dose during the study period almost tripled the odds of opioid use disorder (OR = 3.18; 95%CI: 1.79-5.63). CONCLUSIONS: Chronic opiate use led to clinical opioid use disorder in more than half of the users, and this disorder was associated with psychological distress, increasing its physical and mental burden in high-risk groups.

Polypharmacy and pattern of medication use among patients with gastroesophageal reflux disease: results from Pars Cohort study.

BACKGROUND: Gastroesophageal Reflux Disease (GERD) is a common chronic condition. Its chronic nature may affect the pattern of medication use. This study aimed to investigate the prevalence, associated factors, and patterns of polypharmacy and medication use among GERD patients in southwestern Iran. METHODS: We used data from the Pars Cohort Study. We classified drugs using the Anatomical Therapeutic Chemical classification system. The Lexicomp® database was used to assess potential drug-drug interactions. Multivariable Poisson regression was applied. Adjusted prevalence ratio (PR) and its 95% confidence interval (CI) were estimated. RESULTS: A total of 9262 participants were included. Among 2,325 patients with GERD, age-standardized prevalence of polypharmacy was 9.5% (95% CI: 7.5%, 11.6%) in males, and 19.3% (95% CI: 17.2%, 21.4%) in females. The PR of experiencing Polypharmacy by GERD patients compared to non-GERD patients was 1.82 (95% CI: 1.61, 2.05%). Multimorbidity (PR: 3.33; CI: 2.66, 4.15), gender (PR: 1.68; CI: 1.30, 2.18), and metabolic syndrome (PR: 1.77; CI: 1.45, 2.15) were associated with polypharmacy among GERD patients. Drugs for acid-related disorders were the most common used drugs among men, women and elders. We found that 13.9%, 4.2%, and 1.1% of GERD patients had type C, D and X drug interactions, respectively. CONCLUSION: GERD is correlated with a higher prevalence of polypharmacy. Among GERD patients, females, those with multi-morbidities, and those with metabolic syndrome may be affected more by polypharmacy. Considering the fairly high rate of interactions identified, a review of the medication list is essential when approaching GERD patients, and physicians must check for medications that may worsen GERD.

Liver fibrosis in pars cohort study: A large-scale study on the prevalence and correlated factors.

BACKGROUNDS AND STUDY AIMS: The fibrosis-4 (FIB-4) is a non-invasive scoring system for estimating liver fibrosis severity as a biomarker of chronic liver disease. We aimed to estimate the prevalence and severity of chronic liver disease at the community level using FIB-4. PATIENTS AND METHODS: This cross-sectional study was conducted using the Pars Cohort database collected in Valashar, Fars province, Iran. Participants were divided into three groups based on their FIB-4 scores: low risk of liver fibrosis (FIB < 1.45), intermediate cases (1.45 ≤ FIB-4 ≤ 3.25), and high risk of liver fibrosis (FIB-4 > 3.25). RESULTS: In total, 9269 individuals with a mean age of 52.65 years were enrolled in the study, of which 4278 (46.2 %) were male. Among all participants, 7853 (84.7 %) were in the low-risk, and 65 (0.7 %) were in the high-risk groups. In the final ordinal regression model, male gender, being a farmer or rancher, living in rural areas, history of opioid use, history of jaundice, no history of diabetes, history of depression, and positive HBs Ag were independently associated with higher FIB-4 scores. CONCLUSION: Our study revealed that males, individuals residing in rural areas, and those engaged in farming and ranching occupations face a heightened risk of liver fibrosis. These findings emphasize the need for future programs for early detection and effective management of liver fibrosis in these at-risk populations.

Higher intakes of fiber, total vegetables, and fruits may attenuate the risk of all-cause and cause-specific mortality: findings from a large prospective cohort study.

BACKGROUND: Although studies have reported an inverse association between fruits, vegetables, and fiber consumption and all-cause and cause-specific mortality, the issue remains incompletely defined in the Middle Eastern population. AIMS: The current study aimed to investigate the association between dietary fiber, fruit, and vegetable intake and all-cause and cause-specific mortality. METHODS: A total of 48632 participants (mean age = 52years), 57.5% (n = 27974) women and 42.5% (n = 20658) men, were recruited from an ongoing large-scale prospective cohort study (the Golestan Cohort Study (GCS)), in the north of Iran. Using a validated semi-quantitative 116-item food questionnaire, dietary intakes were collected. Hazard ratios (HRs) and 95% confidence intervals (95%CIs) of all-cause and cause-specific mortality were reported. RESULTS: After approximately 14 years of follow-up, 10,774 deaths were recorded. In the fully adjusted model, compared to those in the lowest quintile of intake, those in the second and third quintiles of dietary fiber intake had a 7%-10% reduction in risk of all-cause mortality, and a 15%-17% reduction in the risk of mortality from other causes. Increasing consumption of fruits was also associated with a decreased risk of mortality for all-cause mortality by 9%-11%, and all cancer by 15-20%. Further, those in the third and fourth quintiles of vegetables intake had 11%-12% lower risk for CVD mortality. DISCUSSION: The results from the GCS further support the current recommendations on following a healthy diet containing proper amounts of fiber, vegetables, and fruits, as health-protective dietary items. CONCLUSIONS: Higher intake of dietary fiber, fruits, and vegetables has the potential to reduce both overall and cause-specific mortality rates. However, additional cohort studies with larger sample size and long-term follow-up durations are required to establish these findings.

A Single nucleotide polymorphism in the ALDH2 gene modifies the risk of esophageal squamous cell carcinoma in BRCA2 p.K3326* carriers.

Esophageal squamous cell carcinoma (ESCC) has a very high incidence rate in northeastern Iran. Our team previously reported the BReast CAncer gene 2 (BRCA2) p.K3326* mutation as a moderately penetrant ESCC susceptibility variant in northern Iran (odds ratio (OR) = 3.64, 95% confidence interval (CI) = 1.74-7.59, P = 0.0003). Recently, it has been reported that aldehydes can induce BRCA2 haploinsufficiency in cells with a heterozygous pathogenic BRCA2 mutation and predispose them to carcinogenic effects. Based on this observation, we speculate that dysfunctional variants in Aldehyde Dehydrogenase 2 Family Member (ALDH2) may result in aldehyde-induced BRCA2 haploinsufficiency and increase cancer risk in BRCA2 mutation carriers. In support of this hypothesis, our team recently reported the breast cancer risk modifying effect of an ALDH2 common polymorphism, rs10744777, among Polish carriers of the BRCA2 p.K3326* mutation. In the current case-control study, we aimed to investigate the ESCC risk modifying effect of this ALDH2 polymorphism among BRCA2 p.K3326* mutation carriers. We assessed the interaction between the ALDH2 rs10744777 polymorphism and BRCA2 p.K3326* mutation in ESCC risk by genotyping this ALDH2 variant in the germline DNA of 746 ESCC cases and 1,373 controls from northern Iran who were previously genotyped for the BRCA2 p.K3326* mutation. Among a total of 464 individuals with TT genotype of the ALDH2 rs10744777 polymorphism, which is associated with lower ALDH2 expression, we found 9 of 164 cases versus 3 of 300 controls who carried the BRCA2 p.K3326* variant (OR = 5.66, 95% CI = 1.22-26.2, P = 0.018). This finding supports our hypothesis that the ALDH2-rs10744777 TT genotype may be a significant risk modifier of ESCC in individuals with a BRCA2 p.K3326* mutation.

Incident cancers attributable to using opium and smoking cigarettes in the Golestan cohort study.

Background: Opium consumption has recently been identified as a carcinogen, but the impact of opium use on cancer burden is unknown. We aimed to evaluate the fraction of cancers that could be attributed to opium use alone and in combination with cigarette smoking in a region where opium is widely used. Methods: 50,045 Iranian adults were recruited to this prospective cohort study between 2004 and 2008 and were followed through January 2022. We assessed the association between using opium and/or cigarette smoking and various cancers using proportional hazards regression models. We then calculated population attributable fractions (PAFs) for all cancers and for groups of cancers causally linked to opium and cigarette smoking. Findings: Of the total participants, 8% only used opium, 8.3% only smoked cigarettes, and 9% used both substances. During a median 14 years of follow-up, 2195 individuals were diagnosed with cancer, including 215 opium-related cancers (lung, larynx, and bladder) and 1609 tobacco-related cancers (20 types). Opium use alone was estimated to cause 35% (95% CI: 26%-45%) of opium-related cancers, while smoking cigarettes alone was estimated to cause 9% (6%-12%) of tobacco-related cancers in this population. Using opium and/or cigarettes was estimated to cause 13% (9%-16%) of all cancers, 58% (49%-66%) of opium-related cancers, and 15% (11%-18%) of tobacco-related cancers. Moreover, joint exposure to opium and cigarettes had the greatest impact on cancers of the larynx, pharynx, lung, and bladder, with PAFs ranging from 50% to 77%. Interpretation: Using opium and smoking cigarettes account for a large proportion of cancers in this population. To reduce the cancer burden, prevention policies should aim to decrease the use of both substances through public awareness campaigns and interventional efforts. Funding: The Golestan Cohort Study work was funded by the Tehran University of Medical Sciences, Cancer Research UK, U.S. National Cancer Institute, International Agency for Research on Cancer. The presented analysis was supported by the International HundredK+ Cohorts Consortium (IHCC).

Smoke exposure associated with higher urinary benzene biomarker muconic acid (MUCA) in Golestan Cohort Study participants.

Background. Benzene is a known human carcinogen. Human exposure to benzene can be assessed by measuring trans, trans-muconic acid (MUCA) in urine. Golestan Province in northeastern Iran has been reported to have high incidence of esophageal cancer linked to the use of tobacco products. This manuscript evaluates the urinary MUCA concentrations among the participants of the Golestan Cohort Study (GCS).Methods. We analyzed MUCA concentration in 177 GCS participants' urine samples and performed nonparametric pairwise multiple comparisons to determine statistically significant difference among six different product use groups. Mixed effects model was fitted on 22 participants who exclusively smoked cigarette and 51 participants who were classified as nonusers. The urinary MUCA data were collected at the baseline and approximately five years later, and intraclass correlation coefficient (ICC) was calculated from the model.Results. Compared with nonusers, tobacco smoking was associated with higher urinary MUCA concentrations. Based on the nonparametric test of pairwise multiple comparisons, MUCA concentrations among participants who smoked combusted tobacco products were statistically significantly higher compared to nonusers. Urinary MUCA collected five years apart from the same individuals showed moderate reliability (ICC = 0.41), which was expected given the relatively short half-life (∼6 h) of MUCA.Conclusion. Our study revealed that tobacco smoke was positively associated with increased levels of urinary MUCA concentration, indicating that it is a significant source of benzene exposure among GCS participants.

Exposure to polycyclic aromatic hydrocarbons, volatile organic compounds, and tobacco-specific nitrosamines and incidence of esophageal cancer.

BACKGROUND: Studying carcinogens in tobacco and non-tobacco sources may be key to understanding the pathogenesis and geographic distribution of esophageal cancer. METHODS: Golestan Cohort Study (GCS) has been conducted since 2004 in a region with high rates of esophageal squamous cell carcinoma (ESCC). For this nested study, the cases comprised of all incident cases by Jan 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 (PAHs), volatile organic compounds (VOCs), and tobacco-specific nitrosamines (TSNAs). We used conditional logistic regression to calculate odds ratios (OR) and 95% confidence intervals (95%CI) for associations between the 90th versus the 10th percentiles of the biomarker concentrations and incident ESCC. RESULTS: Among individuals who did not currently use tobacco (148 cases/163 controls), two acrolein metabolites, two acrylonitrile metabolites, one propylene oxide metabolite and one 1,3-butadiene metabolite were significantly associated with incident ESCC (adjusted ORs between 1.8 and 4.3). Among tobacco users (57 cases/63 controls), metabolites of two other VOCs (styrene and xylene) were associated with ESCC (ORs= 6.2 and 9.0). In tobacco users, two TSNAs (NNN and N'-Nitrosoanatabine) were also associated with ESCC. Suggestive associations were seen with some PAHs (especially 2-hydroxynaphthalene) in non-users of tobacco products and other TSNAs 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.

Association between dietary glycemic index and non-alcoholic fatty liver disease in patients with type 2 diabetes mellitus.

Objective: Managing dietary glycemic index (GI) deserves further attention in the interplay between non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus (T2DM). This study aimed to evaluate the relationship between dietary GI and the odds of NAFLD in patients with T2DM. Methods: A cross-sectional study was carried out between April 2021 and February 2022, including 200 participants with T2DM aged 18-70 years, of which 133 had NAFLD and 67 were in the non-NAFLD group. Cardiometabolic parameters were analyzed using standard biochemical kits and dietary intake was assessed using a validated food frequency questionnaire. Binary logistic regression was applied to explore odds ratios (ORs) and 95% confidence intervals (CIs) for NAFLD according to tertiles of dietary GI. Results: Highest vs. lowest tertile (< 57 vs. > 60.89) of energy-adjusted GI was not associated with the odds of having NAFLD (OR 1.25, 95% CI = 0.6-2.57; P-trend = 0.54) in the crude model. However, there was an OR of 3.24 (95% CI = 1.03-10.15) accompanied by a significant trend (P-trend = 0.04) after full control for potential confounders (age, gender, smoking status, duration of diabetes, physical activity, waist circumference, HbA1c, triglycerides, total cholesterol, dietary intake of total carbohydrates, simple carbohydrates, fat, and protein). Conclusion: High dietary GI is associated with increased odds of NAFLD in subjects with T2DM. However, interventional and longitudinal cohort studies are required to confirm these findings.

Validity and reproducibility of a food frequency questionnaire assessing food group intake in the PERSIAN Cohort Study.

Purpose: A semi-quantitative food frequency questionnaire (FFQ) was developed for use in the Prospective Epidemiological Research Studies in IrAN (PERSIAN Cohort), investigating non-communicable disease risk factors. This study aimed to assess the validity and reproducibility of this FFQ, through food group intake. Methods: Participants, recruited from seven PERSIAN cohort centers, completed the FFQ at the beginning of the study (FFQ1) and at the end (FFQ2), with a 12-month interval in between, during which two 24-h dietary recalls (24 h) were completed each month. Correlation coefficients of the median intake of food groups recorded by the FFQs were compared to those of the 24 h to assess validity, and the two FFQs were compared to assess reproducibility of findings. Results: Overall, data from 978 participants were included in this validation analysis. Of the 26 food groups assessed, Tea, Sugars, Whole/Refined Grains, and Solid Fats/Oils, had the strongest correlations (0.6-0.79), while Red Meat, Chicken and Eggs showed moderate correlations (0.42-0.59). The weakest correlations observed belonged to Fresh fruit Juice and Other Meats (0.23-0.32). Reproducibility was assessed among those who completed both FFQ1 and FFQ2 (n = 848), revealing moderate to strong correlations in all food groups, ranging from 0.42 in Legumes to 0.72 in both Sugar and Sweetened Drinks. Conclusion: The PERSIAN Cohort FFQ is appropriate to rank individuals based on food group intake.

Population attributable proportion and number of cancer cases attributed to potentially modifiable risk factors in Iran in 2020.

In the current study, we aimed to calculate the fraction of cancer attributable to modifiable risk factors in Iran in 2020. Population attributable fractions (PAFs) were calculated for established cancer risk factors using three data sources: the national cancer incidence reports, relative risks extracted from global and national meta-analyses, and exposure prevalence from national/subnational population-based surveys. In addition to overall cancers, the PAFs were estimated separately for each cancer site among men and women. Overall, 32.6% of cancers in 2020 in Iran were attributable to known risk factors. The PAF in men (40.2%) was twice as high as in women (21.1%). Cigarette smoking (15.4%), being overweight (5.0%), opium use (3.9%) and H. pylori infection (3.8%) were the leading causes of cancers. For men, the highest PAFs belonged to cigarette smoking (26.3%), opium use (6.8%) and being overweight (3.1%), while for women, the highest PAFs belonged to being overweight (7.2%), H. pylori infection (2.7%) and cigarette smoking (2.7%). Among Iranian men and women, the PAFs of waterpipe smoking were 2% and 0.9%, respectively. A third of incident cancers in Iran are due to modifiable exposures, mainly cigarette smoking, being overweight, and H. pylori infection. Opium consumption and waterpipe smoking collectively accounted for 8.8% of cancer occurrence in men and 1.3% in women in Iran. These emerging risk factors should be taken into consideration in future PAF studies.

Association Between Incident Type 2 Diabetes and Opium Use: Mediation by Body Mass and Adiposity.

Opiates can affect glucose metabolism and obesity, but no large prospective study (to our knowledge) has investigated the association between long-term opium use, body mass index (BMI; weight (kg)/height (m)2), and incident type 2 diabetes mellitus (T2DM). We analyzed prospective data from 50,045 Golestan Cohort Study participants in Iran (enrollment: 2004-2008). After excluding participants with preexisting diseases, including diabetes, we used adjusted Poisson regression models to estimate incidence rate ratios (IRRs) and 95% confidence intervals (CIs) for T2DM in opium users compared with nonusers, using mediation analysis to assess the BMI-mediated association of opium use with incident T2DM. Of 40,083 included participants (mean age = 51.4 (standard deviation, 8.8) years; 56% female), 16% were opium users (median duration of use, 10 (interquartile range), 4-20) years). During follow-up (until January 2020), 5,342 incident T2DM cases were recorded, including 8.5% of opium users and 14.2% of nonusers. Opium use was associated with an overall decrease in incident T2DM (IRR = 0.83, 95% CI: 0.75, 0.92), with a significant dose-response association. Most (84.3%) of this association was mediated by low BMI or waist circumference, and opium use did not have a direct association with incident T2DM (IRR = 0.97, 95% CI: 0.87, 1.08). Long-term opium use was associated with lower incidence of T2DM, which was mediated by low body mass and adiposity.