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.

Mortality after multivitamin supplementation: Nearly 35-year follow-up of the randomized Linxian Dysplasia Nutrition Intervention Trial.

BACKGROUND: The objective of this study was to update the association between multivitamin supplementation and total or cause-specific mortality in a population with a high prevalence of undernutrition in China. METHODS: The Linxian Dysplasia Nutrition Intervention Trial was a randomized, double-blind, placebo-controlled trial in which 3318 persons aged 40-69 years with esophageal squamous dysplasia were assigned to receive daily multivitamin supplementation or a placebo for 6 years and were followed for 29 years. The primary outcome was esophageal/gastric cardia cancer mortality. The data were analyzed with Cox proportional hazards regression models. Subgroup analyses were performed by common characteristics such as age and gender. RESULTS: The cumulative total mortality was 83.5%. Multivitamin supplementation did not affect total or cause-specific mortality in the participants as a whole (hazard ratio [HR], 0.96; 95% confidence interval [CI], 0.89-1.03). Subgroup analyses showed that no association between multivitamin supplementation and all-cause mortality was observed in men (HR, 0.90; 95% CI, 0.81-1.01), women (HR, 1.01; 95% CI, 0.91-1.12), younger participants (HR, 0.97; 95% CI, 0.87-1.08), or older participants (HR, 0.94; 95% CI, 0.85-1.04). Significant reductions in heart disease mortality (HR, 0.64; 95% CI, 0.47-0.87) and cerebrovascular disease mortality (HR, 0.74; 95% CI, 0.56-1.00) were seen in older men. In a subgroup of younger men and a subgroup of moderate or severe dysplasia, subjects receiving multivitamin supplementation had a lower risk of esophageal/cardia cancer mortality (HR for younger men, 0.76; 95% CI, 0.58-0.99; HR for moderate or severe dysplasia, 0.76; 95% CI, 0.58-1.00). No association between multivitamin supplementation and any cause-specific mortality was observed in a mild dysplasia population. CONCLUSIONS: Multivitamin supplementation in a population with esophageal squamous dysplasia was not associated with the risk of total mortality in the 35-year follow-up of this randomized controlled trial. In light of this and previous trials, multivitamin supplements should be used thoughtfully to improve health status of populations with esophageal squamous dysplasia. LAY SUMMARY: Multivitamin supplementation is common, yet its effect on mortality is unclear. The aim of this study was to update the long-term effects of multivitamin supplementation on total and cause-specific mortality during nearly 35 years of follow-up in the Linxian Dysplasia Nutrition Intervention Trial in China. Multivitamin supplementation in a population with esophageal squamous dysplasia was not associated with the risk of total mortality in the 35-year follow-up of this randomized controlled trial, and this indicates that multivitamin supplements should be used thoughtfully to improve health status.

Lead poisoning among asymptomatic individuals with a long-term history of opiate use in Golestan Cohort Study.

BACKGROUND: Recent reports of lead poisoning suggest that people who use opium may be exposed to high amounts of lead. Here, we investigate the association between opium use and blood lead levels (BLL) in a population-based cohort study. METHODS: In 2017, we studied a random sample of 410 people who currently (both within the past year and the past month) used opium and 104 who did not from participants of the Golestan Cohort Study in northeast Iran. Participants were stratified by sex and tobacco use history, completed a comprehensive opiate and tobacco use questionnaire and provided blood. BLL was measured by Lead Care® II Blood Lead Test Kit, validated by inductively coupled plasma triple quadrupole mass spectrometry. BLL was categorized as "<5 µg/dL", "elevated" (5-10 µg/dL), "high" (10-50 µg/dL), and "very high" (above 50 µg/dL). To assess the association between BLL categories and opiate use, route of consumption and weekly use, we used ordered logistic regression models, and report OR (odds ratio) and 95% CI (confidence interval) adjusted for age, sex, place of residence, education, occupation, household fuel type, and tobacco use. RESULTS: In the cohort, participants used only raw (teriak) or refined (shireh) opium, which were smoked (45%, n = 184), taken orally (46%, n = 189), or both (9%, n = 37), for a mean duration of 24.2 (standard deviation: 11.6) years. The median BLL was significantly higher in people who currently used opium (11.4 µg/dL; IQR: 5.2-23.4) compared with those who did not (2.3 µg/dL; IQR: 2.3-4.2), and the highest median BLL was seen in oral use (21.7 µg/dL; IQR: 12.1-34.1). The BLL was <5 µg/dL among 79.8% of people with no opiate use, compared with only 22.7% in those using opium. BLL was elevated in 21.7%, high in 50.5% and very high in 5.1% of people using opium. About 95% of those with oral (180/189) or dual use (35/37) and 55% (102/184) of those who smoked opium had levels of blood lead above 5 µg/dL. The OR for the association between any opium use and each unit of increase in BLL category was 10.5 (95%CI: 5.8-19.1), and oral use of opium was a very strong predictor of increasing BLL category (OR=74.1; 95%CI: 35.1-156.3). This odds ratio was 38.8 (95%CI: 15.9-95.1) for dual use and 4.9 (95%CI: 2.6-9.1) for opium smoking. There was an independent dose-response association between average weekly dose and BLL among people using opium, overall and when stratified by route of use. CONCLUSION: Our results indicate that regular use of lead-adulterated opium can expose individuals to high levels of lead, which may contribute to mortality and cancer risks associated with long-term opium use.

Cigarette Smoking and Opium Use in Relation to the Oral Microbiota in Iran.

Cigarettes and opium contain chemicals and particulate matter that may modify the oral microbiota. This study aimed to investigate the association between cigarette and opium use with the oral microbiota. A total of 558 participants were recruited from Iran between 2011 and 2015. Individuals were categorized as never cigarette nor opium users, ever cigarette-only smokers, ever opium-only users, and ever both cigarette and opium users. Participants provided saliva samples for 16S rRNA gene sequencing. Logistic regression, microbiome regression-based kernel association test (MiRKAT), and zero-inflated beta regression models were calculated. For every increase in 10 observed amplicon sequence variants (ASVs), the odds for being a cigarette-only smoker, opium-only user, and both user compared to never users decreased by 9% (odds ratio [OR] = 0.91; 95% confidence interval [95% CI] = 0.86 to 0.97), 13% (OR = 0.87; 95% CI = 0.75 to 1.01), and 12% (OR = 0.88; 95% CI = 0.80 to 0.96), respectively. The microbial communities differed by cigarette and opium use as indicated by MiRKAT models testing the three beta-diversity matrices (P < 0.05 for all). Three genera were less likely and one genus was more likely to be detected in cigarette-only smokers or opium-only users than in never users. The relative abundance of the phylum Actinobacteria (never, 14.78%; both, 21.20%) was higher and the phyla Bacteroidetes (never, 17.63%; both, 11.62%) and Proteobacteria (never, 9.06%; both, 3.70%) were lower in users of both cigarettes and opium, while the phylum Firmicutes (never, 54.29%; opium, 65.49%) was higher in opium-only users. Cigarette and opium use was associated with lower alpha-diversity, overall oral microbiota community composition, and both the presence and relative abundance of multiple taxa. IMPORTANCE Cigarette smoking and opium use are associated with periodontal disease caused by specific bacteria such as Porphyromonas gingivalis, which suggests a link between cigarette smoking and opium use and the oral microbiota. Alterations of the oral microbiota in cigarette smokers compared to nonsmokers have been reported, but this has not been studied across diverse populations. Additionally, the association of opium use with the oral microbiota has not been investigated to date. We conducted this study to investigate differences in the oral microbiota between ever users of cigarettes only, opium only, and both cigarettes and opium and never users of cigarettes and opium in Iran. Lower alpha-diversity, distinct overall oral microbial communities, and the presence and relative abundance of multiple taxa have been found for users of cigarettes and/or opium.

Colorectal cancer in the Linxian China Nutrition Intervention Trial: Risk factors and intervention results.

BACKGROUND: Colorectal cancer (CRC) is among the most common cancers in economically developed countries and developing world. While dietary factors are associated with risk of CRC in the West and urban China, little is known about risk or protective factors in rural China. METHODS: The Linxian General Population Nutrition Intervention Trial (NIT) cohort was established over 30 years ago to test whether daily multivitamin/mineral supplements could reduce the incidence and mortality of esophageal/gastric cardia cancer. The cohort included a total of 29,553 healthy participants 40-69 years old who were randomly assigned to supplements or placebos via a 24 fractional factorial study design. We examined risk factors for the development of CRC as well as the effects of four different nutritional factors (Factor A: retinol, zinc; B: riboflavin, niacin; C: ascorbic acid, molybdenum; D: selenium, alpha-tocopherol, beta-carotene,) on CRC incidence following 5.25 years of supplementation in this randomized, placebo-controlled intervention trial. RESULTS: CRC risk increased with age and height as well as piped water usage, family history of CRC, and consumption of foods cooked in oil, eggs, and fresh fruits. No effect on CRC was seen for any of these four intervention factors tested in both genders, but CRC was reduced 37% in females who received Factor D (selenium/alpha-tocopherol/beta-carotene) (RR = 0.63, 95% CI = 0.43-0.92, P = 0.016) compared to females who did not receive Factor D. CONCLUSIONS: In this undernourished rural Chinese population, CRC risk factors in this Chinese cohort showed both similarities and differences compared to Western and urban Asian Chinese populations. Intervention results suggested a potential benefit for women supplemented with selenium/alpha-tocopherol/beta-carotene.

A prospective study of tea drinking temperature and risk of esophageal squamous cell carcinoma.

Previous studies have reported an association between hot tea drinking and risk of esophageal cancer, but no study has examined this association using prospectively and objectively measured tea drinking temperature. We examined the association of tea drinking temperature, measured both objectively and subjectively at study baseline, with future risk of esophageal squamous cell carcinoma (ESCC) in a prospective study. We measured tea drinking temperature using validated methods and collected data on several other tea drinking habits and potential confounders of interest at baseline in the Golestan Cohort Study, a population-based prospective study of 50,045 individuals aged 40-75 years, established in 2004-2008 in northeastern Iran. Study participants were followed-up for a median duration of 10.1 years (505,865 person-years). During 2004-2017, 317 new cases of ESCC were identified. The objectively measured tea temperature (HR 1.41, 95% CI 1.10-1.81; for ≥60°C vs. <60°C), reported preference for very hot tea drinking (HR 2.41, 95% CI 1.27-4.56; for "very hot" vs. "cold/lukewarm"), and reported shorter time from pouring tea to drinking (HR 1.51, 95% CI 1.01-2.26; for <2 vs. ≥6 min) were all associated with ESCC risk. In analysis of the combined effects of measured temperature and amount, compared to those who drank less than 700 ml of tea/day at <60°C, drinking 700 mL/day or more at a higher-temperature (≥60°C) was consistently associated with an about 90% increase in ESCC risk. Our results substantially strengthen the existing evidence supporting an association between hot beverage drinking and ESCC.

Potato consumption and the risk of overall and cause specific mortality in the NIH-AARP study.

BACKGROUND: Potato consumption has been hypothesized to be associated with higher risk of hypertension, diabetes, and colorectal cancer. OBJECTIVE: The aim of this study was to examine the association between potato consumption and the risk of overall and cause specific mortality in the large prospective National Institutes of Health-AARP (NIH-AARP) Study. DESIGN: The NIH-AARP study recruited 566,407 persons, aged 50-72 years in 1995-1996. We excluded subjects that reported a history of chronic disease at baseline. Potato consumption data from a validated food frequency questionnaire completed at baseline was used in Cox proportional hazard models to estimate hazard ratios (HR) and 95% confidence intervals (95% CI) for overall and cause specific mortality. Final models were adjusted for potential risk factors for mortality. RESULTS: Among 410,701 participants included in this analysis, 76,921 persons died during the 15.6 years of follow-up. Eating baked, boiled, or mashed potatoes, French fries or potato salad seven or more times per week was associated with higher risk of overall mortality, in models adjusted only for age and sex (HR C4 vs C1 = 1.17, 95%CI = 1.13, 1.21). These results were attenuated in fully adjusted models (HR C4 vs C1 = 1.02, 95%CI = 0.97, 1.06). Potato consumption was not associated with risk of mortality caused by cancer (HR C4 vs C1 = 1.04, 95%CI = 0.97, 1.11), heart disease (HR C4 vs C1 = 1.00, 95%CI = 0.93, 1.09), respiratory disease (HR C4 vs C1 = 1.16, 95%CI = 0.99, 1.37), or diabetes (HR C4 vs C1 = 0.91, 95%CI = 0.71, 1.19). We tested for an association with different preparation methods and found limited evidence for differences by preparation method. The only statistically significant association was that for French fry consumption with cancer-related mortality (HR C4 vs C1 = 1.27, 95%CI = 1.02, 1.59), a finding for which uncontrolled confounding could not be ruled out. CONCLUSION: We find little evidence that potato consumption is associated with all-cause or cause-specific mortality.

Coffee and tea drinking and risk of cancer of the urinary tract in male smokers.

PURPOSE: We evaluated the association of coffee and tea drinking with risk of the urinary tract cancer in Finnish men, with high coffee consumption, using data from the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study. METHODS: The ATBC trial conducted from 1985 to 1993 enrolled 29,133 male smokers. We used Cox proportional hazards regression models to estimate hazard ratios (HRs) and confidence intervals (CIs), using men who drank more than 0 but less than 1 cup coffee/d and tea nondrinkers as our referent group for coffee and tea analyses, respectively. RESULTS: During 472,402 person-years of follow-up, 835 incident cases of bladder cancer and 366 cases of renal cell carcinoma were ascertained. For bladder cancer, we observed no association for coffee consumption (HR ≥4 vs. >0 to <1 cups/d = 1.16, 95% CI = 0.86-1.56) and a borderline statistically significant inverse association for tea consumption (HR ≥1 vs. 0 cup/d = 0.77, 95% CI = 0.58-1.00). For renal cell carcinoma, we observed no association for coffee (HR ≥4 vs. >0 to <1 cups/d = 0.85, 95% CI = 0.55-1.32) or tea consumption (HR ≥1 vs. 0 cup/d = 1.00, 95% CI = 0.68-1.46). We found no impact of coffee preparation on coffee-cancer associations. CONCLUSIONS: Coffee drinking was not associated with urinary tract cancers risk. Further research on tea and bladder cancer is warranted.

Investigating tea temperature and content as risk factors for esophageal cancer in an endemic region of Western Kenya: Validation of a questionnaire and analysis of polycyclic aromatic hydrocarbon content.

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) is common in certain areas worldwide. One area, western Kenya, has a high risk of ESCC, including many young cases (<30 years old), but has limited prior study of potential risk factors. Thermal injury from hot food and beverages and exposure to polycyclic aromatic hydrocarbons (PAHs) have been proposed as important risk factors for ESCC in other settings. The beverage of choice in western Kenya is milky tea (chai). METHODS: Healthy individuals >18 years of age who were accompanying relatives to an endoscopy unit were recruited to participate. The preferred initial temperature of chai consumption in these adults was measured by questionnaire and digital thermometer. Comparisons of these results were assessed by kappa statistics. Concentrations of 26 selected PAHs were determined by gas chromatography/mass spectrometry in samples of 11 brands of commercial tea leaves commonly consumed in Kenya. RESULTS: Kappa values demonstrated moderate agreement between questionnaire responses and measured temperatures. The mean preferred chai temperatures were 72.1 °C overall, 72.6 °C in men (n = 78), and 70.2 °C in women (n = 22; p < 0.05). Chai temperature did not significantly differ by age or ethnic group. The PAH levels in the commercial Kenyan tea leaves were uniformly low (total PAH < 300 ng/g of leaves). CONCLUSIONS: Study participants drink chai at higher temperatures than previously reported in other high-risk ESCC regions. Chai is not, however, a source of significant PAH exposure. Very hot chai consumption should be further evaluated as a risk factor for ESCC in Kenya with the proposed questionnaire.

Individual and Combined Effects of Environmental Risk Factors for Esophageal Cancer Based on Results From the Golestan Cohort Study.

BACKGROUND & AIMS: Northeast Iran has one of the highest reported rates of esophageal squamous cell carcinoma (ESCC) worldwide. Decades of investigations in this region have identified some local habits and environmental exposures that increase risk. We analyzed data from the Golestan Cohort Study to determine the individual and combined effects of the major environmental risk factors of ESCC. METHODS: We performed a population-based cohort of 50,045 individuals, 40 to 75 years old, from urban and rural areas across Northeast Iran. Detailed data on demographics, diet, lifestyle, socioeconomic status, temperature of drinking beverages, and different exposures were collected using validated methods, questionnaires, and physical examinations, from 2004 through 2008. Participants were followed from the date of enrollment to the date of first diagnosis of esophageal cancer, date of death from other causes, or date of last follow-up, through December 31, 2017. Proportional hazards regression models were used to estimate hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) for the association between different exposures and ESCC. RESULTS: During an average 10 years of follow-up, 317 participants developed ESCC. Opium smoking (HR 1.85; 95% CI 1.18-2.90), drinking hot tea (≥60°C) (HR 1.60; 95% CI 1.15-2.22), low intake of fruits (HR 1.48; 95% CI 1.07-2.05) and vegetables (HR 1.62; 95% CI 1.03-2.56), excessive tooth loss (HR 1.66; 95% CI 1.04-2.64), drinking unpiped water (HR 2.04; 95% CI 1.09-3.81), and exposure to indoor air pollution (HR 1.57; 95% CI 1.08-2.29) were significantly associated with increased risk of ESCC, in a dose-dependent manner. Combined exposure to these risk factors was associated with a stepwise increase in the risk of developing ESCC, reaching a more than 7-fold increase in risk in the highest category. Approximately 75% of the ESCC cases in this region can be attributed to a combination of the identified exposures. CONCLUSIONS: Analysis of data from the Golestan Cohort Study in Iran identified multiple risk factors for ESCC in this population. Our findings support the hypothesis that the high rates of ESCC are due to a combination of factors, including thermal injury (from hot tea), exposure to polycyclic aromatic hydrocarbons (from opium and indoor air pollution), and nutrient-deficient diets. We also associated ESCC risk with exposure to unpiped water and tooth loss.

Association of tooth loss with liver cancer incidence and chronic liver disease mortality in a rural Chinese population.

BACKGROUND: Tooth loss has been reported to be associated with the risk of liver cancer in several prior studies in economically advantaged countries. Whether this relationship is also evident in economically disadvantaged populations is not known. METHODS: We analyzed data from the Nutrition Intervention Trials, two randomized placebo-controlled trials of vitamin/mineral supplementation in Linxian, China. Participants who reported having lost permanent teeth were examined to determine the number of teeth remaining. In the 30-year follow-up period, 329 liver cancers were diagnosed and 368 chronic liver disease deaths occurred. Tooth loss was categorized based on loess smoothed age-specific predicted quartiles. Cox proportional hazards regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the two outcomes. RESULTS: Overall, persons in the highest quartile of age-specific tooth loss had an increased risk of liver cancer (HR = 1.27, 95%CI: 0.96, 1.67) which was not statistically significant. Results varied by sex and body mass index (BMI), however. Women in the highest quartile of age-specific tooth loss had a significantly increased risk (HR = 1.64, 95%CI: 1.04, 2.59), while men did not (HR = 1.08, 95%CI = 0.75, 1.57), and persons with a BMI > 23.0 kg/m2 (HR = 1.71, 95%CI: 1.00, 2.92) had a significantly increased risk, while persons with a BMI <23.0 kg/m2 did not (HR = 1.14, 95%CI: 0.82, 1.5). No relationships with chronic liver disease mortality were observed. CONCLUSIONS: In a rural, economically disadvantaged population, persons with the highest levels of age-specific tooth loss had an increased risk of liver cancer. The results, which were stronger among women and persons with greater BMI, suggest that periodontal disease may increase risk of liver cancer.

Effects of Nutrition Intervention on Total and Cancer Mortality: 25-Year Post-trial Follow-up of the 5.25-Year Linxian Nutrition Intervention Trial.

Background: A beneficial effect of supplementation with selenium, vitamin E, and beta-carotene was observed on total and cancer mortality in a Chinese population, and it endured for 10 years postintervention, but longer durability is unknown. Methods: A randomized, double-blind, placebo-controlled trial was conducted in Linxian, China, from 1986 to 1991; 29 584 residents age 40 to 69 years received daily supplementations based on a factorial design: Factors A (retinol/zinc), B (riboflavin/niacin), C (vitamin C/molybdenum), and/or D (selenium/vitamin E/beta-carotene), or placebo for 5.25 years, and followed for up 25 years. Hazard ratios (HRs) and 95% confidence intervals (CIs) for the intervention effects on mortalities were estimated using Cox proportional hazards models. Results: Through 2016, the interventions showed no effect on total mortality. The previously reported protective effect of Factor D against total mortality was lost 10 years postintervention. The protective effect of Factor D for gastric cancer was attenuated (HR = 0.93, 95% CI = 0.85 to 1.01), but a newly apparent protective effect against esophageal cancer was found for Factor B (HR = 0.92, 95% CI = 0.85 to 1.00, two-sided P = .04). Other protective/adverse associations were observed for cause-specific mortalities. Protective effects were found in people younger than age 55 years at baseline against non-upper gastrointestinal cancer death for Factor A (HR = 0.80, 95% CI = 0.69 to 0.92) and against death from stroke for Factor C (HR = 0.89, 95% CI = 0.82 to 0.96). In contrast, increased risk of esophageal cancer was found when the intervention began after age 55 years for Factors C (HR = 1.16, 95% CI = 1.04 to 1.30) and D (HR = 1.20, 95% CI = 1.07 to 1.34). Conclusions: Multiyear nutrition intervention is unlikely to have a meaningful effect on mortality more than a decade after supplementation ends, even in a nutritionally deprived population. Whether sustained or repeat intervention would provide longer effects needs further investigation.

Cross sectional study of serum selenium concentration and esophageal squamous dysplasia in western Kenya.

BACKGROUND: Low serum selenium status has been associated with increased risk of esophageal squamous cell carcinoma (ESCC). East Africa is a region of high ESCC incidence and is known to have low soil selenium levels, but this association has not previously been evaluated. In this study we assessed the association of serum selenium concentration and the prevalence of esophageal squamous dysplasia (ESD), the precursor lesion of ESCC, in a cross-sectional study of subjects from Bomet, Kenya. METHODS: 294 asymptomatic adult residents of Bomet, Kenya completed questionnaires and underwent endoscopy with Lugol's iodine staining and biopsy for detection of ESD. Serum selenium concentrations were measured by instrumental neutron activation analysis. Odds ratios (OR) and confidence intervals (95% CI) for associations between serum selenium and ESD were calculated using unconditional logistic regression. RESULTS: The mean serum selenium concentration was 85.5 (±28.3) µg/L. Forty-two ESD cases were identified (14% of those screened), including 5 (12%) in selenium quartile 1 (Q1), 5 (12%) in Q2, 15 (36%) in Q3, and 17 (40%) in Q4. Higher serum selenium was associated with prevalence of ESD (Q4 vs Q1: OR: 3.03; 95% CI: 1.05-8.74) and this association remained after adjusting for potential confounders (Q4 vs Q1: OR: 3.87; 95% CI: 1.06-14.19). CONCLUSION: This is the first study to evaluate the association of serum selenium concentration and esophageal squamous dysplasia in an African population at high risk for ESCC. We found a positive association between higher serum selenium concentration and prevalence of ESD, an association contrary to our original hypothesis. Further work is needed to better understand the role of selenium in the etiology of ESCC in this region, and to develop effective ESCC prevention and control strategies.

Toenail mineral concentration and risk of esophageal squamous cell carcinoma, results from the Golestan Cohort Study.

Studies conducted in China linked selenium deficiency to higher risk of esophageal squamous cell carcinoma (ESCC), but this has not been widely tested outside that selenium-deficient region. The aim of this study was to investigate the association between selenium and other mineral concentrations in toenails and risk of ESCC in a region with high incidence rates. In this nested case-control study, we identified 222 cases of ESCC from the Golestan Cohort Study, Iran, which has followed up 50,045 participants since enrollment (2004-2008). We randomly selected one control for each case matched by age and sex, using incidence density sampling. We used toenail samples collected at baseline to measure the concentration of selenium, zinc, chromium, mercury, and scandium using instrumental neutron activation analysis. Multivariate adjusted logistic regression models were used to estimate odds ratios (OR) and 95% confidence intervals. Median nail selenium, zinc, chromium, and mercury levels were 1.01, 74.59, 0.77, and 0.018 µg/g in cases and 1.02, 75.71, 0.71, and 0.023 µg/g in controls, respectively. The adjusted odds ratios comparing each fourth quartile of mineral status versus the first quartile were as follows: selenium = 0.78 (95% CI, 0.41-1.49); zinc=0.80 (95% CI, 0.42-1.53); chromium = 0.91 (95% CI, 0.46-1.80); and mercury=0.61 (95% CI, 0.27-1.38), and all trend tests were non-significant. The nail selenium concentration in our controls reflects relatively high selenium status. No evidence of association between selenium or chromium concentrations in toenails and the risk of ESCC was detected in this population.

Dietary Flavonoid Intake Reduces the Risk of Head and Neck but Not Esophageal or Gastric Cancer in US Men and Women.

Background: Flavonoids are bioactive polyphenolic compounds found in fruits, vegetables, and beverages of plant origin. Previous studies have shown that flavonoid intake reduces the risk of certain cancers; however, few studies to date have examined associations of flavonoids with upper gastrointestinal cancers or used prospective cohorts.Objective: Our study examined the association between intake of flavonoids (anthocyanidins, flavan-3-ols, flavanones, flavones, flavonols, and isoflavones) and risk of head and neck, esophageal, and gastric cancers.Methods: The NIH-AARP Diet and Health Study is a prospective cohort study that consists of 469,008 participants. Over a mean 12-y follow-up, 2453 head and neck (including 1078 oral cavity, 424 pharyngeal, and 817 laryngeal), 1165 esophageal (890 adenocarcinoma and 275 squamous cell carcinoma), and 1297 gastric (625 cardia and 672 noncardia) cancer cases were identified. We used Cox proportional hazards regression models to estimate HRs and CIs for the associations between flavonoid intake assessed at study baseline and cancer outcomes. For 56 hypotheses examined, P-trend values were adjusted using the Benjamini-Hochberg (BH) procedure for false discovery rate control.Results: The highest quintile of total flavonoid intake was associated with a 24% lower risk of head and neck cancer (HR: 0.76; 95% CI: 0.66, 0.86; BH-adjusted 95% CI: 0.63, 0.91; P-trend = 0.02) compared with the lowest quintile. Notably, anthocyanidins were associated with a 28% lower risk of head and neck cancer (HR: 0.72; 95% CI: 0.62, 0.82; BH-adjusted 95% CI: 0.59, 0.87; P-trend = 0.0005), and flavanones were associated with a 22% lower risk of head and neck cancer (HR: 0.78; 95% CI: 0.68, 0.89; BH-adjusted 95% CI: 0.64, 0.94; P-trend: 0.02). No associations between flavonoid intake and risk of esophageal or gastric cancers were found.Conclusions: Our results indicate that flavonoid intake is associated with lower head and neck cancer risk. These associations suggest a protective effect of dietary flavonoids on head and neck cancer risk, and thus potential as a risk reduction strategy.

Low vitamin B12 increases risk of gastric cancer: A prospective study of one-carbon metabolism nutrients and risk of upper gastrointestinal tract cancer.

Previous studies have found associations between one-carbon metabolism nutrients and risk of several cancers, but little is known regarding upper gastrointestinal tract (UGI) cancer. We analyzed prediagnostic serum concentrations of several one-carbon metabolism nutrients (vitamin B12, folate, vitamin B6, riboflavin and homocysteine) in a nested case-control study within the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study of male smokers, which was undertaken in Finland between 1985 and 1988. We conducted a nested case-control study including 127 noncardia gastric adenocarcinoma (NCGA), 41 esophagogastric junctional adenocarcinoma and 60 esophageal squamous cell carcinoma incident cases identified within ATBC. Controls were matched to cases on age, date of serum collection and follow-up time. One-carbon nutrient concentrations were measured in fasting serum samples collected at baseline (up to 17 years prior to cancer diagnosis). Odds ratios and 95% confidence intervals (CI) were calculated using conditional logistic regression. Lower prediagnostic vitamin B12 concentrations at baseline were associated with a 5.8-fold increased risk of NCGA (95% CI = 2.7-12.6 for lowest compared to highest quartile, p-trend <0.001). This association remained in participants who developed cancer more than 10 years after blood collection, and after restricting the analysis to participants with clinically normal serum vitamin B12 (>300 pmol/L). In contrast, pepsinogen I, a known serologic marker of gastric atrophy, was not associated with NCGA in this population. As vitamin B12 absorption requires intact gastric mucosa to produce acid and intrinsic factor, our findings suggest vitamin B12 as a possible serologic marker for the atrophic gastritis that precedes NCGA, one more strongly associated with subsequent NCGA than pepsinogen.

Mortality from respiratory diseases associated with opium use: a population-based cohort study.

BACKGROUND: Recent studies have suggested that opium use may increase mortality from cancer and cardiovascular diseases. However, no comprehensive study of opium use and mortality from respiratory diseases has been published. We aimed to study the association between opium use and mortality from respiratory disease using prospectively collected data. METHODS: We used data from the Golestan Cohort Study, a prospective cohort study in northeastern Iran, with detailed, validated data on opium use and several other exposures. A total of 50 045 adults were enrolled from 2004 to 2008, and followed annually until June 2015, with a follow-up success rate of 99%. We used Cox proportional hazard regression models to evaluate the association between opium use and outcomes of interest. RESULTS: During the follow-up period, 331 deaths from respiratory disease were reported (85 due to respiratory malignancies and 246 due to non-malignant aetiologies). Opium use was associated with an increased risk of death from any respiratory disease (adjusted HR 95% CI 3.13 (2.42 to 4.04)). The association was dose-dependent with a HR of 3.84 (2.61 to 5.67) for the highest quintile of cumulative opium use versus never use (Ptrend<0.001). The HRs (95% CI) for the associations between opium use and malignant and non-malignant causes of respiratory mortality were 1.96 (1.18 to 3.25) and 3.71 (2.76 to 4.96), respectively. CONCLUSIONS: Long-term opium use is associated with increased mortality from both malignant and non-malignant respiratory diseases.

Prospective study of serum cysteine and cysteinylglycine and cancer of the head and neck, esophagus, and stomach in a cohort of male smokers.

BACKGROUND: The nonessential amino acid cysteine is known to be involved in many antioxidant and anticarcinogenic pathways. Cysteinylglycine is a pro-oxidant metabolite of glutathione and a precursor of cysteine. OBJECTIVE: To examine the relation between serum cysteine and cysteinylglycine and risk of gastric adenocarcinomas, esophageal squamous cell carcinomas, and head and neck squamous cell carcinomas, we conducted a nested case-control study within the Alpha-Tocopherol, Beta-Carotene Cancer Prevention study of male Finnish smokers aged 50-69 y at baseline. DESIGN: In total, 170 gastric adenocarcinomas, 68 esophageal squamous cell carcinomas, and 270 head and neck squamous cell carcinomas (identified from the Finnish Cancer Registry) were matched one-to-one with cancer-free control subjects on age and the date of serum collection. We calculated ORs and 95% CIs with the use of a multivariate-adjusted conditional logistic regression. RESULTS: Cysteine had a U-shaped association with gastric adenocarcinomas; a model that included a linear and a squared term had a significant global P-test (P = 0.036). Serum cysteinylglycine was inversely associated with adenocarcinomas of the gastric cardia (OR for above the median compared with below the median: 0.07; 95% CI: 0.01, 0.70; n = 38 cases) but not for other sites. Both cysteine and cysteinylglycine were not associated with esophageal squamous cell carcinoma or head and neck squamous cell carcinoma. CONCLUSIONS: We observed associations between serum cysteine and cysteinylglycine with upper gastrointestinal cancer risk. Future studies are needed to replicate these findings. This trial was registered at clininicaltrials.gov as NCT00342992.

Alcohol Consumption-Related Metabolites in Relation to Colorectal Cancer and Adenoma: Two Case-Control Studies Using Serum Biomarkers.

Alcohol is a known carcinogen that may be associated with colorectal cancer. However, most epidemiologic studies assess alcoholic beverage consumption using self-reported data, leading to potential exposure misclassification. Biomarkers of alcohol consumption may provide an alternative, complementary approach that reduces misclassification and incorporates individual differences in alcohol metabolism. Therefore, we evaluated the relationship between previously identified alcohol consumption-related metabolites and colorectal cancer and adenoma using serum metabolomics data from two studies. Data on colorectal cancer were obtained from a nested case-control study of 502 US adults (252 cases, 250 controls) within the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Data on colorectal adenoma were obtained from a case-control study of 197 US adults (120 cases, 77 controls) from the Navy Colon Adenoma Study. Unconditional multivariable logistic regression models were fit to calculate odds ratios (OR) and 95% confidence intervals (CI) for eight alcohol consumption-related metabolites identified in a previous analysis: ethyl glucuronide; 4-androstene-3beta,17beta-diol disulfate 1; 5-alpha-androstan-3beta,17beta-diol disulfate; 16-hydroxypalmitate; bilirubin (E,Z or Z,E); cyclo (-leu-pro); dihomo-linoleate (20:2n6); and palmitoleate (16:1n7). We found no clear association between these alcohol consumption-related metabolites and either endpoint. However, we did observe an inverse association between cyclo (-leu-pro) and colorectal adenoma that was only observed in the highest metabolite quantile (OR 4th vs. 1st Quantile = 0.30, 95% CI: 0.12-0.78; P-trend = 0.047), but no association for colorectal cancer. In conclusion, there were no adverse associations between alcohol consumption-related metabolites and colorectal cancer or adenoma.