Showing papers by "Farhad Islami published in 2013"

Prevalence, awareness and risk factors of hypertension in a large cohort of Iranian adult population.

Abstract: Background There is considerable variation in hypertension prevalence and awareness, and their correlates, across different geographic locations and ethnic groups. We performed this cross-sectional analysis on data from the Golestan Cohort Study (GCS).

Opium: An emerging risk factor for gastric adenocarcinoma

Abstract: Opium use has been associated with higher risk of cancers of the esophagus, bladder, larynx, and lung; however, no previous study has examined its association with gastric cancer. There is also little information on the associations between hookah (water pipe) smoking or the chewing of tobacco products and the risk of gastric cancer. In a case-control study in Golestan Province of Iran, we enrolled 309 cases of gastric adenocarcinoma (118 noncardia, 161 cardia, and 30 mixed-location adenocarcinomas) and 613 matched controls. Detailed information on long-term use of opium, tobacco products, and other covariates were collected using structured and validated lifestyle and food frequency questionnaires. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were obtained using conditional logistic regression models. Opium use was associated with an increased risk of gastric adenocarcinoma, with an adjusted OR (95% CI) of 3.1 (1.9 – 5.1), and this increased risk was apparent for both anatomic subsites (cardia and noncardia). There was a dose-response effect, and individuals with the highest cumulative opium use had the strongest association (OR: 4.5; 95%CI: 2.3-8.5). We did not find a statistically significant association between the use of any of the tobacco products and risk of gastric adenocarcinoma, overall or by anatomic subsite. We showed, for the first time, an association between opium use and gastric adenocarcinoma. Given that opium use is a traditional practice in many parts of the world, these results are of public health significance.

REVIEW ARTICLE A Meta-analysis of Alcohol Drinking and Oral and Pharyngeal Cancers: Results from Subgroup Analyses

Abstract: Aims: To quantify the magnitude of the association between alcohol and oral and pharyngeal cancer (OPC) by sex, smoking habits, type of alcoholic beverage and other factors. Methods: We combined findings from all case-control and cohort studies published until September 2010 and present in this article the results classified by these factors, using a meta-analytic ap- proach. Summary relative risks (RRs) were obtained using random-effects models; heterogeneity was assessed using the χ 2 test. Results: The association between alcohol and OPC risk was similar in men and women, with similar dose-response relationships. No notable differences were found with respect to geographic area and other factors, both for drinking overall and heavy (≥4 drinks/ day) drinking. Among never/non-current smokers, the pooled RRs were 1.32 (95% confidence interval, CI, 1.05-1.67) for drinking, and 2.54 (95% CI, 1.80-3.58) for heavy drinking. The corresponding RRs in smokers were 2.92 (95% CI, 2.31-3.70) and 6.32 (95% CI, 5.05-7.90). The pooled RRs for any drinking irrespective of smoking were 2.12 (95% CI, 1.37-3.29) for wine-, 2.43 (95% CI, 1.92-3.07) for beer- and 2.30 (95% CI, 1.78-2.98) for spirits-only drinking. The corresponding RRs for heavy drinking were 4.92 (95% CI, 2.80-8.65), 4.20 (95% CI, 1.43-12.38) and 5.20 (95% CI, 2.77-9.78). Conclusion: The alcohol-related RRs are similar with respect to sex, geographic area and type of alcoholic beverage. The association between alcohol and OPC is stronger in smokers than in non-smokers.

Socioeconomic status and esophageal squamous cell carcinoma risk in Kashmir, India.

Abstract: Studies have persistently associated esophageal squamous cell carcinoma (ESCC) risk with low socioeconomic status (SES), but this association is unexplored in Kashmir, an area with a high incidence of ESCC in the northernmost part of India. We carried out a case-control study to assess the association of multiple indicators of SES and ESCC risk in the Kashmir valley. A total number of 703 histologically confirmed ESCC cases and 1664 controls matched to the cases for age, sex, and district of residence were recruited from October 2008 to January 2012. Conditional logistic regression models were used to calculate unadjusted and adjusted odds ratios and 95% confidence intervals. Composite wealth scores were constructed based on the ownership of several appliances using multiple correspondence analyses. Higher education, living in a kiln brick or concrete house, use of liquefied petroleum gas and electricity for cooking, and higher wealth scores all showed an inverse association with ESCC risk. Compared to farmers, individuals who had government jobs or worked in the business sector were at lower risk of ESCC, but this association disappeared in fully adjusted models. Occupational strenuous physical activity was strongly associated with ESCC risk. In summary, we found a strong relationship of low SES and ESCC in Kashmir. The findings need to be studied further to understand the mechanisms through which such SES parameters increase ESCC risk.

Poor oral hygiene and risk of esophageal squamous cell carcinoma in Kashmir

Abstract: Several studies have suggested an association between poor oral health and esophageal squamous cell carcinoma (ESCC). We conducted a case-control study in Kashmir, a region with relatively high incidence of ESCC in north India, to investigate the association between oral hygiene and ESCC risk. We recruited 703 histologically confirmed ESCC cases, and 1664 controls individually matched to the cases for age, sex, and district of residence. Conditional logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs). We found an inverse association between teeth cleaning and ESCC risk. As compared with never cleaning teeth, the OR (95% CI) was 0.41 (0.28–0.62) for cleaning less than daily and 0.44 (0.25–0.77) for cleaning at least once a day (P for trend=0.026) in models adjusted for multiple potential confounders, including several indicators of socioeconomic status. This association persisted after we limited our analyses to never tobacco users. The inverse association between cleaning teeth and ESCC was stronger with using brushes than with using sticks/fingers. We also found an association between the number of decayed, filled, and missing teeth and ESCC risk, but the trend of the associations was not statistically significant. Avoiding solid food and cold beverages because of teeth and oral problems were also associated with ESCC risk. We found an association between poor oral hygiene indicators and ESCC risk, supporting the previous studies that showed the same associations.

A Meta-analysis of Alcohol Drinking and Oral and Pharyngeal Cancers: Results from Subgroup Analyses

Abstract: Aims: To quantify the magnitude of the association between alcohol and oral and pharyngeal cancer (OPC) by sex, smoking habits, type of alcoholic beverage and other factors. Methods: We combined findings from all case–control and cohort studies published until September 2010 and present in this article the results classified by these factors, using a meta-analytic approach. Summary relative risks (RRs) were obtained using random-effects models; heterogeneity was assessed using the χ 2 test. Results: The association between alcohol and OPC risk was similar in men and women, with similar dose–response relationships. No notable differences were found with respect to geographic area and other factors, both for drinking overall and heavy (≥4 drinks/day) drinking. Among never/non-current smokers, the pooled RRs were 1.32 (95% confidence interval, CI, 1.05–1.67) for drinking, and 2.54 (95% CI, 1.80–3.58) for heavy drinking. The corresponding RRs in smokers were 2.92 (95% CI, 2.31–3.70) and 6.32 (95% CI, 5.05–7.90). The pooled RRs for any drinking irrespective of smoking were 2.12 (95% CI, 1.37–3.29) for wine-, 2.43 (95% CI, 1.92–3.07) for beer- and 2.30 (95% CI, 1.78–2.98) for spirits-only drinking. The corresponding RRs for heavy drinking were 4.92 (95% CI, 2.80–8.65), 4.20 (95% CI, 1.43–12.38) and 5.20 (95% CI, 2.77–9.78). Conclusion: The alcohol-related RRs are similar with respect to sex, geographic area and type of alcoholic beverage. The association between alcohol and OPC is stronger in smokers than in non-smokers.

Smoking water-pipe, chewing nass and prevalence of heart disease: a cross-sectional analysis of baseline data from the Golestan Cohort Study, Iran

Abstract: Objective Water-pipe and smokeless tobacco use have been associated with several adverse health outcomes. However, little information is available on the association between water-pipe use and heart disease (HD). Therefore, we investigated the association of smoking water-pipe and chewing nass (a mixture of tobacco, lime and ash) with prevalent HD. Design Cross-sectional study. Setting Baseline data (collected in 2004–2008) from a prospective population-based study in Golestan Province, Iran. Participants 50 045 residents of Golestan (40–75 years old; 42.4% men). Main outcome measures ORs and 95% CIs from multivariate logistic regression models for the association of water-pipe and nass use with HD prevalence. Results A total of 3051 (6.1%) participants reported a history of HD, and 525 (1.1%) and 3726 (7.5%) reported ever water-pipe or nass use, respectively. Heavy water-pipe smoking was significantly associated with HD prevalence (highest level of cumulative use vs never use, OR=3.75; 95% CI 1.52 to 9.22; p for trend=0.04). This association persisted when using different cut-off points, when restricting HD to those taking nitrate compound medications, and among never cigarette smokers. There was no significant association between nass use and HD prevalence (highest category of use vs never use, OR=0.91; 95% CI 0.69 to 1.20). Conclusions Our study suggests a significant association between HD and heavy water-pipe smoking. Although the existing evidence suggesting similar biological consequences of water-pipe and cigarette smoking make this association plausible, results of our study were based on a modest number of water-pipe users and need to be replicated in further studies.

Association of tooth loss and oral hygiene with risk of gastric adenocarcinoma.

Abstract: Poor oral health and tooth loss have been proposed as possible risk factors for some chronic diseases, including gastric cancer. However, a small number of studies have tested these associations. We conducted a case-control study in Golestan Province, Iran, that enrolled 309 cases diagnosed with gastric adenocarcinoma (118 noncardia, 161 cardia, and 30 mixed-locations) and 613 sex, age, and neighborhood matched controls. Data on oral health were obtained through physical examination and questionnaire including tooth loss, the number of decayed, missing, and filled teeth, and frequency of tooth brushing. ORs and 95% confidence intervals (95% CI) were obtained using conditional logistic regression models adjusted for potential confounders. Standard one degree-of-freedom linear trend test and a multiple degree-of-freedom global test of the effect of adding oral hygiene variables to the model were also calculated. Our results showed apparent associations between tooth loss and decayed, missing, filled teeth (DMFT) score with risk of gastric cancer, overall and at each anatomic subsite. However, these associations were not monotonic and were strongly confounded by age. The results also showed that subjects who brushed their teeth less than daily were at significantly higher risk for gastric cardia adenocarcinoma ORs (95% CI) of 5.6 (1.6-19.3). We found evidence for an association between oral health and gastric cancer, but the nonmonotonic association, the relatively strong effect of confounder adjustment, and inconsistent results across studies must temper the strength of any conclusions.

Association of tooth loss and oral hygiene with risk of gastric adenocarcinoma Running title: oral health and gastric adenocarcinoma

Abstract: Word Count: 240 Cancer Research. on February 5, 2017. © 2013 American Association for cancerpreventionresearch.aacrjournals.org Downloaded from Author manuscripts have been peer reviewed and accepted for publication but have not yet been edited. Author Manuscript Published OnlineFirst on March 15, 2013; DOI: 10.1158/1940-6207.CAPR-12-0491

Disentangling the effects of race/ethnicity and socioeconomic status of neighborhood in cancer stage distribution in New York City

Abstract: Stage at diagnosis is an important prognostic factor for the majority of cancers; it may be an indicator for quality of access to health care and is usually correlated with socioeconomic status (SES) and ethnicity/race. We aimed to investigate the association between stage of cancer at diagnosis with neighborhood of residence (as proxy for SES) and ethnicity/race, while controlling for each other, in selected areas of New York City (NYC). The cancer summary data (1999–2008) were provided by the New York State Cancer Registry. Multinomial logistic regression models were applied to calculate risk estimates for being diagnosed with late- or unknown-stage (versus early-stage) cancers in two low-SES and two high-SES neighborhoods of NYC and among several ethnic/racial groups for all cancers combined and cancers of the female breast, lung, colorectum, and prostate, with additional adjustments for sex (for all cancers combined), age, and year of diagnosis. A total of 34,981 cancer cases were included in this study. There were significant and independent ethnic/racial and neighborhood disparities in stage of cancer at diagnosis of most of the cancers studied. The effect of ethnicity/race on the disparity appeared stronger than the effect of neighborhood. There was an overall decreasing trend in the proportion of late-stage cancers, particularly for colorectal cancer, and to a greater extent in the proportion of cancers without staging information. In this population, ethnicity/race seems to be a stronger predictor for late stage at diagnosis than SES, stressing the need for ethnicity/race-oriented programs for cancer screening and improved access to care.

Sample size calculation for epidemiologic studies: principles and methods.

Abstract: This paper discusses the statistical principles, methods, and software programs used to calculate sample size. In addition, it reviews the practical challenges faced in calculating sample size. We show that because of such challenges, statistical calculations often do not provide us with a clear-cut number for the study sample size; rather they suggest a range of reasonable numbers. The paper also discusses several important nonstatistical considerations in determination of sample size, such as novelty of the study and availability of resources.

Serum Ghrelin; A New Surrogate Marker of Gastric Mucosal Alterations in Upper Gastrointestinal Carcinogenesis

Abstract: Background: A few studies have indicated inverse relationships between serum ghrelin and gastric and esophageal cancers but those associations have been restricted to specific populations, including smokers and overweight individuals. We examined the association between ghrelin and gastroesophageal cancers and atrophic gastritis in a population-based setting. Methods: In total 220 gastroesophageal cancers, comprising non-cardia and cardia gastric cancer, esophageal adenocarcinoma, esophageal squamous cell carcinoma (SCC) and age and gender-matched controls were recruited. Serum ghrelin, pepsinogen I/II ratio (PGI/II) and anti-H.pylori IgG antibodies were measured. Relationships between ghrelin and gastroesophageal cancers, after adjustment for PGI/II ratio, H.pylori status and smoking, were tested using logistic regression. Furthermore, in 125 endoscopically normal volunteers, with and without histological atrophic gastritis, the relationship with ghrelin was compared. Results: Serum ghrelin (lowest vs. highest quintile) was inversely associated with gastric cancer: OR (95% CI) 8.71 (1.70– 44.59) for cardia and 6.58 (1.26–34.46) for non-cardia cancer. Lower serum ghrelin was also associated with esophageal SCC: OR (95% CI) 5.69 (1.36–23.78), but not with esophageal adenocarcinoma. A similar association was observed between gastric cancer (cardia and non-cardia) and esophageal SCC when serum ghrelin was analysed as a continuous scaled variable. In endoscopically-normal volunteers, extensive atrophic gastritis was associated with low serum ghrelin [OR (95% CI) 0.25 (0.10–0.64)]. Conclusion: Inverse associations between ghrelin and some gastroesophageal cancers suggest a potential role for serum ghrelin as a biomarker of upper gastrointestinal cancers and atrophic gastritis. In areas with a high incidence of gastric and/ or esophageal cancer, screening might be more effectively targeted to individuals with low serum ghrelin in addition to the PGI/II ratio.

A U-shaped relationship between haematocrit and mortality in a large prospective cohort study.

Abstract: Background: Only a limited number of studies have investigated the correlation between haematocrit (HCT) and mortality in the general population, and few of those studies have had data on a wide range of low and high levels of HCT. We investigated the association between baseline HCT and mortality in a prospective cohort study of 49 983 adult subjects in Iran with a broad spectrum of HCT values. Methods: Data on socio-demographic and life-style factors, past medical history, and levels of HCT were collected at enrollment. During a mean follow-up of 5 years (follow-up success rate ±99%), 2262 deaths were reported. Cox proportional hazards regression models were used to estimate hazard ratios and corresponding 95% confidence intervals. Results: There was a U-shaped relationship between categories of HCT and mortality in both sexes: both low and high levels of HCT were associated with increased overall mortality and mortality from cardiovascular disease. The U-shaped relationship persisted after several sensitivity analyses were done, including analyses restricted to non-smokers and non-users of opium; analyses excluding deaths from accidents and other external causes as well as deaths of persons with self-reported ischemic heart disease at the baseline interview for the study; and analyses excluding the first 2 years of follow-up. Self-reported past medical history and lack of data about lipids and other cellular blood components were the major limitations of the study. Conclusions: Low and high levels of HCT are associated with increased mortality in the general population. The findings in the present study can be of particular importance for low- and middle-income countries in which a substantial proportion of the population lives with suboptimal levels of HCT. © Published by Oxford University Press on behalf of the International Epidemiological Association 2013.

Variation in PAH-related DNA adduct levels among non-smokers: The role of multiple genetic polymorphisms and nucleotide excision repair phenotype

Abstract: Polycyclic aromatic hydrocarbons (PAHs) likely play a role in many cancers even in never-smokers. We tried to find a model to explain the relationship between variation in PAH-related DNA adduct levels among people with similar exposures, multiple genetic polymorphisms in genes related to metabolic and repair pathways, and nucleotide excision repair (NER) capacity. In 111 randomly selected female never-smokers from the Golestan Cohort Study in Iran, we evaluated 21 SNPs in 14 genes related to xenobiotic metabolism and 12 SNPs in eight DNA repair genes. NER capacity was evaluated by a modified comet assay, and aromatic DNA adduct levels were measured in blood by32P-postlabeling. Multivariable regression models were compared by Akaike's information criterion (AIC). Aromatic DNA adduct levels ranged between 1.7 and 18.6 per 10(8) nucleotides (mean: 5.8 ± 3.1). DNA adduct level was significantly lower in homozygotes for NAT2 slow alleles and ERCC5 non-risk-allele genotype, and was higher in the MPO homozygote risk-allele genotype. The sum of risk alleles in these genes significantly correlated with the log-adduct level (r = 0.4, p < 0.001). Compared with the environmental model, adding Phase I SNPs and NER capacity provided the best fit, and could explain 17% more of the variation in adduct levels. NER capacity was affected by polymorphisms in the MTHFR and ERCC1 genes. Female non-smokers in this population had PAH-related DNA adduct levels three to four times higher than smokers and occupationally-exposed groups in previous studies, with large inter-individual variation which could best be explained by a combination of Phase I genes and NER capacity.

Reproductive factors and risk of esophageal squamous cell carcinoma in northern Iran: a case-control study in a high-risk area and literature review.

Abstract: Several epidemiologic studies have suggested an inverse association between female reproductive factors and the risk of esophageal squamous cell carcinoma (ESCC), but the evidence is not conclusive. We examined the association of the number of pregnancies, live births, and miscarriages/stillbirths in women and the association of the number of children in both sexes with the risk of ESCC in Golestan Province, a high-risk area in Iran. Data from 297 histopathologically confirmed ESCC cases (149 women) and 568 controls (290 women) individually matched to cases for age, sex, and neighborhood of residence were included in this analysis. Conditional logistic regression was used to calculate odds ratios (ORs) and the corresponding 95% confidence intervals (CIs). The average numbers of live births and miscarriages/stillbirths among the controls were 8.2 and 0.8, respectively. Women with six or more live births were at �1/3 the risk of ESCC as those with 0-3 live births; the OR (95% CI) for having 6-7 live births was 0.33 (0.12-0.92). In contrast, the number of miscarriages/stillbirths was associated with an increase in the risk of ESCC. The OR (95% CI) for at least three versus no miscarriages/stillbirths was 4.43 (2.11-9.33). The number of children in women was suggestive of an inverse association with ESCC, but this association was not statistically significant; in men, no association was observed. The findings of this study support a protective influence of female hormonal factors on the risk of ESCC. However, further epidemiological and mechanistic studies are required to prove a protective association. © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins.

The gastro-esophageal malignancies in Northern Iran research project: impact on the health research and health care systems in Iran.

Abstract: Background: The Gastro-Esophageal Malignancies in Northern Iran (GEMINI) research project is an example of recent progress in health research in Iran. The original aim of this project was to identify etiologic factors and prevention measures for upper gastrointestinal cancers in Northern provinces of Iran, but its achievements have gone much beyond this initial goal. Methods: GEMINI consists of several projects including cancer registries, pilot studies, case-control studies, and the Golestan Cohort Study. GEMINI has been conducted through extensive collaborations between the Digestive Disease Research Center of Tehran University of Medical Sciences with other domestic and international health organizations. The achievements of GEMINI include producing new knowledge, introducing new research methods, developing and expanding health research and health care infrastructures, investing in human resources, and increasing the awareness and knowledge of policy makers and ofo cials at all levels about the importance of chronic diseases in Iran’s health priorities. Conclusions: The success of GEMINI reveals the feasibility of large-scale health research studies in developing countries and serves as a successful model not only for health research in Iran, but also for similar research studies in other developing nations.

Reply: false positive result in study on hookah smoking and cancer in Kashmir: measuring risk of poor hygiene is not the same as measuring risk of inhaling water-filtered tobacco smoke all over the world.

Abstract: Reply: False positive result in study on hookah smoking and cancer in Kashmir: measuring risk of poor hygiene is not the same as measuring risk of inhaling water-filtered tobacco smoke all over the world