Prevalence of chronic constipation and its associated factors in pars cohort study: a study of 9000 adults in Southern Iran

Background: Chronic constipation is one of the most common gastrointestinal disorders. It has negative effects on the patients' quality of life, and their productivity, and results in a high economic burden on the healthcare services. The aim of the present study was to estimate the prevalence of chronic constipation and its associated factors in pars cohort study [PCS]

Methods: A cross-sectional study was conducted on the baseline data of the PCS. Data gathering was done by structured questionnaire and physical examination. A total of 9264 subjects aged between 40 and 75 years were enrolled in the PCS. Diagnosis of chronic constipation was done using Rome IV criteria. Multivariable binary logistic regression was applied for data analysis

Results: A total of 752 [8.1%] participants were diagnosed as having chronic constipation [9.3% of female and 6.7% of male participants]. Older age [OR: 1.55, 95% CI:1.31-1.83], physical activity [OR: 0.56, 95% CI: 0.46-0.68], opium consumption [OR: 2.06, 95% CI: 1.63-2.60] , anxiety [OR: 1.38, 95% CI: 1.15-1.65], depression [OR: 1.22, 95% CI: 1.01-1.48], back pain or arthralgia [OR: 1.38, 95% CI: 1.14-1.67], insomnia [OR: 1.62, 95% CI: 1.36-1.93] and gastroesophageal reflux disease [OR: 1.51, 95% CI :1.28-1.78] were associated with the prevalence of constipation in the multivariable analysis

Conclusion: Chronic constipation was a common problem in the PCS population. Decreasing modifiable risk factors associated with constipation such as opium consumption and physical inactivity can reduce its prevalence and decrease burden of the disease.

Prevalence and correlates of gastroesophageal reflux disease in Southern Iran: pars cohort study

Background: Prevalence of gastroesophageal reflux disease [GERD] is increasing worldwide. We aimed to estimate the prevalence of GERD in Pars Cohort Study [PCS] and to find its correlates

Methods: We used the baseline data from PCS. PCS was conducted in the district of Valashahr in Fars province in southern Iran from 2012 to 2014. 9264 inhabitants who were 40-75 years old, and agreed to participate were enrolled. Data were collected by a structured questionnaire and simple physical examination of all participants

Results: Generally, 58.50% [95% CI 57.49 - 59.51] of the participants had GERD and 25.10% [95% CI 24.22 - 25.99] experienced it at least weekly. Approximately, 32.0%, 52.0%, and 24.4% of the participants reported heart burn sensation, regurgitation, and both symptoms, respectively. Being female [OR: 1.45, 95% CI 1.27 - 1.65], being older [OR: 1.20, 95% CI 1.06 - 1.36], being divorced/ widowed/separated [OR: 1.38, 95% CI 1.01 - 1.91], and lower education [OR: 1.43, 95% CI 1.02 - 2.03] were associated with frequent GERD

Conclusion: GERD is common in PCS and its prevalence is close to that in western countries. Being female, higher age, being divorced/widowed/separated, lower education, history of hypertension, anxiety, insomnia, and non-cigarette tobacco smoking were associated with frequent GERD. We are going to investigate the causal relationship between these risk factors and GERD in the next stages of PCS

[ association between dietary fat intake and pancreatic cancer risk: a large prospective study]

Pancreatic cancer [PC] is classified as one of the most deadly cancers. Since the role of diet in modifying the effects of known risk factors of PC has been well established, exploring the dietary intakes in relation to the etiology of PC can be useful for elucidating the mechanisms of the disease progression

Materials and Methods: This study was conducted within the Golestan prospective cohort study. The estimated intake of total fat and various dietary fat sources was calculated using a validated semi-quantitative food frequency questionnaire. The relationship between these dietary intakes and risk of PC was examined using Cox Regression and hazard ratio [HR] with 95% confidence interval [CI 95%] was reported

Results: During 383,630 person-years follow-up and after excluding subjects with incomplete baseline information, a total of 48,676 adults were studied. Until October 30, 2014, 54 cases of PC were confirmed by medical professionals, based on the medical records and the exact cause of death using the criteria of the International Statistical Classification of Diseases and Related Health Problems 10 [ICD10]. After adjusting for potential confounders we did not observe any statistically significant relationship between the intake of total fat and various dietary fat sources and risk of PC. There was only a significant positive association between the risk of PC and daily intake of butter, cream, and solid vegetable oil in the age-adjusted regression models [HR=2.10; 95% CI=1.04-4.21; P for trend=0.03]. However, this relationship was not remained significant anymore in the fully adjusted models

Conclusion: Based on the results of the current research, after taking into account all of the potential confounding factors, dietary intake of total fat as well as various dietary fat sources had no significant association with the risk of PC. However, it is likely that consuming substantially less saturated and trans fat sources such as dairy fats as well as solid vegetable oils may be beneficial to reduce the risk of this cancer

prevalence of non-alcoholic fatty liver disease and diabetes mellitus in an Iranian population

Background: type II diabetes mellitus [T2DM] and non-alcoholic fatty liver disease [NAFLD] are important causes of morbidity and mortality worldwide. We aimed to estimate the prevalence of DM in the context of NAFLD

Methods: in this cross-sectional study, we studied 5052 participants, aged 18 years and older, of a baseline population-based cohort in northern Iran [N=6143]. The prevalence of DM was estimated in individuals with and without NAFLD. The association between NAFLD and T2DM was evaluated using logistic regression with the adjustment of confounding effects of age, sex, body mass index, lipid profiles, and fasting insulin

Results: in men, the prevalence [95% confidence interval] of T2DM was 5.34% [4.35%-6.34%] and 15.06% [13.12%-17.00%] in individuals without and with NAFLD, respectively [p <0.001]. In women without NAFLD, the prevalence was 8.27% [6.83%-9.71%] while in the presence of NAFLD, the prevalence was 27.21% [24.59%-29.83%], [p <0.001]. In univariate analysis, the chance of having T2DM was 3.700 [3.130-4.380] times more in patients with NAFLD compared with subjects without NAFLD [p<0.001]. This chance was reduced [Odds Ratio=1.976, 95% CI: 1.593-2.451, p <0.001] after removing the effects of other variables

Conclusion: the prevalence of T2DM is increased in the context of NAFLD. This condition may be considered as an independent predictor of T2DM

[Higher intake of dietary fiber, but not fruits or vegetables is associated with lower risk of pancreatic cancer: a large prospective study]

Background: pancreatic cancer [PC] is classed as the 7th leading cause of cancer-related death in the world. Previous evidence indicates that hyperglycemia, insulin resistance, diabetes, and obesity are implicated in pancreatic carcinogenesis. Thus, evaluation of the dietary intakes in the etiology of PC can be useful to identify the risk factors of the disease

Materials and Methods: we examined the association between total intake of fruits, vegetables, and dietary fiber and the risk of PC in 50,045 participants aged 40-75 years within the Golestan Cohort Study. Dietary data were collected using a validated semi-quantitative food-frequency questionnaire, which was administered at baseline. Cox proportional hazards models were used to estimate multivariate hazard ratio with 95% confidence interval

Results: during 383,630 person-years of follow-up and after excluding the participants with incomplete baseline information, a total of 48,676 adults were evaluated. Until October 30, 2014, 54 cases of PC were confirmed based on the exact cause of death using ICD10 criteria. After considering all potential confounding factors, there was only a statistically significant inverse association between the risk of PC for the highest tertile of daily fiber intake compared with the lowest tertile [HR=0.41; 95% CI= 0.15-1.05; P for trend= 0.05]. However, the relationship between fruits and vegetables and PC risk was not statistically significant

Conclusion: in summary, based on the findings of this study, increased dietary fiber may reduce the risk of PC. This result highlights the importance of a diet rich in fiber in order to prevent PC progression. Finally, given the limited number of studies in this field and inconclusive results, there is still a need for new prospective studies with long follow-up

Epidemiological profile of hepatitis B virus infection in Iran in the past 25 years; a systematic review and meta-analysis of general population studies

Background: Chronic hepatitis B virus [HBV] infection is one of the most important health problems worldwide with a high rate of morbidity and mortality. It is a major risk factor for cirrhosis and liver cancer. Currently, Iran is located in the intermediate HBV zone; however, recent studies have provided some evidence indicating an epidemiological change in the country. The aim of this study was to estimate the prevalence of HBV in Iran

Methods: A systematic review was conducted to evaluate the studies performed in the past 25 years that have reported the prevalence of HBV infection and its associated factors in the Iranian general population [1990-2014]. Any study assessing and reporting serum Hbs Ag levels was included in this review

Results: After excluding all impertinent studies, 19 eligible studies were included in the analysis. The overall prevalence of HBV was 3% [95% CI 2% to 3%]. Its distribution showed that the prevalence of HBV varies in different provinces from 0.87% to 8.86%. The HBV rate was highest in the Golestan [8.86%] and lowest in the Kurdistan [0.87%] provinces

Conclusion: This study provides some evidence about the prevalence of HBV in Iran. However, the collected data was very heterogenic, even within a single province, which made it hard to estimate a single-point prevalence. High quality studies are needed to find reliable information about HBV prevalence and to decrease the heterogeneity of results in the country

nail as a biomonitor of trace element status in Golestan cohort study

Background: In the Golestan Cohort Study that was launched to investigate the causes of esophageal cancer, a complete biospecimen bank was established for storage of collected blood, urine, hair, and nail samples. The objective of this study was to evaluate the feasibility of nail samples as a biomarker of selected trace elements status

Methods: Thirty toenail samples were selected randomly from the participants of Golestan Cohort Study [GCS]. The samples were cleaned and analyzed for selenium, mercury, chromium, iron, zinc, and scandium by instrumental neutron activation analysis at the University of Missouri Research Reactor Center. Pearson correlation coefficients were computed for selected trace elements concentration versus scandium concentration to assess terrestrial contamination

Results: The selenium, zinc, and mercury were not correlated with scandium, suggesting they were free from substantial contamination. The high correlations of scandium with iron and chromium suggest that the iron and chromium levels may be compromised by terrestrial contamination. The coefficients of variation for duplicate samples for selenium and zinc were 2.6% and 7.2%, respectively

Conclusion: The nail samples from Golestan Cohort Study appears to be useable as a biomarker of selenium, zinc, and mercury and could be considered for use in future studies

Manganese intake and risk of esophageal cancer in golestan cohort study

Background: Infections attributed to Helicobacter pylori [H. pylori] involve almost half of the world's population. One of the effects is auto-antibody induction and cross-reaction with numerous proteins in the body. As a result of its widespread prevalence and importance, this study evaluates the associations between H. pylori and thyroid auto-antibodies

Materials and Methods: This study enrolled 100 patients who were candidates for gastroesophageal endoscopy that referred to the Yazd Gastrointestinal Clinic. Patients underwent the following laboratory analyses: urease test, anti-H. pylori [IgG], TSH, T4, T3 and thyroid auto-antibodies [anti-thyroglobulin, anti-thyroid peroxides] Patients were divided into two groups of H. pylori positive and negative according to the results of the anti-H. pylori IgG and urease tests. The level of thyroid auto-antibodies and thyroid function tests were compared between groups. Data were analyzed with chi-square and t-tests. SPSS software version 17 was used for data analysis

Results: Overall, 61 % of patients were H. pylori positive. The mean anti-Thyroid peroxidase level in the H. pylori positive group was significantly more than the negative group [p<0.01]. In addition, 19.7% of H, pylori positive patients and 5.1% of H. pylori negative patients had positive anti-TPO levels, which the difference between both groups was significant [p<0.04]. There was no significant difference in thyroid fimction between the two groups

Conclusion: Although no significant difference in thyroid function was seen in the two groups more patients tested positive for anti-TPO levels in the H. pylori positive group, which was suggestive of thyroid auto-antibody induction by H. pylori

Inverse association of plasma level of glutathione peroxidase with liver fibrosis in chronic hepatitis B: potential role of iron

Background: Oxidative stress plays a major pathogenic role in liver injury following chronic hepatitis B. Glutathione peroxidase [Gpx] has a central role in regulating the oxidative state. Hepatitis B virus [HBV] results in down-regulation of Gpx. On the other hand, iron homeostasis is disrupted in HBV infected patients. Therefore, the objective of this study was to assess the interplay of Gpx and serum iron on clinical and virological characteristics of patients with chronic HBV infection

Method: One hundred and fifty adult, treatment-naïve, patients with chronic hepatitis B were randomly selected from an ongoing cohort of patients with HBV. Plasma Gpx1 concentration and HBV DNA quantity were measured. Liver stiffness was measured by transient elastography

Results: Serum iron had a positive association with HBV DNA count in the total population. Serum iron was not associated with liver stiffness. However, HBV DNA was significantly associated with liver stiffness only in male patients. Serum Gpx was inversely associated with liver stiffness. Serum iron and Gpx had indirect effects on liver stiffness via HBV DNA count. We observed distinct effects of serum iron on HBV DNA and Gpx on liver stiffness in male and female patients

Conclusion: We identified interplay of serum iron and Gpx1 in relation to level of liver fibrosis in patients with chronic hepatitis B. Our results suggest that oxidative stress and serum iron are differentially implicated in the progression of chronic hepatitis B in male and female patients

association between dietary carbohydrate intake and pancreatic cancer risk: a large prospective study

Background: Pancreatic cancer [PC] is ranked as the 7th leading cause of cancer death worldwide and is one of the most deadly cancers. Several lines of evidence indicate that insulin resistance, diabetes, and obesity are implicated in its carcinogenesis

Materials and Methods: We examined the association between the consumption of carbohydrate foods and risk of PC in 50,045 participants [21241 men and 28804 women aged 40 to 75 years] of the Golestan Cohort Study in northeastern Iran. Dietary data were collected using a validated semi-quantitative food-frequency questionnaire. Cox proportional hazards models were used to estimate multivariate hazard ratio with 95% confidence interval

Results: During 8.5 years [383,630 person-years] of follow-up and after excluding participants with incomplete data, a total of 48,676 adults [20,683 men and 27,993 women] were studied. Until October 30, 2014, 54 cases of pancreatic cancer were confirmed by a medical team, based on the medical records and the exact cause of death according to ICD10 criteria. After adjusting for age, total energy intake, history of diabetes, smoking status, education, opium consumption, body mass index, waist to hip ratio, ethnicity, sex, the metabolic equivalent of task [MET], residential area, and socioeconomic status, we did not observe any statistically significant relationship between consumption of total carbohydrate and carbohydrate foods including whole grains, refined grains, sugars, and potatoes and risk of PC

Conclusion: Based on the results of the present study, dietary intake of total carbohydrate as well as various carbohydrate food sources had no significant association with the risk of PC. Finally, given the limited number of studies in this field and their inconclusive results, there is still a need for new prospective studies with long follow-up

Trend of gastrointestinal and liver diseases in iran: results of the global burden of disease study, 2010

The general pattern of epidemiologic transition from communicable to non-communicable diseases is also observed for gastrointestinal and liver diseases [GILD], which constitute a heterogeneous array of causes of death and disability. We aimed to describe the trend of GILD in Iran based on the global burden of disease [GBD2010] study from 1990 to 2010. The trend of number of deaths, disability, adjusted life years [DALYs] and their age-standardized rates caused by 5 major GILD have been reported. The change in the rankings of major causes of death and DALY has been described as well. The age standardized rates of death and DALYs in both sexes have decreased from 1990 to 2010 for most GILD. The most prominent decreases in death rates are observed for diarrheal diseases, gastritis and duodenitis, and peptic ulcer disease. Positive trends are observed for liver cancer, pancreatic cancer, and gall bladder cancer. Diarrheal diseases have retained their 1[st] rank among children under 5. Among adults, decreased ranks are observed for diarrheal diseases, appendicitis, gastritis and duodenitis, gall bladder diseases, pancreatitis, and all types of cirrhosis. The trends in age standardized rates of DALYs, deaths, and YLLs are negative for almost all GILD, and especially for diarrheal diseases. However, there is no upward or downward trend in rates of years lost due to disability [YLDs] for most diseases. Total numbers of DALYs and deaths due to acute hepatitis C, stomach cancer, and liver cancers are rising. The total DALYs due to overall digestive diseases except cirrhosis and DALYs due to cirrhosis are both somehow stable. No data has been reported for GILD that are mainly diagnosed in outpatient settings, including gastroesophageal reflux disease, irritable bowel syndrome, and non-alcoholic fatty liver disease. The results of GBD 2010 demonstrate that the rates of most GILD are decreasing in Iran but total DALYs are somehow stable. However, as diseases detected in outpatient settings have not been captured, the burden of GILD seems to be underestimated. Population-based studies at national level are required for accurate reports

Burden of gastrointestinal and liver diseases in iran: estimates based on the global burden of disease, injuries, and risk factors study, 2010

Gastrointestinal and liver diseases [GILD] constitute a noteworthy portion of causes of death and disability in Iran. However, data on their prevalence and burden is sparse in Iran. The Global Burden of Disease [GBD] study in 2010 has provided invaluable comprehensive data on the burden of GILD in Iran. Estimations of death, years of life lost due to premature death [YLL], years of life lost due to disability [YLD], disability-adjusted life years [DALY], life expectancy, and healthy life expectancy have been reported for 291 diseases, 67 risk factors, 1160 sequelae, for both sexes and 19 age groups, form 1990 to 2010 for 187 countries. In the current paper, 5 major categories of gastrointestinal [GI] and liver diseases have been investigated as follows: GI infectious diseases, GI and liver cancers, liver infections, chronic end stage liver disease, and other digestive diseases. Among women, 7.6% of all deaths and 3.9% of all DALYs were due to digestive and liver diseases in 2010. The respective figures in men were 7.8% of deaths and 4.6% of DALYs. The most important cause of death among children under 5 is diarrhea. Among adults between 15 to 49 years old, the main causes of death are GI and liver cancers and cirrhosis, while diarrhea still remains a major cause of DALY. Among adults 50 years and above, GI and liver cancers and cirrhosis are the main causes of both deaths and DALYs. Gastritis and duodenitis, diarrheal diseases, gall bladder and bile duct diseases, acute hepatitis A, peptic ulcer disease, appendicitis, and acute hepatitis A mainly cause disability rather than death. GBD study provides invaluable source of data on burden of GILD in Iran. However, there exist limitations, namely overestimation of burden of liver cancer and underestimation of the burden of GI diseases that are usually diagnosed in outpatient settings. The collaboration of scientists across the world and specifically those from developing countries is necessary for improving the accuracy of future updates of GBD in these countries

Soy isoflavones supplementation for patients with irritable bowel syndrome: a randomized double blind clinical trial

Irritable bowel syndrome [IBS] is one of the common gastrointestinal disorders with unknown etiology. In experimental models, it is proposed that soy isoflavones may suppress the clinical and psychological symptoms of IBS by alteration of gut barrier tight junctions. We conducted this study to evaluate the effects of soy isoflavones on IBS symptoms and patients' quality of life. In a randomized double blind placebo-controlled clinical trial, 67 patients with IBS were allocated to consume either soy isoflavones capsules or a placebo for 6 weeks. The primary outcome was a significant reduction in symptoms severity score and the secondary outcome was a significant improvement in quality of life. 45 participants completed the study. There was no significant changes in mean differences of symptoms severity score between the two groups; however soy isoflavone supplementation could significantly improve the quality of life scores [p=0.009]. Soy isoflavones supplementation could improve the quality of life in patients with IBS; however it did not suppress the symptoms seventy in 6 weeks. Further research with a longer duration is needed to determine the sustained clinical efficacy. This study was registered at clinicaltrials.gov as NCT02026518

Immune-regulatory events in the clearance of HBsAg in chronic hepatitis B: focuses on HLA-DP

Successful clearance of hepatitis B virus [HBV] is a promising event in which host's immune system will attempt to get rid of the virus. The immunological events of HBsAg seroclearance have attracted great attention in both natural history investigations and therapeutic trials. Recent genome-wide association studies [GWAS] has confirmed polymorphisms in the human leukocyte antigen [HLA]-DP locus associated with spontaneous HBV clearance. In this review the impact of host immune response in declining HB5Ag during the natural history of the infection has been discussed

Downregulation of plasma MiR-142-3p and MiR-26a-5p in patients with colorectal carcinoma

Colorectal cancer is one of the most commonly diagnosed cancers and cancer- related death worldwide. Identification of new specific biomarkers could be helpful to detection of this malignancy. Altered plasma microRNA expression has been identified in many cancers, including colorectal cancer. The main objective of this study was to identify the circulating microRNAs with the most expression changes in colorectal cancer patients compared with neoplasm free healthy individuals. MicroRNA expression profiling was performed on plasma samples of 37 colorectal cancer patients and 8 normal subjects using microRNA microarray. Quantitative real-time reverse transcription polymerase chain reaction was used to validate the two selected altered microR NAs. Plasma samples from 61 colorectal cancer patients and 24 normal subjects were used in our validation study. In profiling study we found a panel of six plasma microRNAs with significant downregulation. MicroRNA-142-3p and microRNA-26a-5p were selected and validated by polymerase chain reaction. Our results demonstrated that expression levels of plasma microRNA-142-3p and microRNA-26a-5p were significantly downregulated in patients with colorectal cancer when compared to control group. Our findings suggest that downregulation of plasma microRNA-142-3p and microRNA-26a-5p might serve as novel noninvasive biomarkers in the diagnosis of colorectal cancer, although more studies are needed to highlight the theoretical strengths

Burden of gastrointestinal and liver diseases in middle east and north africa: results of global burden of diseases study from 1990 to 2010

Gastrointestinal and liver diseases [GILDs] are major causes of death and disability in Middle East and North Africa [MENA]. However, they have different patterns in countries with various geographical, cultural, and socio-economic status. We aimed to compare the burden of GILDs in Iran with its neighboring countries using the results of the Global Burden of Disease [GBD] Study in 2010. Classic metrics of GBD have been used including: age-standardized rates [ASRs] of death, years of life lost due to premature death [YLL], years of life lost due to disability [YLD], and disability adjusted life years [DALY]. All countries neighboring Iran have been selected. In addition, all other countries classified in the MENA region were included. Five major groups of gastrointestinal and hepatic diseases were studied including: infections of gastrointestinal tract, gastrointestinal and pancreatobilliary cancers, acute hepatitis, cirrhosis, and other digestive diseases. The overall burden of GILDs is highest in Afghanistan, Pakistan, and Egypt. Diarrheal diseases have been replaced by gastrointestinal cancers and cirrhosis in most countries in the region. However, in a number of countries including Afghanistan, Pakistan, Turkmenistan, Egypt, and Yemen, communicable GILDs are still among top causes of mortality and morbidity in addition to non-communicable GILDs and cancers. These countries are experiencing the double burden. In Iran, burden caused by cancers of stomach and esophagus are considerably higher than other countries. There is an overall overestima-tion of liver cancer and underestimation of other gastrointestinal and pancreatobilliary cancers. The diseases that are mainly diagnosed in outpatient settings have not been captured by GBD

Repository of human blood derivative biospecimens in biobank: technical implications

Human biorepositories are collection of biological samples and health information from a large number of participants generally in the cohort studies. The main purpose of established biobanks is organization of biomedical research for upgrading the knowledge of human disorders from cancer to infectious and rare disease. The studies of generation relationships and understanding the preclinical stages of ageing are also from the solution of bitobank. This review overview the significance and storage condition of biospecimens including whole blood, red blood cells [RBC], buffy coat, plasma, serum, DNA and RNA that derived from blood in human biobanks. These biological samples provide valuable information on the prevalence of germline mutations, epigenetic modifications or interaction between genes and proteins in associated with the development of certain types of disease. The quality of biospecimen in biobanks is a powerful tool for valid identification of biomarkers. Therefore optimum qualities of human biological samples in long time storage that have been assessed in several studies also indicate in this review

Adult hepatic progenitor cell niche: how it affects the progenitor cell fate

The hepatic progenitor cell [HPC] niche is a special microenvironment composed of different cell types, extracellular matrix [ECM] components, growth factors and cytokines released by the niche cells that help to maintain the characteristics of HPCs and the balance between their activation, proliferation and differentiation

Composition of this special microenvironment, created in response to specific liver damage, together with critical interactions between different partners of the HPC niche can determine the fate decision and differentiation pathways of HPCs

A number of recent studies have shed light on factors and signals from the HPC niche that determines the choice of HPCs differentiation towards a specific cell type depending on the nature of the liver injury and resultant microenvironment created by this injury

This paper seeks to provide an in-depth review, through a literature review and the authors' experiences, of the most recent findings on the role of the HPC niche in fate choice option of HPCs toward either hepatocytes or bile duct epithelial cells and its clinical relevance

Systematic review of zinc biomarkers and esophageal cancer risk

It is hypothesized that poor zinc nutritional status is associated with an increased risk of esophageal cancer [EC], but current evidence is contradictory. Since some factors may influence zinc absorption, its status may be better evaluated thorough biomarkers. The objectives of this study were to perform a systematic review on the association of zinc biomarkers with EC in observational studies and to evaluate the efficacy of zinc supplements in preventing EC in randomized trials. The MEDLINE database was searched in December 2013 for studies written in English with relevant keywords. Articles which met inclusion criteria were included in this study. Eleven observational studies that measured zinc biomarkers and eight randomized trials which evaluated supplements containing zinc, met our inclusion criteria. The majority of studies suggested that higher zinc status was inversely associated with EC risk. Most of the evidence for this hypothesis comes from case-control studies, which may introduce bias. Cohort studies are needed to establish whether poor zinc status is associated with increased risk for EC. Findings from trials are inconclusive as there is no data from single agent trials. However, the evidence is not still strong enough to conclude a protective role of zinc in EC

Cohort profile: Golestan hepatitis B cohort study-a prospective long term study in northern Iran

Hepatitis B virus [HBV] infection is the most common cause of end stage liver disease in Iran and in Golestan province. Large-scale population-based prospective cohort studies with long term follow-up are the method of choice to accurately understand the natural course of HBV infection. To date, several studies of HBV epidemiology, natural history, progression to cirrhosis and association with HCC have been reported from other countries. However, few of these are prospective and fewer still are population-based. Moreover, the underlying molecular mechanisms and immunogenetic determinants of the outcome of HBV infection especially in low and middle income countries remains largely unknown. Therefore, the hepatitis B cohort study [HBCS], nested as part of the Golestan Cohort Study [GCS], Golestan, Iran was established in 2008 with the objective to prospectively investigate the natural course of chronic hepatitis B with reference to its epidemiology, viral/host genetic interactions, clinical features and outcome in the Middle East where genotype D HBV accounts for >90% of infections. In 2008, a baseline measurement of HBV surface antigen [HBsAg] was performed on stored serum samples of all GCS participants. A sub-cohort of 3,505 individuals were found to be HBsAg positive and were enrolled in the Golestan HBCS. In 2011, all first degree relatives of HBsAg positive subjects including their children and spouses were invited for HBV serology screening and those who were positive for HBsAg were also included in the Golestan HBCS