Applications of advanced materials in bio-sensing in live cells: Methods and applications.

A wide variety of species, such as different ions, reactive oxygen species, and biomolecules play critical roles in many cell functions. These species are responsible for a range of cellular functions such as signaling, and disturbed levels could be involved in many diseases, such as diabetes, cancer, neurodegeneration etc. Thus, sensitive and specific detection methods for these biomarkers could be helpful for early disease detection and mechanistic investigations. New ultrasensitive sensors for detection of markers within living cells are a growing field of research. The present review provides updates in live cell-based biosensing, which have been published within the last decade. These sensors are mainly based on carbon, gold and other metals, and their physicochemical advantages and limitations are discussed. Advanced materials can be incorporated into probes for the detection of various analytes in living cells. The sensitivity is strongly influenced by the intrinsic properties of the nanomaterials as well their shape and size. The mechanisms of action and future challenges in the developments of new methods for live cell based biosensing are discussed.

Comparison of genome-wide analysis techniques to DNA methylation analysis in human cancer.

DNA methylation was the first epigenetic modification to be detected in human cancers with specific relation to aberrant gene expression. Herein, DNA methylation analysis explains how epigenetic patterns affect gene expression level. Hypermethylation at tumor suppressor gene loci leads to increased tumorigenesis due to tumor suppressor gene silencing, whereas global hypomethylation of CpG islands (CGIs) is followed by genomic instability and aberrant activation of multiple oncogenes. Therefore, characterization of the genes which silenced or activated epigenetically in human tumor cells can improve our understanding of cancer biology. Different genome-wide methodologies are applied to evaluate methylation status. Various commonly conducted techniques for this evaluation are reviewed in this paper. We provided comparative description of the procedures, advantages, and drawbacks of genome-wide DNA methylation analysis methods and biological applications, to give information on selecting the appropriate method for different methylation studies.

Influance of regular swimming on serum levels of CRP, IL-6, TNF-α in high-fat diet-induced type 2 diabetic rats.

Due to key role of inflammation in pathogenesis of type 2 diabetes mellitus (T2DM), aim of this study was evaluating the influance of regular swimming on serum levels of C-reactive protein (CRP), interlukin-6 (IL-6), tumor necrosis factor-α (TNF-α) in high-fat diet-induced diabetic rats. Fourty male Wistar rats were randomly divided into control, diabetic, exercise and diabetic-exercise groups (n = 10). Diabetes was induced by high-fat diet and streptozotocin (35 mg/kg, i.p.). In exercise groups, after induction of diabetes, animals were subjected to swimming (60 min/5 days a week) for 10 weeks. At the end of training, rats were anestatized and blood samples and pancreatic tissues were collected and used for evaluation of CRP, IL-6, TNF-α and pancreatic histopatholology. Our results showed significantly increase in lymphocytes, monocytes and decrease in neutrophils in diabetic rats (p < 0.01), which these parameters significantly reversed to control levels by induction of swimming (p < 0.01). In diabetic group, the levels of CRP, IL-6 and TNF-α increased (p < 0.01), and swimming decreased these factors significantly. Histopathological results of this study also showed that swimming can prevent damage induced by diabetes. The present study indicates that swim training is associated with improved inflammation and inflammatory mediators and pancreatic damage.

Emerging Epidemic of Inflammatory Bowel Disease in a Middle Income Country: A Nation-wide Study from Iran.

BACKGROUND: The burden of inflammatory bowel disease (IBD) hasn't been reported in Iran. We aimed to estimate the prevalence and incidence of IBD and its trend in Iran at national and subnational level from 1990 to 2012. METHODS: We conducted a systematic review of English and Persian databases about the epidemiology of IBD. We also collected outpatient data from 17 provinces of Iran using almost all public and private referral gastroenterology clinics. Prevalence and incidence rate was calculated at national and subnational levels. The Kriging method was used to extrapolate provinces with missing data and GPR model to calculate time trends of rates at subnational level. RESULTS: We found 16 case series, two population-based studies, and two review articles. We collected 11,000 IBD cases from outpatient databases. Among them, 9,269 (84.26%) had ulcerative colitis (UC), 1,646 (14.96%) had Crohn's disease (CD), and 85 had intermediate colitis (IC). A total of 5,452 (49.56%) patients were male. Mean age at diagnosis was 32.80 years (CI: 13 - 61) for UC and 29.98 years (CI: 11 - 58) for CD. Annual incidences of IBD, UC, and CD in 2012 were 3.11, 2.70, and 0.41 per 100,000 subjects respectively. Prevalence of IBD, UC, and CD in 2012 were 40.67, 35.52, and 5.03 per 100,000 subjects respectively. The incidence of UC and CD showed a significant increase during the study period (P for trend < 0.05). CONCLUSIONS: The incidence and prevalence of IBD are increasing in Iran. Establishing a national IBD registry seems necessary for comprehensive care of IBD patients in Iran.

Immunology and vaccines and nanovaccines for Helicobacter pylori infection.

Helicobacter pylori infection is very common worldwide and is an important cause of gastritis, peptic ulcer disease, gastric mucosa-associated lymphoid tissue lymphoma, and gastric adenocarcinoma. Since the eradication requires treatment with multidrug regimens, prevention of primary infection by a suitable vaccine is attractive. Developing vaccines on the spot when and where an infection is breaking out might be possible, thanks to engineered nanoparticles. In this review, the nature of the host immune response to H. pylori infection is considered. We explain recent candidate vaccines and prophylactic or therapeutic immunization strategies for use against H. pylori. We also describe identification of different types of immune responses that may be related to protection against H. pylori infection. Thus, it seems that there is still a strong need to clarify the main protective immune response against H. pylori.

Association of plasminogen activator inhibitor-1 gene polymorphism with inflammatory bowel disease in Iranian Azeri Turkish patients.

BACKGROUND/AIM: Previous studies have shown the association of some genetic factors, such as Plasminogen activator inhibitor type-1 (PAI-1) 4G/5G polymorphism, with the development of inflammatory bowel disease (IBD). We aimed to study this polymorphism as a risk factor in IBD patients in this cohort. PATIENTS AND METHODS: One hundred and fifteen IBD patients and 95 healthy controls were selected from Iranian Azeri Turks and -6754G/5G polymorphism of PAI-1 gene was tested by polymerase chain reaction using allele-specific primers confirmed by sequencing. RESULTS: There was no significant difference of PAI-1 polymorphism between IBD patients and the control group (P>0.05). Furthermore, these data showed no significant difference between Crohn's disease and ulcerative colitis patients. However, 4G/4G homozygotes have reduced probability to progression of loss of appetite, whereas 5G/5G genotypes have increased risk for development of chronic diarrhea without blood, nausea, and loss of appetite. CONCLUSIONS: Although our study showed no significant association of PAI-1 polymorphism between patients and control group, the carriers of 4G/4G genotype and 4G allele had reduced risk for the progression of IBD features in this cohort.

The therapeutic effect of adding emotional awareness training to standard medical treatment for irritable bowel syndrome: a randomized clinical trial.

OBJECTIVE: This randomized trial evaluated the therapeutic effect of emotional awareness training on the severity and frequency of pain in patients with irritable bowel syndrome (IBS). Patients' level of alexithymia was also measured. METHOD: The study involved 100 patients diagnosed with IBS according to the Rome-III criteria. Patients' mean age was 34.98 years (standard deviation 10.22 years) and 60% of the patients were female. Seventy eligible patients were assigned randomly to one of two treatment groups. One group received standard symptom-oriented medical treatment only (MT group), while the second group, termed the emotional awareness group (EMT), was educated to increase conscious awareness of eight primary emotions in addition to receiving standard symptom-oriented medical treatment. This study was conducted over 20 months. All patients received 5 weeks of symptom-oriented medical treatment; patients in the EMT group also had two emotion awareness training sessions and recorded their emotions in a daily diary. Sixty patients completed the study. RESULTS: Patients with IBS scored significantly higher on all aspects of alexithymia compared with healthy controls. The severity of pain decreased significantly in both groups, with a larger percentage of the patients in the EMT group who completed the study having a significant decrease in pain (54% in the EMT group vs. 36% in the MT group); this finding was replicated in an intent-to-treat analysis. The same results were observed for frequency of pain in patients who completed the study (59% in the EMT group vs 43.4% in the MT group), but this finding was not replicated in an intent-to-treat analysis. These patterns were not influenced by level of alexithymia, age, or gender. CONCLUSION: Adding emotional awareness training to medical treatment resulted in a better therapeutic response in abdominal pain in patients with IBS.

Effect of the C3435T polymorphism of the multidrug resistance 1 gene on the severity of inflammatory bowel disease in Iranian Azeri Turks.

BACKGROUND/AIM: Multidrug resistance 1 (MDR1) gene encodes for P-glycoprotein (P-gp), a transmembrane efflux pump transferring both exogenous and endogenous substrate from the cells. In the human gastrointestinal tract, P-gp is found in high concentrations on the epithelial cells of the colon and small intestine. It is hypothesized that the expression level of MDR1 gene is related to susceptibility of both forms of inflammatory bowel disease (IBD). The aim of this study was to investigate the association of C3435T Single Nucleotide Polymorphism in IBD patients with/without clinical symptoms in Iranian Azeri Turks. SETTINGS AND DESIGN: A total of 116 patients with IBD and 92 healthy subjects were analyzed. MATERIALS AND METHODS: We investigated the distribution of MDR1 C3435T polymorphism via polymerase chain reaction - Restriction Fragment Length Polymorphism technique. STATISTICAL ANALYSIS USED: All statistical analyses were calculated with the SPSS for Windows 16.0. The Fisher exact test was used to test for departure from Hardy-Weinberg equilibrium of the genotype frequencies ( P > 0.05). RESULTS: The data showed that IBD patient with homozygous variant carrying MDR1 3435 T/T genotype has elevated risk for development of routine IBD clinical symptoms like Abdominal pain ( P = 0.005) and chronic Diarrhea ( P = 0.013) compared with MDR1 3435 C/C homozygotes who has reduced risk for development of IBD symptoms. CONCLUSIONS: Our data showed that patients with MDR1 3435 T/T are more susceptible to the development of some routine IBD clinical symptoms ( P < 0.05). This study suggests a protective role for the MDR1 3435 C/C versus MDR1 3435 T/Tgenotype and C versus T allele for the progression of IBD in this cohort.

Bone density and bone metabolism in patients with inflammatory bowel disease.

BACKGROUND/AIMS: Patients with inflammatory bowel disease (IBD) are at high risk for low bone mineral density (BMD). This study aimed to evaluate BMD in IBD patients and its relationship with bone metabolism in a group of Iranian patients. PATIENTS AND METHODS: A cross-sectional study was conducted on patients with IBD to assess BMD status and serum biochemical factors. After getting the demographic data from 200 patients, they were screened using dual-energy X-ray absorptiometry of the lumbar spine (L2-L4) and femoral neck for BMD status. Serum levels of calcium, phosphate, alkaline phosphatase (ALP), and 25-hydroxyvitamin D (25-OH vitamin D) were measured to assess the bone metabolism status. RESULTS: Two hundred patients with IBD were enrolled in the study. One hundred and eighty three (91.5%) patients were identified as having ulcerative colitis (UC) and 17 (8.5%) as having Crohn's disease (CD). Based on the lumbar and femoral neck bone mass densitometry, 148 (74.4%) patients had low BMD at either lumbar spine or femoral neck. Of these, 100 patients (50.3%) were osteopenic and 48 patients (24.1%) were osteoporotic. A 58.6% and 61% of patients with UC had low BMD in the lumbar and femoral neck, respectively. These results for those with CD were 76.5% and 70.6%, respectively. The mean of femoral neck and lumbar T-scores in patients with UC were -1.14 and -1.38, and in patients with CD were -1.24 and -1.47, respectively (P > 0.05). The mean (±SD) levels for calcium (Ca) in UC and CD were in the normal range. The mean (±SD) levels of ALP and 25-OH vitamin D in both the groups were in the normal range, and in comparison between groups (UC and CD), no significant differences were observed (P = 0.20 for ALP and P = 0.44 for 25-OH vitamin D). In the assessment of correlation between biochemical markers and BMD, an inverse correlation between lumbar T-score and ALP or 25-OH vitamin D only in patients with UC was observed. CONCLUSIONS: The high prevalence of low BMD in the Iranian population with IBD needs attention. The subclinical vitamin D deficiency may contribute to bone loss in IBD patients, which is more pronounced in patients with UC in this study because of the small population of patients with CD.

The status of antimicrobial resistance of Helicobacter pylori in Eastern Azerbaijan, Iran: comparative study according to demographics.

Helicobacter pylori-associated infections are extremely common in Iran, but few data about antibiotic sensitivity of H. pylori are available for this region. The purpose of this study was to investigate the prevalence of resistance in isolates against commonly used antibiotics in Eastern Azerbaijan, Iran, and the dependence of prevalence on the sex and age of patients. H. pylori isolates were collected by culture from gastric biopsies. Antibiotic susceptibility of isolates was determined by use of the disk agar diffusion test, and the minimum inhibitory concentration of clarithromycin was established by use of the Etest. A total 395 of biopsy specimens were studied; 112 samples of H. pylori were isolated (28.3 %), 55 (49 %) from males and 57 (51 %) from females. The prevalence of resistance to clarithromycin, metronidazole, erythromycin, amoxicillin, ciprofloxacin, rifampin, nitrofurantoin, and tetracycline were 16 (14.3 %), 86 (76.8 %), 29 (26.0 %), 32 (28.6 %), 37 (33.0 %), 32 (28.6 %), 13 (11.6 %), and 21 (18.7 %), respectively. Antimicrobial resistance was not statistically significantly associated with sex or age. Furthermore, the prevalence of resistance to metronidazole was high and that to clarithromycin was reasonable, consistent with reported low success in H. pylori treatment in this area. Therefore, continuous surveillance of antibiotic resistance of H. pylori is essential.

Honey and apoptosis in human gastric mucosa.

BACKGROUND: Gastric cancer is the fourth most common malignancy in the world. Honey is a complex mixture of special biological active constituents. Honey possesses antioxidant and antitumor properties. Nutritional studies have indicated that consumption of honey modulates the risk of developing gastric cancer. On the other hand, apoptosis has been reported to play a decisive role in precancerous changes. Our chief study was conducted to assess the relationship between consumption of honey and apoptosis in human gastric mucosa. METHOD: This cross-sectional study was conducted on 98 subjects over 18 years old, referred to two hospitals in Tabriz, Iran. Subjects were undergone an upper gastrointestinal endoscopy, 62 subjects were finally enrolled. Honey consumption was assessed by a Food Frequency Questionnaire (FFQ) and apoptosis was detected by TUNEL technique. We tested polynomial curve to find the best fit between honey consumption and apoptosis. RESULTS: A positive relation between honey consumption and apoptosis was found (P=0.024). Our results indicated that the final and the best fit curve was: apoptosis = 1.714+1.648(honey amount) - 0.533(honey amount)2 +1.833×10-5(honey amount)7. CONCLUSION: Honey consumption had positive effects on gastric cancer by inducing apoptosis in gastric mucosa.

The frequency of hepatitis D virus in patients with hepatitis B in Iran: an increasing rate?

This study sought to determine the seroprevalence of the hepatitis D virus (HDV), the risk factors and its association with the severity of liver disease. Continuous patients at Tabriz and Tehran Hepatitis Clinics were enrolled during 2007-2008 in a cross-sectional study. Demographic data and possible risk factors for infection were recorded for all hepatitis B surface antigen positive patients. The blood samples of 847 patients infected with the hepatitis B virus were evaluated. The seroprevalence of HDV was 9.3%. This rate was significantly higher after reaching 40 years of age. The rate was 12.7% in patients with chronic hepatitis B and 4.7% in patients with in-active hepatitis B; the difference was statistically significant. A history of dental interventions and several trips abroad were good predictors of HDV infection in logistic regression. No significant difference in liver function tests was found. The seroprevalence of HDV was higher than in some other studies from Iran but a decrease was noted in younger age.

Cancer in East Azerbaijan, Iran: results of a population-based cancer registry.

BACKGROUND AND AIMS: Regardless of the fact that cancers of GI tract have been reported to be the most common fatal neoplasms in East Azerbaijan, there is a serious lack of population-based studies in this region. METHODS: A comprehensive search was therefore undertaken to prospectively register all cases of cancer occurring in the province during March 2006-2007. Diagnosis of cancer was based on histopathology of primary lesions in 84.0% of cases, clinical investigation and ultrasound in 7.2%, only clinical investigation in 5.4%, and histology of metastasis in 2.9. Less than 1% were based on cytology and death certificates in one official year. RESULTS: A total of 4,922 cancers (mean age 60.2+18.13 years) were diagnosed during this population-based study. Of these, 56.8% (2114) were in males. ASRs for all cancers in males and females were 164.3 and 130.6 respectively. The top five sites for cancer in males (excluding skin cancer) according to the calculated ASR (world) were stomach (26.0), bladder (15.7), esophagus (12.4), colon and rectum (11.6) and blood (10.8); in females, they were breast (23.5), esophagus (11.7), stomach (11.6), colon and rectum (9.7) and nervous system (5.5). CONCLUSION: This first comprehensive report on cancer incidence in East Azerbaijan, documents particularly high incidence rates for esophageal and gastric cancer across the sexes.

Hepatitis C virus genotypes in patients with end-stage renal disease in East Azerbaijan, Iran.

Information about the genotypes and associated risk factors in hepatitis C virus (HCV) infected patients in Iran is limited. The aim of this study was to identify the HCV genotypes and associated risk factors in a group of HCV infected patients on dialysis therapy in Iran. The sera of 753 patients with chronic renal failure from fifteen dialysis units in East Azerbaijan Province were screened for anti-HCV antibodies as well as HCV RNA; viral RNA was extracted for the genotype specific primer approach. Patients were questioned concerning documented risk factors. Genotyping analysis was performed in 55 patients with positive anti-HCV and HCV-RNA. Genotypes 1 and 3 were found in 46 (83.7%) and three (5.5%) patients, respectively. The most frequent HCV subtype was 1a (76.4%), followed by 3a and 1b and 1b (5.5% each) while one patient was infected with both 1a and 1b. There was no statistically significant difference between the risk factors analyzed and the acquisition of HCV infection. This study gives added evidence of the predominant HCV genotypes in Iran, which is different than reports from other Arab countries and similar with the pattern of genotype in both Europe and United States.

Portal hemodynamics as predictors of high risk esophageal varices in cirrhotic patients.

AIM: To evaluate portal hypertension parameters in liver cirrhosis patients with and without esophageal varices (EV). METHODS: A cohort of patients with biopsy confirmed liver cirrhosis was investigated endoscopically and with color Doppler ultrasonography as a possible non-invasive predictive tool. The relationship between portal hemodynamics and the presence and size of EV was evaluated using uni- and multivariate approaches. RESULTS: Eighty five consecutive cirrhotic patients (43 men and 42 women) were enrolled. Mean age (+/- SD) was 47.5 (+/- 15.9). Portal vein diameter (13.88 +/- 2.42 vs 12.00 +/- 1.69, P < 0.0005) and liver vascular index (8.31 +/- 2.72 vs 17.8 +/- 6.28, P < 0.0005) were found to be significantly higher in patients with EV irrespective of size and in patients with large varices (14.54 +/- 1.48 vs 13.24 +/- 2.55, P < 0.05 and 6.45 +/- 2.78 vs 10.96 +/- 5.05, P < 0.0005, respectively), while portal vein flow velocity (13.25 +/- 3.66 vs 20.25 +/- 5.05, P < 0.0005), congestion index (CI) (0.11 +/- 0.03 vs 0.06 +/- 0.03, P < 0.0005), portal hypertensive index (2.62 +/- 0.79 vs 1.33 +/- 0.53, P < 0.0005), and hepatic (0.73 +/- 0.07 vs 0.66 +/- 0.07, P < 0.001) and splenic artery resistance index (RI) (0.73 +/- 0.06 vs 0.62 +/- 0.08, P < 0.0005) were significantly lower. A logistic regression model confirmed spleen size (P = 0.002, AUC 0.72) and portal hypertensive index (P = 0.040, AUC 0.79) as independent predictors for the occurrence of large esophageal varices (LEV). CONCLUSION: Our data suggest two independent situations for beginning endoscopic evaluation of compensated cirrhotic patients: Portal hypertensive index > 2.08 and spleen size > 15.05 cm. These factors may help identifying patients with a low probability of LEV who may not need upper gastrointestinal endoscopy.

An inverse relation between CagA+ strains of Helicobacter pylori infection and risk of erosive GERD.

OBJECTIVE: The aim of this study is investigating the association of Helicobacter pylori (H. pylori) infection and its cytotoxic-associated gene A (cagA) strain with reflux esophagitis. METHODS: In a case-control setting (May 2005-2006), patients with reflux esophagitis (case group) were compared with age and gender matched people suffering from symptoms of gastroesophageal reflux disease with normal upper gastrointestinal endoscopic findings (control group) in Imam Khomeini Hospital, Tabriz, Iran. The rates of H. pylori and its cagA positive infections were separately compared between the 2 groups and the subgroups with different severity of reflux esophagitis. RESULTS: Ninety-two and 93 patients were enrolled in the case and the control groups. The rate of H. pylori infection was insignificantly lower in the case group (81.5% versus 87.10%, p=0.29, odd ratio 0.654, 95% Confidence interval [CI] 0.293 to 1.495). The CagA positive infections were found significantly more frequent in the control group (59.1% versus 40.2%, p=0.01, odd ratio 0.465, 95% CI 0.258 to 0.836). There was no significant difference between the severity subgroups of the disease for H. pylori (p=0.30) or cagA positive infection rates (p=0.40). CONCLUSION: The CagA positive strains might have a protective effect against reflux esophagitis.

Five personality dimensions in patients with irritable bowel syndrome.

AIM: Irritable bowel syndrome (IBS) as a functional disorder of the gastrointestinal tract has been related to psychological factors. Aim of this study is to study the differences of personality factors between IBS patients compared to our general population. METHODS: This study was performed in clinics of Tabriz Medical University during 2006-2007. IBS was diagnosed using the Rome II diagnostic criteria after exclusion of organic bowel pathology. The entry of each patient was confirmed following a psychiatric interview and after any comorbid psychiatry disorder was ruled out. Personality traits and score of each factor was evaluated using NEO five factor personality inventory compared to results of a previous study on general population of Iran. RESULTS: One hundred and sixty six patients were studied. The mean age (+/-SD) of them was 33.6(+/-11.4) years (60.8% female). Our study population had their symptoms for a mean interval of 47.3 month. The bowel problems were provoked by distress in more than 80% of patients. Pain in female patients was reported to be more frequent but both gender described the association between stressors and their symptoms. NEO Five-Factor Inventory showed a significantly higher level of neuroticism and conscientiousness and lower level of openness and agreeableness in theses nonpsychiatric IBS patients. Women with IBS had significantly higher levels of openness, conscientiousness, and extraversion compared to men. CONCLUSION: Differences were observed between IBS patients and general population. Patients with IBS may benefit from psychological interventions.

Personality factors and profiles in variants of irritable bowel syndrome.

AIM: To study the association between irritable bowel syndrome (IBS) variants (constipation, diarrhea, or both) and personality traits in non-psychiatric patients. METHODS: IBS was diagnosed using the Rome II diagnostic criteria after exclusion of organic bowel pathology. The entry of each patient was confirmed following a psychiatric interview. Personality traits and the score of each factor were evaluated using the NEO Five Factor Inventory. RESULTS: One hundred and fifty patients were studied. The mean age (+/- SD) was 33.4 (+/- 11.0) year (62% female). Subjects scored higher in neuroticism (26.25 +/- 7.80 vs 22.92 +/- 9.54, P < 0.0005), openness (26.25 +/- 5.22 vs 27.94 +/- 4.87, P < 0.0005) and conscientiousness (32.90 +/- 7.80 vs 31.62 +/- 5.64, P < 0.01) compared to our general population derived from universities of Iran. Our studied population consisted of 71 patients with Diarrhea dominant-IBS, 33 with Constipation dominant-IBS and 46 with Altering type-IBS. Scores of conscientiousness and neuroticism were significantly higher in C-IBS compared to D-IBS and A-IBS (35.79 +/- 5.65 vs 31.95 +/- 6.80, P = 0.035 and 31.97 +/- 9.87, P = 0.043, respectively). Conscientiousness was the highest dimension of personality in each of the variants. Patients with C-IBS had almost similar personality profiles, composed of higher scores for neuroticism and conscientiousness, with low levels of agreeableness, openness and extraversion that were close to those of the general population. CONCLUSION: Differences were observed between IBS patients and the general population, as well as between IBS subtypes, in terms of personality factors. Patients with constipation-predominant IBS showed similar personality profiles. Patients with each subtype of IBS may benefit from psychological interventions, which can be focused considering the characteristics of each subtype.

Prevalence and precipitating factors of gastroesophageal reflux disease in a young population of Tabriz, Northwest of Iran.

OBJECTIVE: To estimate the prevalence and clinical spectrum of gastroesophageal reflux disease (GERD) in a young population and evaluate the risk factors. METHODS: This cross-sectional study using a reliable and valid questionnaire was performed during June and July 2005, on randomized selection of 620 students form Azad University of Tabriz. Gastroesophageal reflux disease was defined as at least weekly heartburn and/or acid regurgitation. RESULTS: Mean age (+/- SD) of the responders was 22.48 +/- 1.98 years. The prevalence of heartburn and/or acid regurgitation experienced at least weekly was 6.3% and monthly was 13%. The severity of symptoms was mainly of a mild to moderate degree. There was no difference in prevalence of any GERD symptom between 2 genders and it was not associated with age of the study population. A frequent symptom of GERD was reported more among subjects with atypical symptoms. There was no relation between marriage status and prevalence of GERD. On the other hand, GERD was less common among subjects with no family history of upper gastrointestinal disease and students in higher rank fields. Increased body mass index (but no recent weight gain or lose) and drinking coffee and tea was associated with higher prevalence of GERD symptoms. CONCLUSION: This study as the first study using a valid questionnaire reveals a high prevalence of frequent GERD symptoms in a young population of Tabriz. Atypical symptoms should be considered in this area.