Helicobacter pylori (H pylori) is a gram-negative, pronate, spiral, and micro-europhilic bacterium with excremental–oral and or oral-oral transmission to human (Grunert, 2005). H pylori has been known as one of the most prevalent human chronic infections in half of the world population, which is the major factor in the outbreak of several diseases such as gastric cancer (Ajdarkosh et al., 2015). This is the fourth prevalent malignancy in the world and the second cause of death due to cancer in the world (Modaresi-Esfeh et al., 2011). H pylori as both initiating and effective factor in gastric cancer progress was entitled death offshoot (Lee and Derakhshan, 2013). Prevalence of H pylori infection reaches 25-50% in advanced countries and to more than 80% in the developing countries (Talebibezminabadi, 2013). Based on the conducted studies, the prevalence rate of H pylori in Asia (Talebibezminabadi, 2013) and Iran (Miwa et al., 2015, Modaresi-Esfeh et al., 2011) was estimated at approximately 90%. H pylori infection can enter human stomach, due to the neonatal period and remains asymptotic for years in most cases (Grunert, 2005). Asia- Oceania health regulations adjustment association strategies has recently stated that H pylori infection should be extensively screened and treated in order to reduce the gastric cancer risk in high-risk populations (Fuccio et al., 2008). It should be mentioned that H pylori is accepted by scientists as an index for predicting the possibility of suffering from gastric cancer (Uemura et al., 2001) and no vaccine has been discovered and prepared for it (Matysiak-Budnik and Mégraud, 2006).
Conversely, food insecurity has been known as the public health dilemma in the world and considered by health policy makers (Jamieson et al., 2013). Food insecurity status is different in various regions of the world and even in Iran. For instance, in numerous studies, the unsafe food rates consumed by Iranian people (including healthy and ill) were 20-42.5% in Tehran (World Health Organization, 2010, Zerafati_Shoae et al., 2007) and 44% in Shiraz (Ramesh et al., 2010). The prevalence of food insecurity had a direct and significant relationship with low income, unemployment, low educations, increase of household size, increase of the number of children, and increase of the epidemic and non-epidemic diseases like heart diseases and depression (Boyle‐Baise, 1998, Kendall et al., 1995, Mohammadzadeh et al., 2010, Nord et al., 1999, Seligman et al., 2009, World Health Organization, 2010). In Iran, these relationships have been strongly observed; they indicate the potential effect of environmental factors on the creation of food insecurity (Dastgiri et al., 2006, Hakim et al., 2011, Mohammadi et al., 2008, Omrani et al., 2013, Rahim et al., 2011, Zerafati_Shoae et al., 2007). In addition, increasing prevalence
of H pylori infection was high in low social- economic healthy levels of human societies (Mohammadzadeh et al., 2010, Zerafati_Shoae et al., 2007).
The index of quality of life and dimensions of physical and mental health had a great relationship with human health (Kaptein et al., 2005). Mostly, patients' quality of life was examined by public measures (examination of disease symptoms and the physician report) and social dimensions of the quality of life were greatly overlooked. Moreover, the impact of social–mental factors on the outbreak of colon-brain interactions causes reduction of quality of life in digestive patients (Chang, 2004). Reduction of family income level, low educations, aging, and reduction of the health level had also a direct relation with reduction of quality of life (Chang, 2004, Gralnek et al., 2000, Mogharab et al., 2011, Omrani et al., 2013). However, weak social- economic and healthy status were related to increased prevalence of H pylori (Hosseini et al., 2012, Talebibezminabadi, 2013).Thus, according to the researchers, quality of life in patients with H pylori infection requires more systematic studies, especially as one of effective criteria in randomized clinical trials (Kaptein et al., 2005).
Considering the necessity of utilizing strategies for preventing cancer and scarcity of the related studies, this study was designed for discovering the relationship of food insecurity and quality of life with H pylori infection.
Materials and Methods
Study design and participants: The present case-control study was conducted in 2016 on people who referred to Imam Reza sub-specialist clinic affiliated to Shiraz University of Medical Sciences. The required sample size was obtained as 192 based on the study conducted by Modarresi et al. (2010) in Tabriz (Modaresi-Esfeh et al., 2011) and the participants were selected by convenient sampling method.
Short invitation letters were distributed among all clients of Imam Reza clinic. For accelerating and facilitating sampling, the individuals were also provided with a notification of free and voluntary participation in the study along with a complete explanation about the plan, exclusion and inclusion criteria, as well as the researcher's contact address and phone number at the health center's main entrance door and all floors.
For participating in the study, 360 persons volunteered and completed the inclusion criteria forms. The inclusion criteria included having 25-65 years of age, no addiction to smoking, drugs, and alcohol, as well as not suffering from incurable diseases (such as heart disease, diabetes, hepatic and renal diseases, and various types of cancer). Pregnant and breastfeeding women and those who had special nutrition habits such as mere vegetarian regimens were removed from the sample population.
Measurements: These people initially answered the questions and then were introduced to the laboratory. Some of the volunteers had the history of experiencing dyspepsia symptoms and had consumed digestive medicines without physician prescription. They were not aware of the existence of H pylori infection in their stomach and this issue made them to truly answer the questions without mental background from H pylori existence.
All volunteers were required to sign ethical consent forms for participating in the study. The questionnaires employed in the study were anonymous and general, family food insecurity and life quality questionnaires were completed for all volunteers by a skillful expert. General demographic specifications, including age, gender, education level, occupation, marital status, family dimension, and consumption of digestive medicines were asked and participants' weight and height were measured using standard methods. Body mass index (BMI) was also calculated using the formula of dividing weight (kg) by height square (m2) (Zerafati_Shoae et al., 2007). It should be stated that provision of individual consultation and diet were an act of appreciation for the participants' cooperation. Then, the Sample container for collecting feces were delivered to volunteers for diagnosis of H pylori antigen with Eliza method.
Among the people whose test results were positive, 100 persons were selected for the case group and among those whose result was negative, 100 were selected for the control group.
Food security in this study was investigated using family food security inventory of United States Department of Agriculture (USDA) (Mohammadzadeh et al., 2010). This inventory was validated for epidemiologic studies and its validity and reliability were confirmed in Iranian studies (Mohammadzadeh et al., 2011, Ramesh et al., 2010). This questionnaire examines the family food safety in the past 12 months. Based on the scores obtained, the individuals were classified in two the main classes of food secure (0-1.8) and food insecure (1.8-9.3) (Bickel et al., 2000).
One of the most common and comprehensive instruments for examining the participants' quality of life regarding health is the 36-question inventory “SF-36” (the Short Form Health Survey), which has been established as the golden standard. It calculates 8 multi-item scales of physical functioning, physical role, bodily pain, general health, vitality, social functioning, emotional role, and mental health. It also contains 2 summary scales of the physical component summary (PCS) and the mental component summary (MCS). The score obtained from each subscale can range between 0-100 and a score of mental and physical health varies between 0- 400. Finally, the obtained scores were interpreted in both dimensions qualitatively and quantitatively:
Scores below 100: bad quality of life; Scores 100-200: Average quality of life; Scores 200-300: good quality of life; Scores above 300: very good quality of life (Ware Jr and Gandek, 1998) . This scale was translated and validated in Iranian studies (Fouladvand et al., 2009, Montazeri and Vahdaninia, 2005).
Data analysis: Data were collected using SPSS software version 23 and analyzed by chi-square and independent t-test. For examining the joint impact of variables on each other, all variables with significant results in univariate analysis stage entered a multivariate logistic regression model in which the final independent variables were identified using backward method. The P-value of less than 0.05 was considered as the significance level.
Results
The prevalence rate of infection to H pylori was 28%. By comparing the case and control groups, no significant relation was observed between increase of H pylori infection risk and age, gender, family dimension, and BMI. However, a significant relationship was observed between the risk of H pylori infection and marital status, occupation, education, and background of consuming digestive medicines (Table 1).
Comparison of the two groups showed a significant difference with respect to food insecurity. Furthermore, the quality of life (generally) as well as physical and mental health showed a significant and reverse relationship with the possibility of suffering from H pylori infection (Table 2).
In backward logistic regression and in the presence of all variables which became significant in univariate analysis, the quality of life (generally) and medicine consumption background remained in the model (Table3).
The possibility of suffering from H pylori was 3.97 times higher in individuals who had a history of digestive medicines consumption (95% CI: 2.11-7.40). In addition, by reduction of life quality, the possibility of suffering from H pylori improved 1.77 times (95% CI: 1.20-2.59).
Discussion
Epidemiologic studies use various variables for assessing the relationship between quality of human life and its various effective factors such as suffering from diseases (Chang, 2004). In the present study, no relation was observed between female gender and suffering from
H pylori infection. In a study in Mashhad, the rate of
H pylori prevalence was equal in girls and boys (Keramati
et al., 2012).The results of other studies did not indicate any significant difference between men and women with respect to suffering from HP (Forman and Burley, 2006, Kargar
et al., 2013, Khodarahmi
et al., 2008, Mirzaei and Zahedi, 2015). In the present study, the age variable was considered in a fixed range in order to exclude its falsifying impact on other variables, since gastric cells atrophy and reduction of the body immune system power could make old people vulnerable to
H pylori infection (Grunert, 2005). The results indicated higher age average of people with
H pylori infection than the healthy people. However, the findings did not show any significant difference with respect to the comparison among the studied groups age average (Fakhr Yaseri
et al., 2005, Fuccio
et al., 2008, Rosenstock
et al., 2000) (7,39,40,41). The comparison of marital status between both groups revealed that infection of
H pylori was higher in married individuals. Previous studies reported that after one year follow-up of couples with or without infection and single people with
H pylori, wives of infected people became significantly infected with
H pylori, which could be due to the person to person transfer as a result of couple's usage of common resources and their reduction of individual health (Salih, 2009, Singh
et al., 1999). Moreover, a significant difference was found regarding occupational status between the two studied groups and most
H pylori infected people were householders. It was seen that parents' infection, especially mothers had a key role in transferring
H pylori infection to the child (Fakhr Yaseri
et al., 2005).
Education level was introduced as the most significant factor in
H pylori infection (Kendall
et al., 1995). In social groups with lower education, outbreak of
H pylori infection and other subsequent problems were significantly reported (Grunert, 2005, Mohammadzadeh
et al., 2010). Our results showed that the prevalence of
H pylori infection in people with academic education was significantly lower. A study on children revealed that the possibility of
H pylori infection was higher in parents with lower education level and greater family dimension (Mirzaei and Zahedi, 2015). It appears that income reduction and low educations make these people to stand in low social classes, which along with reduction in public health result in more suffering from infections such as
H pylori. Numerous studies reported significant increase of
H pylori infection risk in poor societies (Malaty
et al., 1998, Talebibezminabadi, 2013). The findings of previous studies stated a significant and direct relationship between increased possibility of
H pylori infection and increased household size (Mirzaei and Zahedi, 2015, Seligman
et al., 2009, World Health Organization, 2010). However, the present study could not show a significant relation between household size and possibility of
H pylori infection. In examining the household size, it was observed that when a child in a family is infected by
H pylori, the mother and other children's possibility of infection is about 75-80% (Rowland, 2000). Apparently, increase in the household size causes reduction of families' access to social and economic welfare, reduction of education and health level, and increase of infection possibility.
After comparing the background of medicines used in treating dyspepsia problems and digestive diseases, a significant and direct difference was found between the two studied groups. This relationship strongly states that although people with
H pylori infection in the present study were not aware of their infection,
H pylori infection directly increased their consumption of digestive medicines. Pilotto et al. showed a significant increase in digestive medicine consumption in people with dyspepsia (without microbe infection), various digestive diseases, and even cancers (Pilotto
et al., 2011).
In few studies, body weight and BMI were mentioned as an index for assessing the relationship with
H pylori infection (Zerafati_Shoae
et al., 2007). In the present study, no significant relation was observed between weight and
H pylori infection. In other words, people with
H pylori had lower weight average and BMI than healthy individuals, which could be as a result of their lower health and economic status. In some studies, BMI higher than normal was considered as the risk factor of
H pylori infection, but its mechanism is still not specified (Fuccio
et al., 2008). A meta-analysis stated that the BMI of
H pylori infected people was a little higher than that of the healthy individuals (Pilotto
et al., 2011). However, researchers of Persian Gulf healthy heart could not show a relationship between BMI and the risk of
H pylori infection (Ostovar
et al., 2014) .However, it appears that after
H pylori treatment, BMI raises significantly due to increased plasma ghrelin level, which results in improved appetite and higher stored body fat (Lane
et al., 2011, Nwokolo
et al., 2003).
A comparison of food insecurity status between the studied groups showed that food insecurity increased by increase of the
H pylori infection. No study is available for confirming or rejecting these results; so, this mechanism cannot be clearly explained. This result can be due to poorer social, economic, and health status of individuals with
H pylori infection compared with other participants of this study. Considering the prevalence of
H pylori on one hand and the prevalence of food insecurity on the other hand, both prevalence of
H Pylori and the prevalence of food insecurity in the lower social-economic classes was significant. It was also confirmed by our results; so, it can be said that food insecurity in these individuals has resulted increased
H pylori infection in the current studied group. Possibly, low income, social poverty, and reduction of access to health services resulted in an increase in food insecurity. Given the great differences of societies in food insecurity and prevalence of
H pylori infection, designing more comprehensive studies with larger samples is necessary for assessing the relationship between food insecurity and
H pylori infection.
The present study showed a significant and reverse relation between the possibility of
H pylori infection, quality of life, and both dimensions of physical and mental health. About 71% of individuals with
H pylori infection have bad and moderate life quality. This finding emphasizes the necessity of monitoring the poor social classes with respect to
H pylori infection and preventing them from serious complications such as digestive ulcers and gastric cancer. Of course, no study was available over the relation between
H pylori infection and quality of life. Although the case group individuals (
H pylori infected) in this study were not aware of their
H pylori infection, perhaps we can say that
H pylori infection complications reduced life quality score in their physical and mental health dimensions or vice versa. In other words, low level of life quality as well as physical and mental health have made them susceptible to
H pylori infection. Conversely, people with
H pylori infection in the present study were from weak classes of the society with low educations,
H pylori prevalence, and low level of life quality. In the present study, the relation between
H pylori infection and quality of life was reversely significant. Low income and social welfare increased neural pressures (mental health reduction) and reduction of stomach antioxidant capacity; so, the individual became vulnerable to
H pylori infection. This can be justified by saying that
H pylori existence causes reduction of vitamin C secretion to gastric juice and this mechanism can reduce gastric juice anti-oxidant capacity and helps in the extension of pre-cancerous symptoms (atrophy, metaplasia, and dysplasia) (Russo
et al., 2001). As a result of this infection, physical health and consequently life quality are reduced. Previous studies stated that 60% of patients with gastric ulcer had at least one severe mental pressure during their life and this issue indicates that mental changes precede physical alterations (Mogharab
et al., 2011). In spite of high prevalence of
H pylori infection in more than 93% of patients with duodenum ulcer, 80% of patients with gastric ulcer, and low level of quality of life in these patients (Kaptein
et al., 2005), it seems necessary for researchers to consider finding ways of reducing
H pylori infection risk and designing cohort studies. In examining quality of life in individuals with chronic diseases, Gralnek et al. used SF-36 inventory and showed that in patients with irritable bowel syndrome quality of life was significantly reduced owing to continuous annoying digestive symptoms (Gralnek
et al., 2000). Furthermore, a cross-sectional study showed that by increase of age, the score of physical health was reduced and by increase of education level, general score of both physical and mental health dimensions increased. In fact, increase in family income was accompanied with increase in mental health score (Omrani
et al., 2013). In numerous previous studies, the quality of life was merely reported by examining symptoms and function status instead of the disease consequences (Kaptein
et al., 2005). However, in the present study, SF-36 inventory was employed as a golden standard for examining quality of life in healthy and ill people.
The limitation of the present study was lack of multilateral dominance owing to food increase, reduction of life quality score, and obscure relations of these indexes with other demographic and health specifications of studied people. In this way,
H pylori infection caused reduction of life quality and increased food insecurity or vice versa. Perhaps this study could not obviously show or interpret the results obtained from the present results, because there are always some limitations in scientific studies
Conclusion
In conclusion, the prevalence of
H pylori was significantly higher in married people, householder women, and people with low levels of education. In addition, the history of digestive medicines was higher in
H pylori infected people and showed the greatest correlation among the examined indexes in the study. In the
H pylori infected population, food insecurity significantly increased and the quality of life reduced in both dimensions of physical and mental health. Thus, we hope that
H pylori infection can be reduced by enhancing social-economic and health conditions such as improving food insecurity status and quality of life in the societies, especially the weak social classes. On the contrary, regarding high prevalence of
H pylori infection in various countries and weak classes of a society, especially Iran and in order to prevent its painful and expensive consequences including chronic digestive ulcers and gastric cancer,
H pylori screening performance and designing extensive studies are necessary for finding approaches to reduce
H pylori infection risk.
Acknowledgment
We appreciate all volunteers who participated in the study, manager of Imam Reza clinic and Vice-Chancellor for Research of Shiraz Medical Sciences University who funded this study costs. It should be mentioned that the present study was derived from an M.A thesis No. 93.7285.
Authors’ contributions
Talezadeh Shirazi S, Eftekhari MH and Mzloom Z designed and developed this study. Fararouei M analyzed the data. Ranjbar Zahedani M conducted the study, wrote the manuscript, and participated in the data collection. All authors read and approved the final manuscript.
Conflict of interest
There is not any conflict of interest.
References
Ajdarkosh H, et al. 2015. Prevalence of gastric precancerous lesions among chronic dyspeptic patients and related common risk factors.
European journal of cancer prevention. 24 (5): 400-406.
Bickel G, Nord M, Price C, Hamilton W & Cook J 2000. Guide to Measuring Household Food Security Alexandria. VA US Department of Agriculture (USDA) Food and Nutrition Service Office of Analysis N, and Evaluation.
Boyle‐Baise M 1998. Community service learning for multicultural education: An exploratory study with preservice teachers.
Equity & Excellence. 31 (2): 52-60.
Chang L 2004. Epidemiology and quality of life in functional gastrointestinal disorders.
Alimentary pharmacology & therapeutics. 20: 31-39.
Dastgiri S, Mahboob S, Tutunchi H & Ostadrahimi A 2006. Determinants of food insecurity: a cross–sectional study in Tabriz.
Journal of Ardabil University of medical sciences. 6 (3): 233-239 (Persian).
Fakhr Yaseri H, Yadollahzadeh M & Hossein Nejad Yazdi MA, F 2005. Assessment of the Relationship between Helicobacter Pylori and Esophagitis in Patients with Gastritis Referred to Firoozgar Hospital (2002-2003).
Journal of Iran University of medical sciences. 11 (44): 1011-1018 (Persian).
Forman D & Burley V 2006. Gastric cancer: global pattern of the disease and an overview of environmental risk factors.
Best practice & research clinical gastroenterology. 20 (4): 633-649.
Fouladvand K, Valielah F, Shahrarai M & Sangari H 2009. Psychometric characteristics of Ware's mental and physical health questionnaire.
Fuccio L, Zagari RM & Bazzoli F 2008. What is the best salvage therapy for patients with Helicobacter pylori infection?
Nature reviews gastroenterology & hepatology. 5 (11): 608.
Gralnek IM, Hays RD, Kilbourne A, Naliboff B & Mayer EA 2000. The impact of irritable bowel syndrome on health-related quality of life.
Gastroenterology. 119 (3): 654-660.
Grunert KG 2005. Food quality and safety: consumer perception and demand.
European review of agricultural economics. 32 (3): 369-391.
Hakim S, Dorosty A & Eshraqian M 2011. Relationship between food insecurity and some of socioeconomic factors with BMI among women in Dezfoul.
Iranian journal of school of public health. 2: 55-66.
Hosseini E, Poursina F, Van de Wiele T, Safaei HG & Adibi P 2012. Helicobacter pylori in Iran: A systematic review on the association of genotypes and gastroduodenal diseases.
Journal of research in medical sciences: the official journal of Isfahan University of medical sciences. 17 (3): 280.
Jamieson JA, Kuhnlein HV, Weiler HA & Egeland GM 2013. Higher n3-fatty acid status is associated with lower risk of iron depletion among food insecure Canadian Inuit women.
BMC public health. 13 (1): 289.
Kaptein AA, Morita S & Sakamoto J 2005. Quality of life in gastric cancer.
World journal of gastroenterology. 11 (21): 3189.
Kargar M, Souod N, Ghorbani-Dalini S & Doosti A 2013. Epidemiological evaluation of Helicobacter pylori infection in patients with gastrointestinal disorders in Chahar Mahal and Bakhtiari province.
Journal of Fasa University of medical sciences. 2 (4): 266-272 (Persian).
Kendall A, Olson CM & Frongillo Jr EA 1995. Validation of the Radimer/Cornell measures of hunger and food insecurity.
Journal of nutrition. 125 (11): 2793-2801.
Keramati MR, et al. 2012. Role of the Lewis and ABO blood group antigens in Helicobacter pylori Infection.
Malaysian journal of medical sciences. 19 (3): 17.
Khodarahmi I, Rashidi A & Khodarahmi P 2008. Relationship between ABO blood groups and seroprevalence of Helicobacter pylori.
Indian journal of gastroenterol. 27 (2): 82-83.
Lane JA, et al. 2011. Randomised clinical trial: Helicobacter pylori eradication is associated with a significantly increased body mass index in a placebo‐controlled study.
Alimentary pharmacology & therapeutics. 33 (8): 922-929.
Lee YY & Derakhshan MH 2013. Environmental and lifestyle risk factors of gastric cancer.
Archives of Iranian Medicine. 16 (6).
Malaty HM, Graham DY, Isaksson I, Engstrand L & Pedersen NL 1998. Co-twin study of the effect of environment and dietary elements on acquisition of Helicobacter pylori infection.
American journal of epidemiology. 148 (8): 793-797.
Matysiak-Budnik T & Mégraud F 2006. Helicobacter pylori infection and gastric cancer.
European journal of cancer. 42 (6): 708-716.
Mirzaei SMS & Zahedi MJ 2015. Prevalence
of Helicobacter Pylori-negative, non-steroidal anti-inflammatory drug related peptic ulcer disease in patients referred to Afzalipour hospital.
Middle East journal of digestive diseases. 7 (4): 241.
Miwa H, et al. 2015. Evidence-based clinical practice guidelines for functional dyspepsia.
Journal of gastroenterology. 50 (2): 125-139.
Modaresi-Esfeh J, et al. 2011. The relationship between helicobacter pylori infection and dietary habits.
Journal of Kermanshah University of medical sciences 15 (3): 55-62 (Persian).
Mogharab M, et al. 2011. Prevalence of depression and life events in hemodialysis
patients in Vali-Asr hospital in Birjand (2010).
Modern care, scientific quarterly of Birjand nursing and midwifery faculty. 8 (3): 125-134 (Persian).
Mohammadi F, Omidvar N, Houshiar Rad A, Mehrabi Y & Abdollahi M 2008. Association of food security and body weight status of adult members of Iranian households.
Iranian journal of nutrition sciences & food technology. 3 (2): 41-53 (Persian).
Mohammadzadeh A, Dorosty A & Eshraghian M 2010. Household food security status and associated factors among high-school students in Esfahan, Iran.
Public health nutrition. 13 (10): 1609-1613.
Mohammadzadeh A, Dorosty A & Eshraghian M 2011. Household food security status and food consumption among high school students in Esfahan, Iran.
Iranian journal of epidemiology. 7 (1): 38-43 (Persian).
Montazeri A & Vahdaninia M 2005. Translation, reliability and validity of Persian standard tool sf-36. Quarterlypayesh.
Journal of the Iranian Institute for Health Sciences research. 5 (1): 45-56.
Nord M, Jemison K & Bickel G 1999. Prevalence of food insecurity and hunger, by state 1996-1998, Food Assistance and nutrition Research Report No. 2 Food and Rural Economics Division. In
Economic Research Services, United States Department of Agriculture.
Nwokolo C, Freshwater D, O’hare P & Randeva H 2003. Plasma ghrelin following cure of Helicobacter pylori.
Gut. 52 (5): 637-640.
Omrani HR, et al. 2013. Quality of Life and It’s Determinant in hemodialysis patients in Kermanshah in 2010.
Journal of Kermanshah University of medical sciences. 16 (8): 657-664 (Persian).
Ostovar A, et al. 2014. Hypertension risk and conventional risk factors in a prospective cohort study in Iran: The Persian Gulf Healthy Heart Study.
International journal of cardiology. 172 (3): 620-621.
Pilotto A, et al. 2011. Association of upper gastrointestinal symptoms with functional and clinical charateristics in elderly.
World journal of gastroenterology. 17 (25): 3020.
Rahim S, Saeed D, Rasool GA & Saeed G 2011. Factors influencing household food security status.
Food and nutrition sciences. 2 (01): 31.
Ramesh T, Dorosty A & Abdollahi M 2010. Prevalence of food insecurity in household of Shiraz and association with some of socioeconomic and population factors.
Iranian journal of nutrition sciences and food technology. 4 (4): 53-64 (Persian).
Rosenstock SJ, Jørgensen T, Andersen LP & Bonnevie O 2000. Association of Helicobacter pylori infection with lifestyle, chronic disease, body-indices, and age at menarche in Danish adults.
Scandinavian journal of public health. 28 (1): 32-40.
Rowland M 2000. Transmission of Helicobacter pylori: is it all child's play?
The Lancet. 355 (9201): 332-333.
Russo A, et al. 2001. Effect of lifestyle, smoking, and diet on development of intestinal metaplasia in H. pylori-positive subjects.
American journal of gastroenterology. 96 (5): 1402-1408.
Salih BA 2009. Helicobacter pylori infection in developing countries: the burden for how long?
Saudi journal of gastroenterology: official journal of the Saudi gastroenterology association. 15 (3): 201.
Seligman HK, Laraia BA & Kushel MB 2009. Food insecurity is associated with chronic disease among low-income NHANES participants.
Journal of nutrition. 140 (2): 304-310.
Singh V, et al. 1999. Helicobacter pylori: Evidence for spouse‐to‐spouse transmission.
Journal of gastroenterology and hepatology. 14 (6): 519-522.
Talebibezminabadi A 2013. Virulence factors and treatment of Helicobacter pylori infections. Utrecht University.
Uemura N, et al. 2001. Helicobacter pylori infection and the development of gastric cancer.
New England journal of medicine. 345 (11): 784-789.
Ware Jr JE & Gandek B 1998. Overview of the SF-36 health survey and the international quality of life assessment (IQOLA) project.
Journal of clinical epidemiology. 51 (11): 903-912.
World Health Organization 2010. Country cooperation strategy for WHO and Islamic Republic of Iran: 2010–2014.
Zerafati_Shoae N, et al. 2007. Is the adapted Radimer/Cornell questionnaire valid to measure food insecurity of urban households in Tehran, Iran?
Public health nutrition. 10 (8): 855-861.