Gastroesophageal reflux disease and overall and cause-specific mortality: a prospective study of 50000 individuals

BACKGROUND Only a few studies in Western countries have investigated the association between gastroesophageal reflux disease [GERD] and mortality at the general population level and they have shown mixed results

This study investigated the association between GERD symptoms and overall and cause-specific mortality in a large prospective population-based study in Golestan Province, Iran

METHODS: Baseline data on frequency, onset time, and patient-perceived severity of GERD symptoms were available for 50001 participants in the Golestan Cohort Study [GCS]

We identified 3107 deaths [including 1146 circulatory and 470 cancer-related] with an average follow-up of 6.4 years and calculated hazard ratios [HR] and 95% confidence intervals [CI] adjusted for multiple potential confounders

RESULTS: Severe daily symptoms [defined as symptoms interfering with daily work or causing nighttime awakenings on a daily bases, reported by 4.3% of participants] were associated with cancer mortality [HR 1.48, 95% CI: 1.04-2.05]

This increase was too small to noticeably affect overall mortality

Mortality was not associated with onset time or frequency of GERD and was not increased with mild to moderate symptoms

CONCLUSION: We have observed an association with GERD and increased cancer mortality in a small group of individuals that had severe symptoms. Most patients with mild to moderate GERD can be re-assured that their symptoms are not associated with increased mortality

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

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

Effect modification in epidemiology and medicine

Effect modification, also known as interaction or heterogeneity of effect, is an important concept in epidemiology. This article reviews the definition and types of effect modification, methods to detect effect modification, the reasons for observing effect modification in epidemiologic studies, the importance of choice of model in finding effect modifiers, and effect modifications that are important to public health

Vitamin and mineral supplements: do we really need them?

In the United States, 40-50% of the men and women 50 years of age or older regularly use multivitamin/mineral [MVM] supplements, making the annual sales of these supplements over $11 billion. However, the question remains whether using MVM supplements is beneficial to health. This article reviews the results of randomized studies of MVM supplements and individual vitamins/mineral supplements in relation to overall mortality and incidence of chronic diseases, particularly cancer and ischemic heart disease. The results of large-scale randomized trials show that, for the majority of the population, there is no overall benefit from taking MVM supplements. Indeed, some studies have shown increased risk of cancers in relation to using certain vitamins

Squatting and risk of colorectal cancer: a case-control study

The sitting position, rather than squatting, during defecation has been hypothesized to be a risk factor for colorectal cancer [CRC]. We conducted a case-control study to test this hypothesis.A total of 100 CRC cases from two hospitals in Iran and 100 control subjects, selected from the coronary care unit [CCU] of those same hospitals were selected for this study. We administered a detailed questionnaire to the study subjects asking about history of toilet use and other relevant confounders. In logistic regression analysis, the crude and adjusted ORs [95% CIs] for using sitting toilets in any decade were 1.20 [0.89 - 1.61] and 1.07 [0.72 - 1.59], respectively. Also, the crude and adjusted ORs [95% CIs] for using 10 more years of sitting toilets were as 1.16 [0.92 -1.47] and 1.02 [0.74 - 1.40], neither of which indicated a statistically significant increase in risk. Our study did not support an appreciable role for using sitting toilets as risk factors for CRC

Causality in epidemiology

This article provides an introduction to the meaning of causality in epidemiology and methods that epidemiologists use to distinguish causal associations from non-causal ones. Alternatives to causal association are discussed in detail. Hill's guidelines, set forth approximately 50 years ago, and more recent developments are reviewed. The role of religious and philosophic views in our understanding of causality is briefly discussed

Effectiveness and feasibility of lifestyle and low-cost pharmacologic interventions in the prevention of chronic diseases: a review

Chronic diseases are already major causes of morbidity and mortality in Iran, similar to what is seen in other countries. However, there doesn't yet exist a comprehensive plan to cope with the epidemic of chronic diseases in Iran. Several lifestyle and low-cost pharmacological interventions have been proposed to reduce the burden of chronic diseases. Lifestyle interventions require a comprehensive infrastructure that can be quite costly in this country, but several components of extensive lifestyle interventions, including self-help materials and brief advice by health workers, can be integrated into the existing system. Pharmacological interventions may have substantial contribution to the capacity and preparation of Iran's healthcare system to confront the epidemic of chronic diseases. Further research needs to be performed to determine the feasibility and efficacy of each of these methods in order for policy makers to take the appropriate measures on adopting each of these strategies to prevent and control chronic diseases

Helicobacter pylori and its effects on human health and disease

H.pylori is now a known cause of gastric and duodenal ulcers, noncardia gastric cancer and gastric MALT lymphoma. In addition, the role of this microorganism in causing or preventing a larger number of other diseases has been investigated, some of which include esophageal cancer, functional dyspepsia, gastroesophageal reflux disease, asthma, cardiovascular diseases, iron deficiency anemia and idiopathic thrombotic purpura. This article review the evidence for these associations and provides suggestions for further research