Prevalence of gastroesophageal reflux disease in Moscow

Summary

Limited data exist to determine the prevalence and clinical spectrum of gastroesophageal reflux disease (GERD) in the Russian population, which might be different from those in Western countries. This study was performed in Moscow on randomized 1065 adults aged ≥15 years. A validated reflux questionnaire comprising 72 questions and an additional 29 sub-questions were used. The questions assessed (heartburn and regurgitation) and related (dyspepsia, dysphagia, odynophagia and chest pain) symptoms, the triggering factors of these symptoms, family history and data on demographic and socioeconomic features. GERD was defined as heartburn and/or regurgitation once a week or common. Of the 1065 participants, 42.1% were male and 57.9% were female. The prevalences of frequent and occasional symptoms were 17.6 and 22.1% for heartburn and 17.5 and 21.8% for regurgitation, respectively, over the last 12 months. The prevalence of GERD was found to be 23.6%. The rate of GERD was significantly higher in females than in males (15.4 vs. 29.5%, P < 0.001) and significantly increased as the age of the participants increased (P = 0.011). GERD was present in 20.4% of smokers, 24.2% of coffee drinkers, 21.5% of alcohol consumers and 45.9% of stressed participants. Although the rate of alcohol consumers was lower in those with GERD compared with those without GERD, the rate of coffee drinkers and stressed participants was higher among those with GERD. The rate of additional symptoms was higher even in participants complaining of regurgitation/heartburn rarely, compared with those without complaints. Using the same questionnaire, which makes it possible to compare the present results with those from different countries, we found the prevalence of GERD in Moscow to be 23.6%, one of highest in the Western populations. The rates of heartburn and regurgitation were found to be similar, which constitutes a different result than has been found in similar studies. Additional symptoms should be assessed, in all GERD patients even in the presence of rare complaints of regurgitation/heartburn.

Introduction

Gastroesophageal reflux disease (GERD) is one of the most common diseases in modern populations. An increased prevalence is associated with numerous factors, including lifestyle changes, such as nutritional habits, and obesity.¹ Although the number of investigations about debatable association between Helicobacter pylori infection and GERD has continued to rise, large epidemiological studies have reported an inverse association.² Other conditions that have been linked to GERD include dietary indiscretion, coffee, smoking and alcohol use. The role of certain medications, such as nonsteroidal anti-inflammatory agents, in GERD still requires critical evaluation.¹

GERD appears to be significantly more common in Western countries. The prevalence of GERD has been shown to increase in the last decade; if GERD is defined as reflux occurring twice weekly over several months, it has been estimated to affect 10–20% of the Western populations and 5% of the Asian population.¹ Recent studies have reported that the prevalence of GERD has also been increasing in Asian countries.³ Genetic, demographic and behavioral factors influence the incidence and course of the disease. Gastrointestinal, pulmonary, laryngeal, metabolic, neurological and psychiatric conditions have been linked to GERD.⁴ Despite the absence of standard criteria for diagnosis, several symptom-based diagnostic questionnaires and criteria have been defined.^2,3,5,6 It is difficult to compare the results of studies and to evaluate the differences between countries due to differences between questionnaires.

Detailed population-based data regarding the prevalence and symptom profile of GERD in Russia are limited. To the best of our knowledge, there is no related study published in English literature. The aim of the present study was to determine the prevalence and clinical spectrum of GERD in the Russian population in Moscow, which is one of the biggest cities in the world, as it is very possible that these data would differ from those in Western countries.

Materials and Methods

The study was performed in Moscow between February 2003 and April 2004. Assuming a maximum GERD prevalence of 20% in this population, a sample size consisted of 1065 adults (99% confidence interval, with a worst acceptable of ±3%) and their addresses were randomly selected from the white pages. Subjects aged ≥15 years were included, and those who had died or moved away from the city before the interview, possessed any mental or psychiatric disease, were unable to communicate due to dementia or refused to complete the survey were excluded. The population of Moscow grew rapidly between 1918 and 1990. However, because then, the population has declined due to a decreasing birth rate and increased migration away from the city, particularly in the early 1990s. Despite this decrease, according to the results of the national census in 2002, Moscow has remained the largest city in the Russian Federation, with a population of 10.4 million or approximately 7.2% of the Federation's total population of 143.5 million.

We used a reflux questionnaire derived from et al.⁶ It was previously validated in an English-speaking Western culture and then translated into the Russian language; after which, it was linguistically validated and adapted to the cultural profile of Moscow. As a summary, the process of translation included independent translation, back translation, a pilot test using 25 subjects, and review and approval from the original questionnaire developers. Feasibility was assessed in terms of the percentage of nonresponse and missing values, difficulty ratings (interviewer and interviewee) and administration time. Test–retest reliability was analyzed for each respondent using the Cohen's kappa coefficients in a sub-sample who repeated the interview 2–3 weeks after the first administration. The test–retest reliability of the Russian version of the questionnaire was good, and the Cronbach's alpha values were all higher than 70% for all major symptoms within the 12-month period of prevalence. Frequent symptoms were defined as an episode of one of the major symptoms occurring at least once a week. Occasional symptoms were defined as an episode of one of the major symptoms occurring less than once a week within the past 12 months. Subjects were determined to have GERD if they had heartburn and/or regurgitation once a week or common.

The questionnaire was administered through face-to face interviews at the Central Research Institute of Gastroenterology after an invitation via telephone. The total questionnaire contained 72 questions plus an additional of 29 sub-questions. The questions included major (heartburn and regurgitation) and related (dyspepsia, dysphagia, odynophagia and chest pain) symptoms, triggering factors of these symptoms, such as related medical conditions and past medical history, family history, and demographic and socioeconomic data, including the number of households and children, total monthly income, age, weight, height, employment, level of education and marital status. Past medical history included upper (nausea, vomiting and belching) and lower gastrointestinal symptoms (abdominal pain or discomfort); respiratory, throat and cardiac problems; the number of physician visits and diagnostic procedures related to upper gastrointestinal symptoms, medication usage (nonsteroidal anti-inflammatory drug, acetylsalicylic acid and all drugs that have been related to upper gastrointestinal complaints or other health problems); pregnancy; present or previous smoking; and consumption of alcohol, regular coffee or tea.

Data were analyzed using the Statistical package for the Social Sciences (SPSS Inc., Chicago, IL, USA) version 15.0. Categorical variables were expressed as frequency tables. Categorical comparisons between the groups were performed using cross-table statistics, and the significance level was analyzed by the chi-squared test. The statistical significance level was considered P < 0.05.

Results

Out of 1065 participants, 42.1% were male and 57.9% were female. The general characteristics of the participants are summarized in Table 1.

The prevalences of frequent and occasional symptoms were 17.6 and 22.1% for heartburn and 17.5 and 21.8% for regurgitation, respectively, within the last 12 months. The prevalence of GERD (presence of heartburn and/or regurgitation at least once in a week) was 23.6% (Fig. 1).

The rates of GERD were significantly higher in females than in males (29.5 vs. 15.4%, P < 0.001). With regard to the rate of GERD among age groups, it was the lowest in the 15- to 24-year-old age group (7.5%) and the highest in the >75-year-old age group (28.4%). The increases in the rate of GERD became significant as age increased (P = 0.011). The rate of GERD was 20.6% among married participants, 24.7% among singles and 31.6% among divorced/widowed participants and showed significant differences across these marital status groups (P = 0.005). However, no significant difference was found across the education level groups in the rate of GERD (P = 0.318). The rate of GERD in monthly income groups was significantly higher among with a monthly income lower than $50 (31.0%) compared with the other groups (P = 0.039). The rate of GERD showed no significant difference between the groups with body mass index (BMI) <30 and ≥30 kg/m² (P = 0.095; Fig. 2).

Although 63.8% of the participants were drinking alcohol and 34% were smoking, GERD was present in 20.4% of smokers, 24.2% of coffee drinkers, 21.5% of alcohol consumers and 45.9% of stressed participants. Although the rate of alcohol consumption was lower in those with GERD compared with those without GERD, the rates of coffee drinking and high stress were higher in those with GERD. The rate of smokers was similar in the groups with and without GERD (Table 2).

The rate of medication use was similar in the groups with and without GERD (Table 3). However, only 10% of subjects were currently taking antacids or acid inhibitors.

The rates of additional symptoms among the groups rated for regurgitation/heartburn occurrence (none, rare and frequent) are presented in Table 4. The rates of most of the additional symptoms were significantly higher in participants with rare or frequent regurgitation/heartburn compared with the participants with no typical symptoms.

Discussion

The symptoms and prevalence of GERD vary between Western and Eastern populations.^7–9 It has also been reported that the prevalence of GERD is lower in East, although recent increases have been found in some countries. It is thought that certain genetic and environmental factors protect the Asians against GERD; however, it has been reported that this balance is changing in recent times due to economic globalization and lifestyle changes.¹⁰

The absence of consensus on the definitions and diagnostic criteria for GERD is one of the causes behind the differences in the epidemiological data reported from different regions of the world. Although heartburn is predominant in Western countries, with symptoms varying among regions,¹¹ regurgitation is more common in Eastern countries.^12–14 In the review by Delaney,¹² heartburn was reported as a common symptom in Europe, with a prevalence ranging from 38% in Northern Europe to 9% in Italy.

Studies about the epidemiology of GERD performed with Mayo Questionnaire are summarized in Table 5.^{15,16,17,18,19,20,21,22} Except very low figures from China and Spain, prevalence rates were between 18 and 26.2%. Current study represents one of the highest prevalence rates following the USA. The original study using Mayo Questionnaire was performed by Locke et al. in 1.511 subjects by mail with a response rate of 73%.¹⁷ If symptom frequency was taken once a week or common, heartburn was more common than regurgitation (19.8 and 6.3%, respectively). The prevalence of heartburn, but not regurgitation, was decreasing by age. Their results have been found different than our study in both aspects. The coinvestigators of this research performed a prevalence study in low-income population in Turkey and found the prevalence of GERD symptoms to be 10% for heartburn, 15.6% for regurgitation and 20% for either symptom, experienced at least weekly.¹⁵ In the present study, the GERD prevalence was found to be 23.6% in the general population in Moscow. We observed neither a heartburn nor a regurgitation predominance. The prevalences of frequent and occasional symptoms were 17.6 and 22.1% for heartburn and 17.5 and 21.8% for regurgitation, respectively. Kennedy and Jones evaluated 3169 subjects with a dyspepsia questionnaire and defined GERD at least six episodes of heartburn and/or regurgitation within last year. The yearly prevalence of GERD was 28.7% in this study from United Kingdom.²³

Studies investigating the risk factors for GERD have shown different results. The relationship between GERD and BMI, tobacco/alcohol consumption, age, gender predominance and income was summarized in Table 6 in studies performed with Mayo Questionnaire. In general, although a relationship between BMI and age was observed, interestingly, income was inversely related with GERD. None of the studies showed a male predominance. In the present study, the rate of GERD was higher in females than in males (29.5 vs. 15.4%, P < 0.001). The prevalence increased with age, with the lowest in the 15- to 24-year-old age group (7.5%) and the highest in those with >75 years of age (28.4%).

Additional symptoms of GERD deserve special attention. In the present study, additional symptoms and gastrointestinal disorders were significantly higher in patients with GERD compared with those without GERD. Of the patients with GERD, 60.2% had dyspepsia; 53.8% had nausea; and 43% had belching. Dysphagia, globus, emesis, cough, symptoms of chronic pharyngitis and laryngitis were also present in more than 20% of GERD patients. The rate of additional symptoms was higher even in patients complaining of regurgitation/heartburn rarely compared with those without complaints. This suggests that additional symptoms should be assessed, even in the presence of rare complaints of typical symptoms. Table 7 summarizes the prevalence of additional symptoms in studies using the same questionnaire and diagnostic criteria. Although some studies have shown tremendous differences such as dyspepsia, in general, the prevalence of additional symptoms were significantly higher in patients with GERD compared with subjects without typical symptoms. It is difficult to explain the reasons of the different results from studies even they all use the same validated questionnaire and similar diagnostic criteria and no study has been performed to clarify those differences. Sociocultural characteristics, linguistic differences might play a role as well as dietary factors, Helicobacter pylori, genetic factors, BMI etc.

In conclusion, using the same questionnaire makes it possible to compare results from different countries. In the present study population, which has socio-culturally different characteristics from Western populations, the prevalence of GERD was found to be 23.6%, one of the highest that found in Western countries. The present study also demonstrated that GERD prevalence increased with age and was higher in females. Additionally, the prevalence of GERD was also found to be higher in widows and in those with low incomes. Although approximately 2/3 of the study population consumed alcohol, alcohol consumption was found to be lower in those with GERD compared with those without GERD. Further studies from non-Western cultures with different sociocultural characteristics might add new data to the current knowledge about GERD.

Acknowledgments

We appreciate for the support of Oktay Ozdemir MD (Yorum Danışmanlık. İSTANBUL).

References

Author notes