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Gastroenterology Research

Original Article

Volume 2, Number 3, June 2009, pages 152-156

Gastroesophageal Reflux Disease: A Population Based Study

Gastroesophageal reflux disease (GERD) is a common disorder of the upper gastrointestinal tract with an incidence rate of 10% - 38% of adults in the western population occurring at least once a week [1, 2]. The prevalence has been increasing worldwide [3]. The disease affects the patients’ quality of life [4], reduces their functional activity [5], increases the economic burden [6] and predisposes them to more serious conditions as in Barretts esophagus and esophageal adenocarcinoma [7]_.

Information relating to the relationship between race and GERD is conflicting [8, 9]. Few population based studies are available from Africa but the available data suggest that in sub-Saharan Africa, GERD and its complications are rare [9]. Most studies on GERD in Nigeria were carried out on patients referred for upper gastrointestinal endoscopy [10-13]. In GERD, the dominant complaint is typically heartburn or acid regurgitation [14]. A patient-centered, symptom-driven approach to GERD assessment and diagnosis is currently recommended and it is independent of endoscopic findings [15].

Symptom analysis is a practical and inexpensive approach to the diagnosis of GERD. It enables identification of most patients with GERD who present with typical symptoms [1, 4]. This is the rationale for the increasing use of structured questionnaires in the diagnosis of GERD. The Carlsson-Dent questionnaire [16] has widespread acceptance, as in a Chinese report for the diagnosis of GERD [17]. The contents of the questionnaire are consistent with the Montreal definition and classification of GERD as articulated in a global evidence-based consensus [15].

This population-based study aimed at determining the prevalence of GERD and risk factors associated with it among medical students in a Nigerian medical school using the Carlsson-Dent questionnaire.

This was a cross-sectional questionnaire-based study of medical students in the clinical stage of their training at the College of Medicine, University of Nigeria, Enugu Campus. The study lasted from February 1, 2008 to April 30, 2008. Informed consent was obtained from all the participants and all consenting students were included. Students who were pregnant at the time of the study were excluded.

The Carlsson-Dent questionnaire was administered to all the participants. This is a 7-item questionnaire which utilizes a symptom description as well as symptom analysis. Numerical scores are assigned to specific components of the symptom analysis. These scores could be positive or negative. In the end the scores were summed to obtain a total score which ranged from -7 to +18. The severity of symptoms was also graded from 1 to 5 representing no problem at all, mild problem, moderate problem, severe problem and very severe problem. There were 2 conditions for a diagnosis of GERD: (1) a total score of 4 or higher on the 7-item Carlsson-Dent questionnaire [16]; (2) mild symptoms occurring on 2 or more days a week or more severe symptoms occurring at least once a week [15, 18].

Other items included in the questionnaire included consumption of alcoholic drinks, smoking, use of non steroidal anti inflammatory drugs (NSAID), consumption of coffee and consumption of kolanuts. The statistical program SPPS Version 12 was used in the analysis of results and the results were expressed as means, standard deviation, and proportions. Where appropriate, proportions were compared using Chi-square test and a P value of less than 0.05 was considered significant. Strength of associations was also expressed as relative risk and odds ratio.

Four hundred and ten (410) medical students completed the questionnaire. These were made up of 240 males (58.7%) and 170 females (41.5%). Their ages ranged from 19 years to 50 years (mean = 25.3 ± 3.5 years). The body mass index (BMI) of the students ranged between 17 and 55.12 (mean = 24.11 ± 4.50). One hundred and eighty students (26.34%) satisfied the criteria for diagnosis of GERD, i.e. score of 4 and above in the Carlsson-Dent questionnaire plus symptoms of significant severity [15, 18]. These were made up of 54 males (50%) and 54 females (50%). The difference between the proportion of male students with GERD and the proportion of female students with GERD was not statistically significant (P= 0.111). The remaining 302 students (73.66%) did not satisfy the criteria for GERD.

A test of correlation was carried out between BMI and GERD and there was no correlation (γ= 0.00471, P = 0.9252). Similarly, a test of correlation was carried out between age of the students and GERD and there was no correlation (γ= -0.01052, P = 0.8428). Smoking was recorded in 8 of the students who had GERD and in 18 of those who did not have GERD. The difference between the proportions was not statistically significant (P = 0.6203, relative risk = 1.168, odds ratio = 1.243). Alcohol consumption was noted in 48 students with GERD and in 120 students without GERD. The difference between the proportions was not statistically significant (P = 0.5834, relative risk = 1.085, odds ratio = 1.119). Use of non-steroidal anti-inflammatory drugs (NSAID) was noted in 40 GERD students and in 92 students without GERD. The difference between the proportions was also statistically not significant (P = 0.3743, relative risk = 1.15, odds ratio = 1.216). Use of coffee was noted in 59 students with GERD and 75 students without GERD. The proportion of GERD students who consumed coffee was therefore more than the non-GERD students and the difference was statistically significant (P = 0.0001, relative risk = 1.672, odds ratio = 2.2). Use of kolanut was noted in 48 GERD students and in 68 students without GERD. The proportion of GERD students who consumed kolanut was higher than that of non-GERD students and the difference was statistically significant (P = 0.0012, relative risk = 1.59, odds ratio = 2.015). Table 1 illustrates the relationship between some of the putative risk factors and GERD.

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Table 1. Relationship between GERD and some putative risk factors

There is general agreement among researchers that the prevalence of GERD varies in different parts of the world. A common misperception is that GERD and its complications are rare in Africa [8, 9]. A prevalence of 26.34% among Nigerian medical students shown in this study suggests that GERD is actually common and not rare as previously thought.

The medical students who participated in the study had a mean age of 25.3 ± 3.5 years. Age did not correlate with the presence of GERD symptoms. This is different from the experience of some other researchers on this subject who documented a rising incidence of GERD with age [19]. The reason for this may be the fact that most of the students were in their third and fourth decades of life. A similar study in a more heterogeneous population with broader range of categories of age will most likely give a higher prevalence and the effect of age will be more evident.

Previous studies showed that male gender is a risk factor for erosive esophagitis; whereas females are more likely to be associated with non-erosive reflux disease (NERD) [20, 21]. In this study the prevalence of GERD in male medical students was not different from that of female students. However, it is not possible to predict whether esophageal mucosal lesions would have differed in the two groups because the study was purely questionnaire-based, no endoscopy was done.

BMI did not affect the prevalence of GERD in the students. The relationship between BMI and symptoms of GERD has remained unresolved [22-24]. The effect of BMI on GERD may have come out better if the study population had included older persons who are likely to have higher BMI.

Smoking, alcohol and NSAID use did not affect the prevalence of GERD in this study. Previous studies gave conflicting reports on the effect of smoking [25, 26]. The role of NSAID use in the etiopathogenesis of GERD is equally controversial [27, 28]. However the use of caffeine containing beverage namely coffee and kolanut was clearly more prevalent among the students who had GERD compared to those without GERD (P = 0.0001, relative risk = 1.672, odds ratio = 2.2 for coffee; and P = 0.0012, relative risk = 1.59, odds ratio = 2.015 for kolanut). Coffee drinking is not very common among the general population in Nigeria but may be prevalent among students who drink this beverage to keep awake in order to read especially during examinations. Kolanut has the same effect and is even cheaper. This nut is widely grown in the South Western part of Nigeria but extensively consumed in the Northern and South Eastern parts of the country. GERD may be prevalent in those kola-eating areas. Larger population-based studies are needed to further elucidate this view.

The use of antibiotics for the eradication of Helicobacter pylori (H. pylori) related gastroduodenal disorders became widespread in Nigeria about 15 years ago with the result that many dyspeptic patients are rightly or wrongly placed on this treatment. Drugs for the eradication of H. pylori are administered indiscriminately because there are no guidelines for the use of these drugs and even where the guidelines exist; they are not followed properly because of constraints of poor laboratory support. It is possible that such widespread use of drugs for H. pylori eradication may be attended by a rise in the prevalence of GERD and its complications [29-31]. This thinking needs to be further elucidated by research.

A questionnaire-based study such as this is not without limitations. The Carlsson-Dent questionnaire deals mainly with the major esophageal syndromes of GERD. The atypical features such as chest pain, epigastric pain, laryngitis, chronic cough and asthmatic attacks are not included. The result is that the prevalence determined in this study may be less than what actually obtains. Another limitation is the fact that symptom analysis was not compared with any confirmatory test for GERD. However, it is difficult nowadays to talk about a gold standard for the diagnosis of GERD.

Endoscopy has relatively low sensitivity as the absence of visible mucosal breaks is reported in 55% to 81% of patients presenting with reflux symptoms in primary care [32]. Ambulatory 24 hour pH monitoring is the most widely used test to establish the presence of excessive GERD, and to correlate symptoms temporally with reflux. This test is invasive, inconvenient and costly. Also there exists no absolute threshold value that reliably identifies GERD patients. Investigators evaluating the sensitivity of pH monitoring report obtaining normal esophageal acid exposure in 25% of patients with reflux esophagitis and about 30% of patients with non-erosive reflux disease [33-35].

In conclusion, GERD may not be rare in Africans as previously thought. The prevalence in Nigerian medical students is high and this may be related to the consumption of caffeine-containing substances namely coffee and kolanut consumed commonly by students in their bid to exploit the cerebral stimulant effect of these substances during examinations when they need to stay awake and read. There is a need for more population-based studies on GERD in Nigeria.

Acknowledgements

The author declares no conflicts of interest related to this article.

1. Kennedy T, Jones R. The prevalence of gastro-oesophageal reflux symptoms in a UK population and the consultation behaviour of patients with these symptoms. Aliment Pharmacol Ther. 2000;14(12):1589-1594.
   pubmed doi
2. Locke GR 3rd, Talley NJ, Fett SL, Zinsmeister AR, Melton LJ 3rd. Prevalence and clinical spectrum of gastroesophageal reflux: a population-based study in Olmsted County, Minnesota. Gastroenterology. 1997;112(5):1448-1456.
   pubmed doi
3. Shaw MJ, Talley NJ, Beebe TJ, Rockwood T, Carlsson R, Adlis S, Fendrick AM, et al. Initial validation of a diagnostic questionnaire for gastroesophageal reflux disease. Am J Gastroenterol. 2001;96(1):52-57.
   pubmed doi
4. Chen M, Xiong L, Chen H, Xu A, He L, Hu P. Prevalence, risk factors and impact of gastroesophageal reflux disease symptoms: a population-based study in South China. Scand J Gastroenterol. 2005;40(7):759-767.
   pubmed doi
5. Wahlqvist P. Symptoms of gastroesophageal reflux disease, perceived productivity, and health-related quality of life. Am J Gastroenterol. 2001;96(8 Suppl):S57-61.
   pubmed doi
6. Sandler RS, Everhart JE, Donowitz M, Adams E, Cronin K, Goodman C, Gemmen E, et al. The burden of selected digestive diseases in the United States. Gastroenterology. 2002;122(5):1500-1511.
   pubmed doi
7. Lagergren J, Bergstrom R, Lindgren A, Nyren O. Symptomatic gastroesophageal reflux as a risk factor for esophageal adenocarcinoma. N Engl J Med. 1999;340(11):825-831.
   pubmed doi
8. Sonnenberg A, El-Serag HB. Clinical epidemiology and natural history of gastroesophageal reflux disease. Yale J Biol Med. 1999;72(2-3):81-92.
   pubmed
9. Segal I. The gastro-oesophageal reflux disease complex in sub-Saharan Africa. Eur J Cancer Prev. 2001;10(3):209-212.
   pubmed doi
10. Ndububa DA, Agbakwuru AE, Adebayo RA, Olasode BJ, Olaomi OO, Adeosun OA, Arigbabu AO. Upper gastrointestinal findings and incidence of Helicobacter pylori infection among Nigerian patients with dyspepsia. West Afr J Med. 2001;20(2):140-145.
    pubmed
11. Picardo Neri GA, Nwokediuko SC. Correlation of upper gastrointestinal findings with Helicobacter pylori infection at the University of Nigeria Teaching Hospital, Enugu. Journal of College of Medicine. 1999;4:4-7.
12. Malu AO, Wali SS, Kazmi R, Macauley D, Fakunle YM. Upper gastrointestinal endoscopy in Zaria, northern Nigeria. West Afr J Med. 1990;9(4):279-284.
    pubmed
13. Danbauchi SS, Keshinro IB, Abdu-Gusau K. Fifteen years of upper gastrointestinal endoscopy in Zaria (1978 - 1993). Afr J Med Med Sci. 1999;28(1-2):87-90.
    pubmed
14. Klauser AG, Schindlbeck NE, Muller-Lissner SA. Symptoms in gastro-oesophageal reflux disease. Lancet. 1990;335(8683):205-208.
    pubmed doi
15. Vakil N, van Zanten SV, Kahrilas P, Dent J, Jones R. The Montreal definition and classification of gastroesophageal reflux disease: a global evidence-based consensus. Am J Gastroenterol. 2006;101(8):1900-1920, quiz 1943.
    pubmed
16. Carlsson R, Dent J, Bolling-Sternevald E, Johnsson F, Junghard O, Lauritsen K, Riley S, et al. The usefulness of a structured questionnaire in the assessment of symptomatic gastroesophageal reflux disease. Scand J Gastroenterol. 1998;33(10):1023-1029.
    pubmed doi
17. Wong WM, Lam KF, Lai KC, Hui WM, Hu WH, Lam CL, Wong NY, et al. A validated symptoms questionnaire (Chinese GERDQ) for the diagnosis of gastro-oesophageal reflux disease in the Chinese population. Aliment Pharmacol Ther. 2003;17(11):1407-1413.
    pubmed doi
18. Wiklund I, Carlsson J, Vakil N. Gastroesophageal reflux symptoms and well-being in a random sample of the general population of a Swedish community. Am J Gastroenterol. 2006;101(1):18-28.
    pubmed doi
19. Du J, Liu J, Zhang H, Yu CH, Li YM. Risk factors for gastroesophageal reflux disease, reflux esophagitis and non-erosive reflux disease among Chinese patients undergoing upper gastrointestinal endoscopic examination. World J Gastroenterol. 2007;13(45):6009-6015.
    pubmed doi
20. Lee YC, Wang HP, Chiu HM, Liao SC, Huang SP, Lai YP, Wu MS, et al. Comparative analysis between psychological and endoscopic profiles in patients with gastroesophageal reflux disease: a prospective study based on screening endoscopy. J Gastroenterol Hepatol. 2006;21(5):798-804.
    pubmed doi
21. Fujiwara Y, Higuchi K, Shiba M, Yamamori K, Watanabe Y, Sasaki E, Tominaga K, et al. Differences in clinical characteristics between patients with endoscopy-negative reflux disease and erosive esophagitis in Japan. Am J Gastroenterol. 2005;100(4):754-758.
    pubmed doi
22. Jacobson BC, Somers SC, Fuchs CS, Kelly CP, Camargo CA Jr. Body-mass index and symptoms of gastroesophageal reflux in women. N Engl J Med. 2006;354(22):2340-2348.
    pubmed doi
23. Lagergren J, Bergstrom R, Nyren O. No relation between body mass and gastro-oesophageal reflux symptoms in a Swedish population based study. Gut. 2000;47(1):26-29.
    pubmed doi
24. Murray L, Johnston B, Lane A, Harvey I, Donovan J, Nair P, Harvey R. Relationship between body mass and gastro-oesophageal reflux symptoms: The Bristol Helicobacter Project. Int J Epidemiol. 2003;32(4):645-650.
    pubmed doi
25. Nilsson M, Johnsen R, Ye W, Hveem K, Lagergren J. Lifestyle related risk factors in the aetiology of gastro-oesophageal reflux. Gut. 2004;53(12):1730-1735.
    pubmed doi
26. Nocon M, Labenz J, Willich SN. Lifestyle factors and symptoms of gastro-oesophageal reflux — a population-based study. Aliment Pharmacol Ther. 2006;23(1):169-174.
    pubmed doi
27. el-Serag HB, Sonnenberg A. Associations between different forms of gastro-oesophageal reflux disease. Gut. 1997;41(5):594-599.
    pubmed
28. Kim SL, Hunter JG, Wo JM, Davis LP, Waring JP. NSAIDs, aspirin, and esophageal strictures: are over-the-counter medications harmful to the esophagus?. J Clin Gastroenterol. 1999;29(1):32-34.
    pubmed doi
29. Labenz J, Tillenburg B, Peitz U, Borsch G, Idstrom JP, Verdu E, Stolte M, et al. Efficacy of omeprazole one year after cure of Helicobacter pylori infection in duodenal ulcer patients. Am J Gastroenterol. 1997;92(4):576-581.
    pubmed
30. el-Serag HB, Sonnenberg A. Opposing time trends of peptic ulcer and reflux disease. Gut. 1998;43(3):327-333.
    pubmed
31. Sasaki A, Haruma K, Manabe N, Tanaka S, Yoshihara M, Chayama K. Long-term observation of reflux oesophagitis developing after Helicobacter pylori eradication therapy. Aliment Pharmacol Ther. 2003;17(12):1529-1534.
    pubmed doi
32. Achem SR. Endoscopy-negative gastroesophageal reflux disease. The hypersensitive esophagus. Gastroenterol Clin North Am. 1999;28(4):893-904, vii.
    pubmed
33. Johnsson F, Joelsson B. Reproducibility of ambulatory oesophageal pH monitoring. Gut. 1988;29(7):886-889.
    pubmed doi
34. Wiener GJ, Morgan TM, Copper JB, Wu WC, Castell DO, Sinclair JW, Richter JE. Ambulatory 24-hour esophageal pH monitoring. Reproducibility and variability of pH parameters. Dig Dis Sci. 1988;33(9):1127-1133.
    pubmed doi
35. Younes Z, Johnson DA. Diagnostic evaluation in gastroesophageal reflux disease. Gastroenterol Clin North Am. 1999;28(4):809-830, v.
    pubmed

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