Commentary: The relation of obesity, reflux and its implications

A Dixon and J Jankowski

The Digestive Diseases Centre, Leicester University Hospitals, Leicester.

The relationship between gastro-oesophageal reflux disease (GORD) and obesity seems at first thought an obvious one. Indeed one of the foremost treatment strategies adopted is advice on lifestyle. Patients are usually advised to lose weight if they are obese, drink less alcohol and caffeine, and stop smoking. However, the evidence behind these instructions appears to be flawed when looked at in more detail. This paper1 aids in understanding the link between obesity and GORD.

The prevalence of GORD and obesity both appear to be increasing throughout the Western world. Oesophagitis can occur at any age but is more common in men than women, at a ratio of 2:1.2 The natural history is that of a chronic relapsing condition.3 The causation between the two is still not clearly known but factors such as increased sensitivity of the oesophagus to acid, increased prevalence of hiatus hernia, increased intra abdominal pressure, and vagal abnormalities in obese patients may cause higher bile and pancreatic enzyme output, so making the resulting refluxate more toxic.4 In one paper there was a strong correlation between obese females and GORD, and it appeared compounded by the use of oestrogen replacement therapies. It was suggested that there is an association between increased oestrogen activity and the symptoms of GORD in obese females.5 In the treatment of GORD the medications used seldom vary in dose despite the varying size of patients. Body composition affects the pharmacokinetics of drugs taken in the treatment of GORD. There are few data about the efficacy of drug treatments in obese patients but poor absorption or a larger distribution of body mass may lead to the medications being less effective in their action. Less effective treatment can lead to further complications in the long term.

Obesity is rapidly becoming a major health issue in terms of its burden on health and health planning. We know obesity is increasing in prevalence and its relationship to GORD is shown in the Murray et al. paper.1 Studies from the US have shown that 20% of the population had a body mass index of >30 kg/m2; this figure has almost doubled from that of 20 years ago.6 The implications for health are highlighted not only with regards to GORD but also diabetes, hypertension, hyperlipidaemia, and heart disease, as well as sleep apnoea and liver disease.

Inheritance of GORD has been explored in twin studies and these certainly show a degree of genetic determination in susceptibility to GORD. One study showed an increased concordance for reflux in monozygotic compared to dizygotic twins and hereditability accounted for 31% of the liability to reflux disease within the study population. The study also showed the concordance for reflux was not caused by inherited obesity.7

One of the important things arising from the increasing prevalence of obesity and GORD is the planning of health services and what may lie ahead as a sequelae. The problems associated with obesity as described earlier will have many implications for the delivery of services throughout the majority of medical specialities. Within the gastroenterological specialty the impact is going to come in the form of increased problems associated with reflux disease. We already know that there is an increasing number of patients with reflux-associated diseases such as Barrett’s oesophagus and adenocarcinoma of the oesophagus. This may be linked to obesity as a causative factor, but the development of oesophageal adenocarcinoma may also be linked to obesity and diet independently8 of reflux disease. Having said this, the effect of obesity and reflux together may multiply the risk of developing problems.9

This paper from the Bristol Helicobacter Project sets out nicely the relationship between GORD and increased body mass. There is belief that obesity is related to GORD, but some studies in the past show no or weak associations and some run contrary to the hypothesis.10 The study, a randomized controlled trial of eradication of Helicobacter pylori, looks at a large number of patients aged 20–59 years. The study measured reflux in terms of frequency and severity of the patient’s symptoms only and not necessarily from actual true episodes as would be measured from pH studies. The definition of obesity in the paper is a very valid one—body mass index (BMI) >25 kg/m2—but one must bear in mind that this is merely a ratio of the patient’s weight to height and does not necessarily define the patient’s body fat content. With a high proportion of the population having a BMI >25 kg/m2 it may imply that in order to gain benefit in relation to GORD one may need to have a relatively low BMI. The paper highlights that being above normal weight substantially increases the likelihood of suffering heartburn and acid regurgitation. The authors also state that an obese person is almost three times more likely to experience symptoms than a person of normal weight. It gives further evidence that a reduction in weight may therefore improve symptoms and patients’ quality of life, however, further evaluation of these patients needs to be carried out to see if they, as a group, have improvements of symptoms with weight loss—i.e. those obese patients with GORD symptoms need to be re-assessed once weight loss has been sustained in order to see that their symptoms improve. The implications of the paper are great because it highlights the impact on the health of the public at large. The added cost of dealing with an increasingly obese population is vast, and the impact it may have on health services is yet to be evaluated. Further, if the population trend of obesity continues to rise then we will be seeing many more patients with GORD-related symptoms and the unfortunate sequelae of oesophageal adenocarcinoma that may follow.


    References
 Top
 References
 
1 Murray L, Johnston B, Lane A et al. Relationship between body mass and gasto-oesophageal reflux symptoms: The Bristol Helicobacter Project. Int J Epidemiol 2003;32:645–50.[Abstract/Free Full Text]

2 Wienback M, Barnet J. Epidemiology of reflux disease and reflux oesophagitis. Scand J Gastroenterol 1989;24(Suppl.156):7–13.

3 Stoker DL, Williams JG, Leicester RG, Colin-Jones DG. Oesophagitis: a five year review. Gut 1988;29:A1450.

4 Barak N, Ehrenpreis ED, Harrison JR, Sitrin MD. Gastro oesophageal reflux disease in obesity: pathophysiological and therapeutic considerations. Obesity Rev 2002;3:9–15.[CrossRef]

5 Nilsson M, Lundegardh G, Carling L, Ye W, Lagegren J. Body mass and reflux disease: an oestrogen dependant association? Scand J Gastroenterol 2002;37:626–30.[CrossRef][ISI][Medline]

6 O Brien PE, Dixon JB. The extent of the problem of obesity. Am J Surg 2002;184(6B):4S–8S.[CrossRef][ISI][Medline]

7 Cameron AJ, Lagergren J, Henriksson C, Nyren O, Locke RG, Pederson NL. Gastro oesophageal reflux disease in monozygotic and dizygotic twins. Gastroenterology 2002;122:55–59.[ISI][Medline]

8 Brown LM, Swanson CA, Gridley G et al. Adenocarcinoma of the oesophagus: role of obesity and diet. J Natl Cancer Inst 1995;87:104–09.[Abstract]

9 Lagergren J, Bergstom R, Nyren O. Association between body mass and adenocarcinoma of the oesophagus and gastric cardia. Ann Intern Med 1999;130:883–90.[Abstract/Free Full Text]

10 Lagergren J, Bergstom R, Nyren O. No relation between body mass and gastro oesophageal reflux symptoms in a Swedish population based study. Gut 2000;47:26–29.[Abstract/Free Full Text]





This Article
Extract
FREE Full Text (PDF)
Alert me when this article is cited
Alert me if a correction is posted
Services
Email this article to a friend
Similar articles in this journal
Similar articles in ISI Web of Science
Similar articles in PubMed
Alert me to new issues of the journal
Add to My Personal Archive
Download to citation manager
Request Permissions
Google Scholar
Articles by Dixon, A
Articles by Jankowski, J
PubMed
PubMed Citation
Articles by Dixon, A
Articles by Jankowski, J