Slight Weight Gain Can Lead to GERD

Summarized by Robert W. Griffith, MD
September 25, 2006

Summary

A study shows that even modest weight gain can cause or aggravate the symptoms of gastroesophageal reflux disease (GERD) in women.

Introduction

In gastroesophageal reflux disease (GERD), stomach acids back up into your esophagus, causing heartburn and acid regurgitation. As many as 60% of people experience GERD at least once a year, and 20-30% of people have an attack as often as once a week. One tends to regard it as a trivial complaint (unless one has it), but in fact it causes millions of doctor visits, loss of time at work, and, in a few patients, esophageal carcinoma.

Obesity or overweight is a recognized cause of GERD, according to clinical studies. But less is known about the effect of relatively small weight changes, even in 'normal-weight' subjects. However, further analysis of data from the Nurses Health Study, which has appeared in the New England Journal of Medicine, throws light on this; here's a summary of the report.

What was done

The Nurses Health Study was started in 1976 when over 20,000 nurses between 30 and 55 were enrolled. Participants receive health-related questionnaires every 2 years. In 2000, a questionnaire about GERD symptoms was sent to 11,000 participants who had reported asthma or chronic obstructive pulmonary disease (COPD), and to 11,000 participants without respiratory problems.

Information was obtained on the frequency, severity, and duration of heartburn and acid reflux, as well as measurements that allowed calculation of the body mass index (BMI) - height and weight.

GERD frequency was categorized as none, less than once a month, about once a month, about once a week, several times a week, or daily; once a week or more was considered "frequent". Severity was classified as mild, moderate, severe, or very severe.

Participants were categorized according to their BMI; less than 20, 20-22.4, 22.5-24.9, 25-27.4, 27.5-29.9, 30-34.9, and 35 or over.

The analyses concentrated on participants with frequent GERD symptoms and those with symptoms of moderate severity. The search was for associations of symptoms with BMI levels, using the odds ratio, using data from women with a BMI of 20-22.4 as the reference, or 'normal weight' population. In addition, BMI changes between 1984 and 1988 (the time points when BMI levels were measured) were examined for possible links to symptoms.

What was found

The likelihood of having moderately severe GDRD symptoms at least weekly is expressed in the table, using a BMI of 20 to 22.4 as normal, i.e. having an odds ratio (likelihood) of 1.0:

BMI	Odds Ratio
Less than 20	0.67
20.0 - 22.4	1.0 (reference, 'normal')
22.5 - 24.9	1.38
25.0 - 27.4	2.20
27.5 - 29.9	2.43
30.0 - 35.0	2.92

It can be seen that there is a straight-line relationship, more or less. The higher a woman's BMI, the higher the likelihood of her having GERD symptoms. For obese women, the chances are almost three times higher. These results were obtained after adjusting for factors that might bias the outcome - age, diet, smoking status, alcohol, and medications taken.

When weight changes were examined, a similar relationship was found. For women with a BMI of 25 or less in 1984, an increase in BMI of 0.5 to 1.5 units (kg/m²) had a likelihood of 1.13 times their previous frequency of symptoms. An increase of 1.5 to 3.5 in BMI had a likelihood of 1.26 times; and when the increase was over 3.5 BMI units the likelihood rose to 2.8 times, or an almost three times greater chance of frequent symptoms. Conversely, women who reduced their BMI values by 3.5 mg/kg² had a 40% reduction in their symptom frequency; lesser decreases in BMI had lesser reductions in frequent symptoms.

What these results mean

The study shows a strong link between BMI and symptoms of GERD in women. This link included all categories of BMI, indicating that the risk of symptoms rises with BMI in both normal weight and overweight women. Furthermore, it shows that weight increase (i.e. BMI increase), or decrease, can affect the frequency of GERD symptoms in a similar fashion.

This information from a large, well-conducted study should encourage GERD sufferers to take the necessary actions to control, and if possible reduce, their weight. Although the study was done in women, there's no reason to believe that similar findings wouldn't be produced in men, although the authors of the report won't comment on this. In fact, Dr Jacobson intends to do a similar study in men. But men could probably start right now with reducing their weight, if they have GERD and aren't actually underweight.

Source

• Body-mass index and symptoms of gastroesophageal reflux in women. BC. Jacobson , SC. Somers, CS. Fuchs,  et al., N Engl J Med, 2006, vol. 354, pp. 2340--2348

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