Introduction Central obesity promotes gastroesophageal reflux and this may be related to elevated intra-abdominal pressure. We have investigated the effect of increasing abdominal pressure by waist belt on reflux in patients with reflux disease.

Method Fourteen male patients who had evidence of at least Los Angeles grade B oesophagitis were studied with and without waist belt constriction. Combined high resolution pHmetry (12 sensors at 11 mm intervals) and high resolution manometry (36 sensors at 7.5 mm intervals) was performed for 20 min fasted and 90 min following a standardised meal. The position of the squamocolumnar junction (SCJ), marked with two endoscopically placed radio-opaque clips, was visualised radiologically relative to the probes. All continuous data are expressed as medians. Comparison of variables between related groups was made using the Wilcoxon Signed Rank test. For correlations between two continuous variables, the Spearman Rho bivariate correlations were used.

Results Without the belt and fasted, intragastric pressure correlated with waist circumference (r=0.68, p=0.008) with a pressure range of 15 mmHg. The waist belt increased intragastric pressure by a median of 6.9 mmHg during fasting (p=0.002) and by 9.0 mmHg after the meal (p=0.001) with the latter greater than former (p<0.01). Gastroesophageal acid reflux at each of the 5 pH sensors extending 5.5 cm proximal to the peak LES pressure point was increased by approximately 8-fold by the belt in the postprandial period. At 4.4 cm proximal to the peak LES pressure point, the percentage time pH <4 was 4.7% with versus 0.5% without the belt (p=0.002). At 5.5 cm, the percentage time pH <4 was 2.5% with versus 0.2% without the belt (p=0.038). The pH transition point was precisely at the level of the SCJ without the belt, and 1.17 cm proximal to SCJ with the waist belt (p=0.016). Following the meal, the mean number of reflux events with the belt was 4, versus 2 without (p=0.008). TLESRs were not increased by the belt but those associated with reflux were increased (2 versus 3.5, p=0.04). The most marked effect of the belt was impaired oesophageal clearance of refluxed acid with median values of 23.0 versus 81.1 s (p=0.008). The pattern of impaired clearance was that of rapid re-reflux after peristaltic clearance.

Conclusion Waist belt compression causes marked aggravation of acid reflux following a meal in patients with reflux disease. The intragastric pressure rise inducing this effect is well within the range associated with differing waist circumference and likely to be relevant to the association between central obesity and reflux disease. The findings also support avoidance of tight waist belt in reflux patients after a meal.

Disclosure of Interest None Declared