P142 Developing a novel model of gastro-oesophageal function in health: first data from healthy controls

Introduction

Gastro-oesophageal function in medically refractory gastroesophageal reflux disease (GORD) is poorly understood. Therefore, we developed a novel multi-model study in attempt to further understand these complex interactions through the utilisation of combined physiology techniques, including high resolution manometry (HRM), 24-hour pH-impedance (ZpH), C13 gastric emptying breath tests (GEBT), and body surface gastric mapping (BSGM).

Methods

An initial cohort of 10 healthy controls were screened and recruited using the Gastroesophageal Reflux Disease Questionnaire (GERDQ). Participants also completed ROME IV, PAGI-QOL, PAGI-SYM and real time study symptom questionnaires. BSGM was performed after a six hour fast with a standard test protocol of 30 minutes to evaluate the BSGM baseline. HRM was then performed with 10 supine 5 ml swallows to classify oesophageal motility. Then a 233 kcal porridge meal labelled with C13 sodium acetate was given to the participant to consume over a 10 minute period. During the postprandial period, GEBT, ZpH, and BSGM were recorded. After 4 hours, GEBT and BSGM were concluded, while ZpH testing was continued until 24 hours had passed. Data was analysed using standard procedures and compared with established reference intervals.

Results

Of the 10 healthy controls (6 males, median age 27.5 years [23–57 years]), none met ROME IV criteria and the mean score was 4.91 and 0.08 for PAGI-QOL and PAGI-SYM, respectively. No participants had pathological GORD (>6% oesophageal acid exposure time [AET]) with a median AET of 0.8% (0–4.5%) and median reflux episodes of 25 (2–52). 4 participants had at least 1 laryngopharyngeal reflux (LPR) event (median 0.5 [0–7]). No participants had disorders of peristalsis bar 2 meeting criteria for ineffective oesophageal motility. 3 participants had delayed gastric emptying (median T lag 34.5 minutes [6–56 minutes] and median T ½ 68.5 minutes [52–99 minutes]). 3 participants had abnormal BSGM (2 abnormal Gastric Alimetry Rhythm Index and 1 abnormal gastric frequency). Abnormal BSGM was not related to ZpH or GEBT, but on HRM, all 3 participants with an abnormal BSGM had a hiatus hernia (mean 1.8 ± 0.71 vs 0.4 ± 0.67 cm, p = 0.023).

Discussion

These data show that it is feasible to use a complex combination of techniques to assess gastro-oesophageal function at a level of detail not previously possible. These data also highlight the importance of establishing comprehensive normative data prior to embarking on detailed clinical studies and the expansion of this healthy cohort is warranted.