{
  "abstract": "Introduction The mechanism of increased gastro-oesophageal reflux (GOR) in people with cystic fibrosis (pwCF) is unclear but represents significant symptom burden. We investigated the biomechanics of GOR in CF by comparing oesophageal motility, measures of oesophago-gastric junction (OGJ) tone and gastro-oesophageal pressure gradients (GOPG) using high-resolution manometry (HRM) in pwCF with and non-CF controlsMethods Two groups of GOR patients with reflux symptoms were prospectively recruited – PwCF and non-CF controls (without lung disease). Both groups underwent HRM with additional manoeuvres: cough, maximal inhalation and exhalation. HRM motility patterns for both pwCF and non-CF controls were compared using Chicago Classification v.4.0 (CCv4.0). OGJ tone was analysed using novel metrics of OGJ integrity: oesophageal-gastric junction mean pressure (OGJ-MP: reflective of all pressures in the OGJ) and oesophageal-gastric junction contractile index (OGJ-CI: reflecting the contribution of the crural diaphragm). Augmentation of OGJ tone and GOPG during cough and maximal inhalation and exhalation was also evaluated. We compared all the evaluated metrics between the two groups statistically using Welch T Tests and Fisher Exact Tests.Results HRM data with additional manoeuvres from 70 patients (35 pwCF, and 35 non-CF controls) were evaluated. PwCF were significantly more likely to exhibit a CCv4.0 defined oesophageal motility disorder (19/35, 55% vs. 6/35, 17%, p<0.0001). Among the CF group, 43% demonstrated Ineffective Oesophageal Motility (CCv4.0).PwCF had a lower GOPG (13.5mmHg vs. 23.5mmHg, p<0.0001) during maximal inhalation alongside concurrent lower mean gastric pressures (6.0mmHg vs. 15.7mmHg, p<0.0001) and a lower mean BMI (p<0.0001). At rest, pwCF had a higher LOS pressure (23.1mmHg vs 17.3mmHg, p=0.03), and a numerically higher OGJ-MP (22.9mmHg vs. 18.2mmHg, p=0.07). There was no difference in the OGJ-CI at rest between the groups (p=0.3).During cough manoeuvres, gastric pressure was more likely to exceed OGJ pressure (21/35, 60% vs. 2/35, 6%, p=0.002) and oesophageal pressure (18/35, 51% vs. 3/35, 9%, p<0.0001) in pwCF. The pressure augmentation at the OGJ from maximal exhalation to maximal inhalation was lower in pwCF (pressure increase of 6.3mmHg vs. 50.2mmHg, p<0.0001).Conclusions This study demonstrates that changes in gastro-oesophageal pressure gradients affecting OGJ tone may contribute to the predisposition of pwCF to GOR. These findings may have implications for the treatment of reflux in pwCF and aid in limiting reflux-related respiratory exacerbations. Future studies could correlate GOPG with 24-hour pH-impedance monitoring outcomes and investigate whether similar mechanisms are present in other chronic pulmonary diseases.",
  "authors": [
    {
      "affiliations": [
        "Manchester University NHS Foundation Trust, Manchester, United Kingdom"
      ],
      "name": "Lottie Keyse"
    },
    {
      "affiliations": [
        "Manchester University NHS Foundation Trust, Manchester, United Kingdom"
      ],
      "name": "Sharon Archbold"
    },
    {
      "affiliations": [
        "Manchester University NHS Foundation Trust, Manchester, United Kingdom"
      ],
      "name": "Charlotte Pitcher"
    },
    {
      "affiliations": [
        "Manchester University NHS Foundation Trust, Manchester, United Kingdom"
      ],
      "name": "Jaclyn Smith"
    },
    {
      "affiliations": [
        "Manchester University NHS Foundation Trust, Manchester, United Kingdom"
      ],
      "name": "Andrew Jones"
    },
    {
      "affiliations": [
        "Manchester University NHS Foundation Trust, Manchester, United Kingdom"
      ],
      "name": "Robert Lord"
    },
    {
      "affiliations": [
        "Manchester University NHS Foundation Trust, Manchester, United Kingdom"
      ],
      "name": "Dipesh Vasant"
    }
  ],
  "title": "P399 Could manometric differences in oesophago-gastric junction tone and gastro-oesophageal pressure gradients contribute to reflux in people with cystic fibrosis?",
  "uid": "3a15a58d-799c-5035-97cd-c9df46324484"
}