Melatonin for the treatment of gastroesophageal reflux disease; protocol for a systematic review and meta-analysis

Background: Melatonin generated in the gastrointestinal tract has mucosal protective effect with inhibiting gastric acid secretion, while increasing gastrin release, which in turn stimulates the contractility of lower esophageal sphincter. Gastroesophageal reflux disease (GERD) is also known to have association with sleep disturbance. However, melatonin or melatonin receptor agonist has not been included in the treatment of GERD. This study aimed to evaluate the efficacy of melatonin for the treatment of GERD. Methods: We will search the core databases [MEDLINE (through PubMed), the Cochrane Library, and Embase] from their inception to December 2018 by 2 independent evaluators. The P.I.C.O. is as follows; Patients: who have GERD, Intervention: melatonin or melatonin receptor agonist treatment, Comparison: patients without melatonin or melatonin receptor agonist treatment, Outcome: clinical indices (or crude number or proportion of improvement) for the evaluation of symptomatic improvement which enable comparison of efficacy between patients with melatonin or melatonin receptor agonist and the control group. All types of study design will be sought with full-text will be included. The risk of bias will be assessed using the ROBINS-I tool. Descriptive data synthesis is planned and quantitative synthesis will be used if the included studies are sufficiently homogenous. Publication bias will be assessed with quantitative analyses if more than 10 articles are enrolled. Results: The results will provide evidence for the efficacy of melatonin or melatonin receptor agonist for the treatment of GERD. Conclusion: This study will provide evidence of melatonin or melatonin receptor agonist treatment for GERD.