Efficacy and tolerability of hydrogen carbonate-rich water for heartburn.

AIM To investigate the efficacy and safety of mineral water with a high content of hydrogen carbonate in patients with heartburn. METHODS This open, single-center, single-arm clinical pilot study enrolled 50 patients, 18-64 years old, who had been suffering from heartburn at least twice a week for at least 3 mo before entering the study. Pharmacological treatment of heartburn was not permitted, and patients with severe organic diseases were excluded. After a run-in period of one week, the participants received 1.5 L of the test water for the following 6 wk; 300 mL with meals t.i.d., the remainder to be drunk throughout the day. During the trial, there were five visits at the study center (screening, baseline, two interim visits and the final visit). The efficacy endpoints included incidence and duration of heartburn episodes per week by patient's self-assessment (heartburn diary) as well as changes in symptom severity as per symptom specific questionnaires [Reflux Disease Questionnaire (RDQ); Quality of Life in Reflux and Dyspepsia (QOLRAD); Gastrointestinal Quality of Life Index] and overall health-related quality of life per SF-12 (12-question short form) at each visit. At the end of the study, patients and investigators independently rated the overall efficacy of the test water on a 4-point Likert scale. Safety was assessed by evaluation of adverse events (AEs), vital signs (heart rate, blood pressure) and laboratory parameters. Changes from initial to final examinations were assessed by the non-parametric Wilcoxon test; categorical variables were compared using the χ(2) test, and for more than 5 categories, by the U-test. RESULTS Twenty-eight participants were men, 22 women. The mean age of the patients in the full analysis set/intention-to treat population (FAS/ITT) was 40.6 years. Forty-two participants completed the study according to the study protocol and formed the per-protocol set (PP population); 48 participants drank the water at least once as requested and were analyzed as ITT population. The occurrence of heartburn was statistically significantly reduced at wk 6 in both the ITT and the PP populations. At wk 6, the mean number of heartburn episodes/week decreased by 5.1 episodes (P < 0.001) and the mean duration of heartburn symptoms by 19 min (ITT) (P = 0.002). The frequency of heartburn symptoms was reduced in 89.6% of the patients (P < 0.001), and the duration of symptoms in 79.2% of patients (ITT) (P < 0.001). All dimensions of the RDQ (heartburn, regurgitation, gastro-esophageal reflux disease symptoms, dyspepsia) showed a significant improvement at 6 wk. Likewise, disease-specific quality of life improved significantly (QOLRAD, GIQLI). Overall, 89.4% of patients rated the efficacy of the test water as "good" or "very good", as did the investigators for 91.5% of the patients. There were no serious AEs. After 6 wk, systolic and diastolic blood pressure values decreased slightly but significantly [-3.5 and -3.0 mmHg, respectively (P = 0.008 and P = 0,002)]. Ninety-six percent of patients and investigators for the same percentage of patients rated the tolerability of the water as "good" or "very good". CONCLUSION The data demonstrate effectiveness of a hydrogen carbonate-rich mineral water in alleviating heartburn frequency and severity, thereby improving quality of life. The water has excellent tolerability.