title: Normal values of 24-hour ambulatory esophageal impedance-pH monitoring in a rural South African cohort of healthy participants.
abstract: There are no data on 24-hour multichannel intraluminal impedance and pH monitoring in African populations. The purpose of this study was to provide the normal values of esophageal impedance and pH monitoring in a rural African populations. South African healthy rural participants were recruited and underwent 24 hours of esophageal impedance and pH monitoring. The median and the 95th percentiles of the total reflux episodes were 49 and 97, respectively, of which the corresponding number of acidic, weakly acidic, and weakly alkaline reflux were 15 and 55, 17 and 51, and 8 and 36, respectively. The compositions of the total reflux were 5 and 21 for liquid, 27 and 72 for mixed, and 10 and 39 for gas reflux, respectively. The median bolus clearance was 18 seconds and the median bolus exposure was 14 minutes/24 hours. The proximal extent was 6%. The 95th percent time of esophageal exposure to acid was 8.6 in 24 hours. Female and overweight participants were associated with an increased number of reflux events. There were more reflux episodes, and of which, more were weakly alkaline compared with previous similar studies. The findings provide reference values of gastroesophageal reflux for a South African rural population.
authors.affiliation: Department of Physiology, Faculty of Health Sciences, Walter Sisulu University, Mthatha, South Africa.
authors.forename: E J
authors.initials: EJ
authors.lastname: Ndebia
authors.affiliation: Department of Physiology, Faculty of Health Sciences, Walter Sisulu University, Mthatha, South Africa.
authors.forename: A M
authors.initials: AM
authors.lastname: Sammon
authors.affiliation: Department of Physiology, Faculty of Health Sciences, Walter Sisulu University, Mthatha, South Africa.
authors.forename: E
authors.initials: E
authors.lastname: Umapathy
authors.affiliation: Department of Physiology, Faculty of Health Sciences, Walter Sisulu University, Mthatha, South Africa.
authors.forename: J E
authors.initials: JE
authors.lastname: Iputo
mesh_terms: D000328:Adult; D017097:Electric Impedance; D050782:Esophageal pH Monitoring / Q000379:methods*; D005260:Female; D005745:Gastric Acidity Determination; D005764:Gastroesophageal Reflux / Q000175:diagnosis / Q000453:epidemiology; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012424:Rural Population; D013019:South Africa / Q000453:epidemiology
keywords: South Africa; esophagus; reference value; reflux