Gastroesophageal reflux and sleep problems

Abstract: Gastroesophageal reflux disease (GERD) and sleep problems are common health problems in the Western world affecting up to 30% and 33% of the population respectively. GERD is associated with decreased quality of life, medication, increased use of health care facilities and increased risk of esophageal adenocarcinoma. Sleep problems are linked to mental disorders, pain disorders, coronary heart disease, impaired work productivity and increased risks of traffic accidents. These two disorders have been shown to be associated and a bidirectional association has been suggested. The main focus of this thesis is the link between sleep problems and gastroesophageal reflux symptoms (GERS), while also including one study of the related potential association of obstructive sleep apnea and Barrett ?s esophagus. In study I we explored prevalence changes, incidence and spontaneous loss of GERS in a longitudinal population-based setting using the Nord-Trøndelag health study (HUNT). Included in the study were all residents of the county of Nord-Trøndelag, Norway and who reported any degree of GERS in 1995-1997 (n=58,869) and in 2006-2009 (n=44,997). Of these, 29,610 (61%) responded at both time points with an average of 11 year follow-up. Between 1995-1997 and 2006-2009 we found a 30% increase in the prevalence of any GERS, a 24% increase in severe GERS and a 49% increase in the prevalence of at least weekly GERS. The average annual incidence was 3.07% for any GERS and 0.23% for severe GERS, while the annual average spontaneous loss of any GERS were 2.32% and 1.22% respectively. In study II we used a cross-sectional co-twin control design to analyze the association between sleep problems and GERD while controlling for hereditary factors. Included in the study were 8,014 same-sexed twins of at least 65 years of age born 1886-1958 identified from the Swedish Twin Register. There was a dose-dependent association between sleep problems and GERD which remained when only discordant dizygotic twins (one twin has GERD the other not) were included in the analysis but this was not seen for monozygotic twins. The association between sleep problems and GERD does not seem to be confounded by hereditary factors. In study III we explored the association between symptoms of obstructive sleep apnea, GERS and Barrett’s esophagus in a population-based case-control study from Brisbane, Australia. Included in the study were 237 cases of histological confirmed Barrett ?s esophagus and 247 population-controls. No statistically significant association between obstructive sleep apnea symptoms and Barrett ?s esophagus was observed. In study IV we investigated the direction of association between sleep problems and GERS, based on the same two previously describe data collections from HUNT (see study I). We found that the association between sleep problems and GERS seems to be bidirectional, but contrary to what was expected we found a stronger association sleep problems and incident GERS than between GERS and incident sleep problems.