Risk Factors for Nighttime Gastroesophageal Reflux Disease

Implications of Findings

Using bivariate analyses of the demographic parameters evaluated, only male sex and having a college education were found to decrease the risk of reporting heartburn during sleep. However, although male sex became a nonsignificant variable in the multivariate models, having a college education remained significant after adding multiple confounding factors. The protective effect of having a college education in relation to heartburn during sleep is difficult to explain, but may be related to the level of understanding of surveys. Additionally, having a college education may be a surrogate marker for differences in lifestyle and diet, greater adherence to health-related activities, and increased knowledge about precipitating factors for GERD.

Several studies have reported high prevalence of GERD symptoms as well as increased esophageal acid exposure with greater BMI.[15,16] The current study was the first to demonstrate an association between increased BMI and heartburn during sleep. The mechanism by which increased BMI contributes to GERD remains an area of intense controversy.

Of all social habits that have been suggested to promote gastroesophageal reflux, only carbonated soft drink consumption was highly associated with reports of heartburn during sleep. Other investigators have found that tobacco smoking and alcohol use were not strongly associated with gastroesophageal reflux symptoms.[17] However, none of the studies assessed the intake of carbonated soft drinks as an important risk factor for GERD symptoms in general or specifically for heartburn during sleep. Carbonated soft drinks are likely to cause heartburn because of their acidic content and the carbonation process.

Factors associated with sleep and sleep-disordered breathing were strongly associated with reports of heartburn during sleep. Insomnia had the highest calculated odds ratio (2.05) and may be the result, rather than the cause, of heartburn during sleep. Of the 3 types of medications (antidepressants, calcium-channel blockers, and benzodiazepines) known to precipitate gastroesophageal reflux due to their effect on the lower esophageal sphincter (LES) resting pressure and/or esophageal motility, only the use of benzodiazepines was significantly associated with heartburn during sleep.[4] Benzodiazepines have been demonstrated both in animal models and in humans to decrease the basal LES pressure and to increase the number of gastroesophageal reflux events.[18] However, it is not clear why benzodiazepines show a stronger relationship to heartburn during sleep as compared with other types of medications that are known to affect the resting LES pressure. Several benzodiazepines are commonly used as hypnotics, and thus one potential explanation, albeit incomplete, is that there is greater consumption of these compounds at bedtime as sleeping pills.

Hypertension is likely to be a risk factor for heartburn during sleep due to factors other than hypertension per se. Anti-hypertensive medications, comorbid factors, diet, and body habitus may all contribute to the occurrence of nocturnal heartburn (or only some of these factors may have a role).[4]

Asthma may cause gastroesophageal reflux by increasing the pressure gradient between the thorax and the abdomen.[19] Alternatively, gastroesophageal reflux may result in asthma by small aspirations of acid or through the vagovagal reflux arc.[20,21] Adult asthmatics are more prone to develop nocturnal bronchoconstriction due to gastroesophageal reflux.[21] It is possible that these events are more associated with heartburn during sleep.

Source: Medscape Education