Secondhand Smoke Linked to Increased Risk of GERD, Peptic Ulcer in Non-Smokers

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A large-scale analysis revealed secondhand smoke (SHS) exposure increased the risk of peptic ulcer disease (PUD) and gastroesophageal reflux disease (GERD) among non-smokers.

Smoking is linked to an increased prevalence of a number of conditions, including reproductive disorders, periodontal disease, cardiovascular disease, osteoporosis, ophthalmologic disorders, gastrointestinal disease and infection. However, research also points to the dangers of secondhand smoke among non-smokers.

“Active smokers are known to be at an increased risk of both GERD and PUD, however the role of passive smoking remains unclear,” a group of investigators from Kaohsiung Medical University, Taiwan, wrote.

Common symptoms of PUD, which affects approximately 8 million people globally, include abdominal pain or fullness and bloating. Risk factors include smoking, tobacco, and increased weight and can cause ulcer bleeding, gastric outlet obstruction and perforation. PUD has also been linked to various social, biological and psychological factors, such as panic disorders, childhood abuse, stress, suicidal thoughts and depression.

Similarly, individuals at an increased risk of developing GERD are tobacco smokers, have excess weight and consume alcohol, in addition to other dietary factors. Complications include esophageal adenocarcinoma, reflux esophagitis and reflux stricture. Due to the increased prevalence and potentially serious complications, a more comprehensive understanding of risk factors is crucial.

The population-based study assessed whether SHS exposure could increase the odds of developing these gastrointestinal conditions using data from a cohort of 88,297 never-smokers in the Taiwan Biobank. Participants were divided into groups based on SHS exposure frequency: “no exposure,” “<1 hour per week,” and “≥1 hour per week.” Investigators then compared those with SHS exposure to those without.

Of the 121,364 subjects enrolled in the database, 33,067 were smokers and therefore excluded from the study. Most patients included in the non-smoker cohort were female (69,702) and participants had a mean age of 50.1 years. Among this group, 13.5% had PUD and 13.3% had GERD. Patients with PUD were generally older, were more likely to have diabetes mellitus and hypertension, had a higher prevalence rate of alcohol, were more likely to exercise regularly and had higher blood pressure and cholesterol when compared with patients without PUD.

Multivariable analyses adjusting for factors including age, sex, hypertension, body mass index (BMI), alcohol intake, cholesterol and exercise habits showed SHS exposure was significantly linked to a higher risk of both PUD and GERD. Specifically, individuals exposed to SHS for at least 1 hour per week had a 1.23 times greater risk of developing PUD and a 1.20 times greater risk of GERD compared to those with no exposure.

The inclusion of a large sample of patients strengthened the study, while the cross-sectional design was considered a limitation, according to investigators. Additionally, they did not assess the durations of the gastrointestinal conditions, so causal relationships between SHS with PUD and GERD could not be evaluated. As the occurrence of these conditions were determined using questionnaires, the type and severity could not be determined, which could lead to recall bias and misclassification. Investigators were also unable to perform subgroup analyses on the extent and amount of SHS, the place and distance of exposure, and the brand of cigarette. Lastly generalizability of the findings could be limited by the ethnicity of patients (Chinese) and because most participants were female.

“This study represents the largest population-based investigation to date to explore the association between SHS with PUD and GERD in Taiwanese never-smokers,” investigators concluded.