Gastroesophageal reflux disease is a risk factor for sputum production in the general population: the Nagahama study

Abstract

Background Chronic sputum production in the general population is historically associated with clinical indices including male sex and smoking history. However, its relationship with gastroesophageal reflux disease (GERD), which may prove an underlying factor in sputum production, is unclear. We aimed to clarify factors associated with sputum production in the general population in cross-sectional and longitudinal manners. Methods In the Nagahama study, a community-based cohort study, 9804 subjects were recruited between 2008 and 2010 (baseline assessment), 8293 of whom were followed from 2013 to 2015 (follow-up assessment). This study contained a self-completed questionnaire which included medical history, assessment of sputum production, and a frequency scale for symptoms of GERD. A Frequency Scale for Symptoms of Gastroesophageal Reflux Disease score of ≥ 8 was defined as GERD. In addition to the frequency of sputum production at each assessment, frequency of persistent sputum production defined as sputum production at both assessments was examined. Results Frequency of sputum production was 32.0% at baseline and 34.5% at follow-up. Multivariable analysis demonstrated that sputum production at baseline was significantly associated with GERD [odds ratio (OR), 1.92; 95% confidence interval (CI) 1.73–2.13] and post-nasal drip (PND) (OR, 2.40; 95% CI 2.15–2.68), independent of other known factors such as older age, male sex and smoking history. These associations between sputum production and GERD or PND were also observed at follow-up. In longitudinal analysis, 19.4% had persistent sputum production and 12.3% had transient sputum production, i.e., at baseline only. Multivariable analysis for risk of persistence of sputum production revealed that persistent sputum production was associated with GERD and PND, in addition to the known risk factors listed above. The proportion of subjects with GERD at both assessments was highest among subjects with persistent sputum production. Conclusions Cross-sectional and longitudinal analysis demonstrated an association in the general population between sputum production and GERD, as well as PND, independent of known risk factors. The presence of GERD should be assessed in patients complaining of sputum production.

Sputum production in chronic cough increases the probability of asthma: a cross-sectional questionnaire study

“…Furthermore, our study showed that the number of cough background disorders is associated with sputum production. These findings, alongside the findings of the previously mentioned Japanese study [ 13 ], suggest that the presence of sputum production in a patient with chronic cough should encourage a clinician to seek treatable cough background disorders especially carefully.…”

“…Sputum production was not statistically significantly associated with UACS or GORD in the present study. In a previous large Japanese study, both were statistically significantly associated with sputum production [ 13 ]. Different populations may explain this discrepancy.…”

Spotlight on: Nature, assessment, and management of laryngopharyngeal reflux

“…Many studies examining the relationship between these conditions fail to adequately discriminate between LPR and GORD (Lechien et al, 2023). One study demonstrated a positive relationship between allergic rhinitis and LPR presence (Alharethy et al, 2018), while another identified that GORD is significantly associated with the presence of post-nasal drip (Morimoto et al, 2021). Liu et al (2023) noted that the effects of LPR on quality of life are complicated by poor discrimination between LPR and GORD.…”