Prevalence of chronic sputum and associated factors in Korean adults

Characteristics and Prevalence of Early Chronic Obstructive Pulmonary Disease in a Middle-Aged Population: Results from a Nationwide-Representative Sample

Introduction

Few studies have examined the prevalence and associated factors of early chronic obstructive pulmonary disease (COPD) in Asians.

Objective

To evaluate the prevalence of early COPD and its associated factors among non-institutionalized middle-aged Korean adults.

Methods

A total of 3195 participants aged 40–49 years from the 2016–2018 Korea National Health and Nutrition Examination Survey were included in this study. Patients (1) aged less than 50 years, (2) with a minimum of 10 pack-years of smoking, and (3) with forced expiratory volume in 1 s/forced vital capacity (FEV₁/FVC) below the lower limit of normal were diagnosed with early COPD. The prevalence and odds ratio (OR) for early COPD were measured using multivariate logistic regression analysis, and the demographic data, anthropometric measurements, socioeconomic status, and lifestyle factors were considered covariates.

Results

The overall prevalence of early COPD among the middle-aged Korean population was 2.4% (4.4% in men and 0.4% in women), while that in participants with ≥10 pack-years was 8.2% (8.1% in men and 11.3% in women). A multivariate logistic regression model showed that male sex, urban residence, chronic sputum production, and hypertriglyceridemia were associated with increased ORs for early COPD in middle-aged, non-institutionalized Korean adults.

Conclusion

Early COPD is prevalent among middle-aged smokers in Korea. Efforts are needed to reduce the potential negative effects of early COPD on public health in Korea and other Asian countries.

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

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.

Comparison of clinical characteristics in patients with Takayasu arteritis with and without concomitant tuberculosis

Because of frequent tuberculosis in patients with Takayasu arteritis (TA), a possible relationship between TA and tuberculosis has been proposed. However, there are no studies to date that have examined clinical manifestations in patients diagnosed with TA with or without tuberculosis. Two hundred sixty-seven patients were diagnosed with TA according to the 1990 American College of Rheumatology criteria between September 1994 and April 2014. Patients with TA were classified into groups with or without tuberculosis. Among the 267 patients with TA studied, 47 patients (17.7 %) who had a history of previous treatment of tuberculosis (34 patients), concurrent diagnosis of tuberculosis with TA (10 patients), or diagnosis of tuberculosis during the follow-up period for TA (3 patients) were included in the group with tuberculosis. The group with tuberculosis comprised of 33 patients (70.2 %) with pulmonary tuberculosis, 12 patients (25.5 %) with tuberculous lymphadenitis, and 2 patients (4.3 %) with tuberculosis of the skin and colon, respectively. Comorbid disease and patients' signs and symptoms were not significantly different between TA patients with and without tuberculosis. Additionally, the site of disease involvement in angiographic findings and distribution of angiographic type were similar between the two groups. In conclusion, tuberculosis including tuberculous lymphadenitis was frequently observed in patients with TA. Clinical features and angiographic findings in TA were not different according to the presence or absence of concomitant tuberculosis.