COPD exacerbation rates are higher in non-smoker patients in India

The severity of non-smoking chronic obstructive pulmonary disease is correlated with biomass fuel exposure and COPD assessment test score

BACKGROUND AND OBJECTIVE

Tobacco smoking is an established risk factor for chronic obstructive pulmonary disease (COPD). Current evidence suggests that non-tobacco-related risk factors vary geographically and are less understood than smoking. This study aims to compare the risk factors, symptoms, and clinical features of smoking (S-COPD) and non-smoking (NS-COPD) in a COPD population.

MATERIALS AND METHODS

In this retrospective cross-sectional study, 489 COPD patients were screened. Data on socio-demographics, smoking and medical history, other risk factors, symptoms, and clinical characteristics including COPD Assessment Test (CAT) score, and Modified Medical Research Council (mMRC) Dyspnea Scale were examined.

RESULTS

Of the total selected 416 COPD patients, 35.34% were NS-COPD while 64.66% were S-COPD. S-COPD was predominant in males, whereas NS-COPD was predominant in females (P < 0.0001). In NS-COPD, biomass fuel exposure was a major risk factor (P < 0.0001), and 61% of subjects had a biomass fuel exposure index of >60. In bivariate and multivariate analyses, no risk factors were correlated with forced expiratory volume in 1 second (FEV1)% predicted, while among clinical features, duration of illness (P = 0.001) was correlated with lower values of FEV1 in the multivariate table of S-COPD. In the multivariate analysis, biomass fuel exposure (P = 0.039) and CAT score (P < 0.0001) were correlated with FEV1(%) in NS-COPD.

CONCLUSION

Biomass fuel exposure is a substantial risk factor for NS-COPD and was correlated with FEV1(%) predicted. In addition, the CAT score correlated with disease severity in patients with NS-COPD. The development of COPD in non-smokers is being recognized as a separate phenotype and it should be managed according to risk factors.

Alterations of Macular Structure in Non-Glaucomatous Subjects With Obstructive Pulmonary Function

Purpose

The purpose of this study was to identify possible associations between obstructive pulmonary function and macular structure parameters on optical coherence tomography (OCT) and angiography in subjects without glaucomatous optic neuropathy.

Methods

A total of 70 patients were prospectively enrolled from June to December 2021 as a part of All About Life Yongin-Pulmonary/Psychiatry, Rehabilitation, Eye (AALY PRE) cohort in Yongin Severance Hospital. Patients underwent intraocular pressure (IOP), visual acuity measurements, cirrus OCT, OCT angiography, and pulmonary function testing (PFT) on the same day. Subjects with glaucomatous optic nerve damage were excluded. Those whose first second of forced expiration (FEV1) to forced vital capacity (FVC) ratio was below 70% were diagnosed with obstructive pulmonary function. Vessel densities (VDs) of retinal superficial vascular plexus were compared.

Results

Patients with obstructive function (n = 30) were significantly older than those with normal pulmonary function (n = 40, P < 0.001). After adjusting for age, IOP, and average ganglion cell-inner plexiform layer (GCIPL) thickness, macular VD was significantly decreased in all sectors except for the nasal sector in subjects with obstructive pulmonary function in comparison to those with normal function (P = 0.006). Multivariate regression analysis demonstrated that macular VD was linearly associated with FEV1/FVC (β = 0.102, P = 0.031). In subjects with obstructive function, the severity of pulmonary obstruction, FEV1, was linearly associated with GCIPLT (β = 0.302, P = 0.017).

Conclusions

Obstructive pulmonary function is associated with reduced macular VD in subjects without glaucoma. Among subjects with obstructive pulmonary function, the severity of pulmonary obstruction is associated with GCIPL thickness in the macular region. Further studies are needed on the relationship between pulmonary function and macular disease.

A2M Serves as Promising Biomarker for Chronic Obstructive Pulmonary Disease

Background

Chronic obstructive pulmonary disease (COPD) often associated with cigarette smoking. However, increasing evidence suggests that non-smoking COPD is much higher than previously thought. This study aims to identify a nonsmoking COPD biomarker and examined its value in diagnosis and prediction of acute exacerbation.

Methods

A total of 35 stable COPD patients, 70 acute exacerbation chronic obstructive pulmonary disease (AECOPD) patients and 35 healthy control subjects were included. Plasma α 2 macroglobulin (A2M) and matrix metalloproteinase-9 (MMP-9) levels were measured using the enzyme-linked immunosorbent assay (ELISA) method on all participants. Their association with clinical characteristics and lung function parameters were determined by regression analysis. Receiver operating characteristic (ROC) curve was used to determine the diagnostic sensitivity and specificity. Correlation coefficients were evaluated using Pearson's correlation.

Results

Plasma A2M concentration was decreased and MMP-9 concentration, MMP-9/A2M ratio were elevated in stable COPD patients compared with control groups. And MMP-9 expression was significantly higher in AECOPD patients. A2M level was increased in AECOPD patients with infection compared with those without. In addition, there was no statistical difference in A2M levels between smokers and nonsmokers COPD or healthy control subjects. Furthermore, A2M, MMP-9 and MMP-9/A2M were correlated with forced expiratory volume in one second (FEV₁)%, FEV₁/ forced vital capacity (FVC), CAT and mMRC score in COPD patients, but had no correlation with fraction of exhaled nitric oxide (FeNO) and concentration of alveolar nitric oxide (CaNO).

Conclusion

A2M is altered in peripheral blood of COPD patients and correlated with severity and infection. Moreover, there was no significant correlation between the change in A2M and smoking, FeNO and CaNO, suggesting A2M may reflect the overall rather than local inflammation in COPD patients and serve as a potential biomarker for nonsmoking COPD patients.

Clinical and microbiological characteristics and inflammatory profile during an exacerbation of COPD due to biomass exposure. A comparison with COPD due to tobacco exposure

BACKGROUND

Patients with biomass exposure-related COPD (BE-COPD) is a prevalent disease in developing countries and requires a detailed study of its clinical and inflammatory characteristics, specifying interventions that may differ from tobacco exposure-related COPD (TE-COPD). The objective was to describe clinical characteristics, biomarkers of inflammation, T-helper cells, and microbiological agents during a COPD exacerbation in BE-COPD in comparison with TE-COPD.

METHODS

A prospective observational study in patients with moderate or severe exacerbation was recruited either in the emergency room or the COPD clinic. At enrollment, nasopharyngeal swabs and sputum were collected to identify viral and bacterial pathogens. Blood samples were also collected to measure inflammatory biomarkers and T-helper cells levels. Days of hospitalization and mechanical ventilation requirement was evaluated.

RESULTS

Clinical characteristics, vaccination history, hospitalization, history of exacerbations, and microbiological pattern between BE-COPD and TE-COPD were similar. The Th2 profile was higher in BE-COPD than in TE-COPD (2.10 [range 1.30-3.30] vs. 1.40 [range 1.20-1.80], p = 0.001). The Th2/Th1 ratio was higher in BE-COPD than TE-COPD (1.22 [range 0.58-2.57 ] vs. 0.71 [range 0.40-1.15], p = 0.004). The need of mechanical ventilation (MV) was higher in TE-COPD than BE-COPD (13% vs. 31.1%, p = 0.01). Nonvaccination history and high CRP levels were significantly associated with hospitalization [OR 1.48 (CI 95% 1.30-4.61, p = 0.005) and OR 1.17 (CI 95% 1.10-1.24, p = 0.001), respectively].

CONCLUSIONS

Clinical characteristics, inflammatory markers, and microbiological isolates were similar in both groups but BE-COPD show a tendency to present higher inflammatory Th2 cells and low requirement MV compared with TE-COPD.

Increased risk of open-angle glaucoma in non-smoking women with obstructive pattern of spirometric tests

To investigate differences in the prevalence of open-angle glaucoma (OAG) between different pulmonary function types. A population-based, cross-sectional analysis was conducted using Korean National Health and Nutrition Examination Surveys from 2008 to 2011. A total of 8941 subjects  ≥ 40 years of age were analyzed. Chronic obstructive pulmonary disease (COPD) was defined as the ratio between first second of forced expiration (FEV1) and forced vital capacity (FVC) below 70%. The prevalence of glaucoma, as defined by the International Society of Geographical and Epidemiological Ophthalmology, was the main outcome. OAG was more prevalent in women with COPD (8.0% vs. 4.8% normal, P = 0.001) compared to women with normal pulmonary function. Intraocular pressure (IOP) of women with COPD were 13.3 (0.2) mmHg (13.9 (0.1) mmHg for normal function, P = 0.182). Never-smokers were more prevalent in women with COPD and glaucoma (92.9% vs. 52.4% normal function; P < 0.001). COPD was found to increase the risk of glaucoma in women (OR 2.077, P = 0.017) and even further in non-smoking women (OR 2.711, P = 0.003). Women with COPD showed a higher glaucoma prevalence despite similar IOP in comparison to women with normal pulmonary function. Non-smoking COPD is significantly associated with open-angle glaucoma in women.

Incidence and profile of severe exacerbations of chronic obstructive pulmonary disease due to biomass smoke or tobacco

INTRODUCTION AND OBJECTIVES:

Stable chronic obstructive pulmonary disease (COPD) caused by biomass smoke (B-COPD) has some differences from tobacco-induced-COPD (T-COPD), but acute exacerbations (AECOPD) have not been well characterized in B-COPD.

OBJECTIVE:

To compare the incidence, characteristics and outcomes of AECOPD in B-COPD with those of T-COPD.

METHODS:

A retrospective observational study that included consecutive patients seen at a specialized COPD clinic (2008–2021). The incidence of severe AECOPD that required hospital admission was studied. For the first AECOPD, the following variables were recorded: fever, coexistence of pneumonia, purulent sputum, eosinophil count, neutrophil to lymphocyte ratio, hypercapnia, and respiratory acidosis. Outcome variables were intensive care unit (ICU) admission, length of hospital stay, and mortality within 1 month of hospital admission.

RESULTS:

Of 1060 subjects, 195 (18.4%) belonged to the B-COPD group and 865 (81.6%) to the T-COPD group. During a follow-up of 67.9 (37.8–98.8) months, 75 (38.4%) patients in the B-COPD group and 319 (36.8%) in the T-COPD group suffered at least one severe AECOPD. The only difference between groups was in a higher risk of ICU admission for the T-COPD group. The incidence, characteristics, and the rest of the outcomes of AECOPD were similar for both groups.

CONCLUSION:

AECOPD are similar events for B-COPD and T-COPD and should be managed similarly.