Joint Effects of Carbon Black Exposure and Dietary Antioxidant Vitamin Intake on Small Airway Dysfunction

Causal relationship between air pollution and chronic obstructive pulmonary disease in European and East Asian populations: a Mendelian randomization study

Epidemiologic studies have suggested a possible association between air pollution and chronic obstructive pulmonary disease (COPD), but it is controversial and difficult to draw causal inferences. Five methods were adopted to evaluate the causal relationship between air pollution and COPD in European and East Asian populations by using MR Analysis. A statistically significant causal relationship between PM2.5 and COPD was observed in the European population (OR: 2.34; 95% CI: 1.06-5.05; p = 0.033). Statistical significance remained after adjustment for confounding factors (adjusted OR: 2.28; 95% CI: 1.01-5.20; p = 0.048). In East Asian populations, PM2.5 absorbance, a proxy for black carbon, was statistically associated with COPD (OR: 1.41; 95% CI: 1.09-1.81; p = 0.007). We did not adjust for confounders in East Asian populations, as the association was independent of known confounders (e.g. smoking, respiratory tract infections, etc.). In conclusion, increased concentrations of PM2.5 and PM2.5 absorbance were associated with an increased risk of COPD.

Preoperative small airway dysfunction is associated with skeletal muscle loss in early-stage non-small cell lung cancer

BACKGROUND

Postoperative skeletal muscle loss (SM loss) was reported to be associated with a poor prognosis in early-stage non-small cell lung cancer (NSCLC). Small airway dysfunction (SAD) is a common but neglected respiratory abnormality. Little information is known about the association between preoperative SAD and postoperative SM loss in early-stage NSCLC. Therefore, this study aimed to investigate the correlation between preoperative SAD and SM loss after surgery in early-stage NSCLC patients.

METHODS

There were 348 NSCLC patients with stages I-IIIA in this study from January 2017 to December 2020. All CT images were contrast-enhanced scans, and the skeletal muscle index (SMI) was measured using CT images. A 10.0% decrease in SMI over 12 months was determined as the cut-off value to define excessive SM loss. Logistic regression analyses were used to examine the relationship between SAD and SM loss.

RESULTS

This study included 348 subjects who underwent pulmonary operation (159 males and 189 females; mean age: 57.5 ± 8.8 years). 152 (43.7%) patients were identified as having SAD before surgery, and 179 patients (51.4%) were identified as having SM loss after 1 year. Moreover, a higher incidence of SAD was found in the SM loss group compared with that in the non-SM loss group (52.0% vs. 34.9%, p = 0.001). The patients with SAD were older, had larger tumor size, and had lower albumin levels. Furthermore, there were significant correlations between the lung function parameters manifesting SAD and the percentage change in SMI (for the forced expiratory flow when 75% of forced vital capacity has been exhaled (FEF75%), Pearson r=-0.107, p = 0.046; for FEF50%, r = -0.142, p = 0.008; and for FEF25-75%, r=-0.124, p = 0.021; respectively). However, no significant correlations were found between SMI and the lung function parameters reflecting proximal airway obstruction (p > 0.05). Logistic regression analysis revealed that preoperative SAD (HR, 2.465; 95% CI, 1.256-4.838; p = 0.009) was independent risk factor for postoperative SM loss in early-stage NSCLC. In addition, multivariable analysis revealed that SAD (HR, 1.816; 95% CI, 1.025-3.216, P = 0.041) were associated with postoperative complications.

CONCLUSION

Preoperative SAD is significantly associated with postoperative complications and SM loss in early NSCLC patients. Our results suggest that preoperative assessment of SAD may be useful for risk stratification of surgical candidates with potential for targeted interventions.

Association between Glucose-6-Phosphate Dehydrogenase Deficiency and Asthma

Background: Among the determinants contributing to the pathogenesis of asthma, antioxidant genetic factors play a leading role. Glucose-6-phosphate dehydrogenase (G6PD) is an enzyme that is competent to detoxify free radicals. Although a relationship between G6PD deficiency and asthma has been previously reported, the literature is still scanty. In this study, we test this hypothesis in a large cohort of patients from Sardinia, Italy. Methods: A retrospective case–control study was performed using data from 11,829 clinical records of outpatients referred to a teaching hospital for a medical visit. In total, 455 cases (asthma-positive) and 11,374 controls (asthma-negative) were compared for G6PD status using multivariable analysis, adjusting for all covariates. Results: Overall, G6PD deficiency was detected in 11.2% of study participants and was associated with an increased risk of asthma (odds ratio (OR) 1.63; 95% confidence interval (CI) 1.27–2.10). Additional variables significantly associated with asthma were female sex (OR 1.66; 95% CI 1.34–2.06), overweight/obesity (OR 1.56; 95% CI 1.27–1.92), smoking (OR 1.44; 95% CI 1.449–3.963), and high socioeconomic status (OR 1.40; 95% CI 1.16–1.70), whereas age was inversely related with asthma (OR 0.49; 95% CI 0.39–0.61). Conclusions: Our study shows that G6PD deficiency is an independent risk for asthma. These findings suggest that G6PD should be assessed in asthmatic patients for better risk stratification.