Short-term respiratory effects of e-cigarettes in healthy individuals and smokers with asthma.

BACKGROUND AND OBJECTIVE: This study investigated the duration of immediate respiratory effects of e-cigarette smoking (ECS) and tested the hypothesis that ECS has more prominent effects in asthmatics compared with healthy smokers (HS). METHODS: Fifty-four smokers, 27 healthy (HS group) and 27 with intermittent asthma (mild asthma (MA) group) underwent a control session (no liquid, no resistor coil inside e-cigarette cartridge) and an experimental session of ECS using standardized puffing settings. Impulse oscillometry impedance (Z), resistance (R), reactance (X) and fractional exhaled nitric oxide (FeNO) were measured before and 0, 15 and 30 min after control and experimental sessions. RESULTS: Control session revealed no significant changes. In the experimental session, immediately post-ECS, both groups exhibited a significant increase in respiratory system total impedance at 5 Hz (Z5) (P < 0.001), respiratory system resistance at 5 Hz (R5) (P < 0.001), respiratory system resistance at 10 Hz (R10) (P < 0.001), respiratory system resistance at 20 Hz (R20) (P < 0.05), resonant frequency (P < 0.001) and reactance area (P < 0.05). MA exhibited higher baseline values and a more prominent effect immediately after ECS compared with HS for Z5 (P = 0.022), R5 (P = 0.010) and R10 (P = 0.013). FeNO decreased significantly in both groups (P < 0.001); HS returned to baseline values in ≤15 min while the MA maintained significantly lower values for an additional 15 min (P < 0.05) and returned to baseline values at 30 min post-ECS. CONCLUSION: A single session of ECS had respiratory mechanical and inflammatory effects, which were more prominent in smokers with asthma.

Exhaled Breath Condensate: Technical and Diagnostic Aspects.

PURPOSE: The aim of this study was to evaluate the 30-year progress of research on exhaled breath condensate in a disease-based approach. METHODS: We searched PubMed/Medline, ScienceDirect, and Google Scholar using the following keywords: exhaled breath condensate (EBC), biomarkers, pH, asthma, gastroesophageal reflux (GERD), smoking, COPD, lung cancer, NSCLC, mechanical ventilation, cystic fibrosis, pulmonary arterial hypertension (PAH), idiopathic pulmonary fibrosis, interstitial lung diseases, obstructive sleep apnea (OSA), and drugs. RESULTS: We found 12600 related articles in total in Google Scholar, 1807 in ScienceDirect, and 1081 in PubMed/Medline, published from 1980 to October 2014. 228 original investigation and review articles were eligible. CONCLUSIONS: There is rapidly increasing number of innovative articles, covering all the areas of modern respiratory medicine and expanding EBC potential clinical applications to other fields of internal medicine. However, the majority of published papers represent the results of small-scale studies and thus current knowledge must be further evaluated in large cohorts. In regard to the potential clinical use of EBC-analysis, several limitations must be pointed out, including poor reproducibility of biomarkers and absence of large surveys towards determination of reference-normal values. In conclusion, contemporary EBC-analysis is an intriguing achievement, but still in early stage when it comes to its application in clinical practice.

Immediate effects of cigar smoking on respiratory mechanics and exhaled biomarkers; differences between young smokers with mild asthma and otherwise healthy young smokers.

BACKGROUND: We aimed to investigate the immediate respiratory effects of cigar smoking(CS), among young smokers with and without mild asthma. MATERIALS AND METHODS: Forty-seven young smokers (18-31years old, 29 males, average pack-years = 3.6 ± 2.8) were enrolled. Twenty-two were mild asthmatics(MA-subgroup) and the remaining 25 were otherwise healthy smokers(HS-subgroup). Exhaled carbon monoxide(eCO), multi-frequency respiratory system impedance(Z), resistance(R), reactance(X), frequency-dependence of resistance(fdr = R5Hz - R20Hz), resonant frequency(fres), reactance area(AX) and exhaled nitric oxide(FENO) were measured at the aforementioned sequence, before and immediately after 30 min of CS, or equal session in the smoking area while using a sham cigar(control group). Chi-square, student's t-tests, mixed linear models and Pearson correlation tests were used for the statistical analysis; level of significance was defined as p < 0.05. RESULTS: Immediately after CS, Z5Hz, R5Hz, R10Hz, R20Hz and eCO increased significantly in both subgroups(MA and HS). A greater increase was found for R20 in HS-subgroup. Fdr, fres and AX increased in MA, while decreased in HS. On the contrary, X10 decreased in MA and increased in HS, while X20 showed a greater decrease in MA. Changes in fdr, fres and AX were significantly correlated in both subgroups. No significant FENO alterations were detected in both subgroups. CONCLUSION: CS has immediate effects on pulmonary function. Mild asthma predisposes to higher increase of peripheral resistance(increased fdr). In otherwise healthy smokers, central resistance(R20Hz) is more affected. FENO levels are not significantly affected by CS.