Marios Kougias

Short-term Pulmonary Effects of Using an Electronic Cigarette Impact on Respiratory Flow Resistance, Impedance, and Exhaled Nitric Oxide

BACKGROUND Debate exists over the scientific evidence for claims that electronic cigarettes (e-cigarettes) have no health-related ramifications. This study aimed to assess whether using an e-cigarette for 5 min has an impact on the pulmonary function tests and fraction of exhaled nitric oxide (Feno) of healthy adult smokers. METHODS Thirty healthy smokers (aged 19-56 years, 14 men) participated in this laboratory-based experimental vs control group study. Ab lib use of an e-cigarette for 5 min with the cartridge included (experimental group, n = 30) or removed from the device (control group, n = 10) was assessed. RESULTS Using an e-cigarette for 5 min led to an immediate decrease in Feno within the experimental group by 2.14 ppb (P = .005) but not in the control group (P = .859). Total respiratory impedance at 5 Hz in the experimental group was found to also increase by 0.033 kPa/(L/s) (P < .001), and flow respiratory resistance at 5 Hz, 10 Hz, and 20 Hz also statistically increased. Regression analyses controlling for baseline measurements indicated a statistically significant decrease in Feno and an increase in impedance by 0.04 kPa/(L/s) (P = .003), respiratory resistance at 5 Hz by 0.04 kPa/(L/s) (P = .003), at 10 Hz by 0.034 kPa/(L/s) (P = .008), at 20 Hz by 0.043 kPa/(L/s) (P = .007), and overall peripheral airway resistance (β, 0.042 kPa/[L/s]; P = .024), after using an e-cigarette. CONCLUSIONS e-Cigarettes assessed in the context of this study were found to have immediate adverse physiologic effects after short-term use that are similar to some of the effects seen with tobacco smoking; however, the long-term health effects of e-cigarette use are unknown but potentially adverse and worthy of further investigation.

Original ResearchTobacco Cessation and PreventionShort-term Pulmonary Effects of Using an Electronic Cigarette: Impact on Respiratory Flow Resistance, Impedance, and Exhaled Nitric Oxide

BACKGROUND Debate exists over the scientific evidence for claims that electronic cigarettes (e-cigarettes) have no health-related ramifications. This study aimed to assess whether using an e-cigarette for 5 min has an impact on the pulmonary function tests and fraction of exhaled nitric oxide (Feno) of healthy adult smokers. METHODS Thirty healthy smokers (aged 19-56 years, 14 men) participated in this laboratory-based experimental vs control group study. Ab lib use of an e-cigarette for 5 min with the cartridge included (experimental group, n = 30) or removed from the device (control group, n = 10) was assessed. RESULTS Using an e-cigarette for 5 min led to an immediate decrease in Feno within the experimental group by 2.14 ppb (P = .005) but not in the control group (P = .859). Total respiratory impedance at 5 Hz in the experimental group was found to also increase by 0.033 kPa/(L/s) (P < .001), and flow respiratory resistance at 5 Hz, 10 Hz, and 20 Hz also statistically increased. Regression analyses controlling for baseline measurements indicated a statistically significant decrease in Feno and an increase in impedance by 0.04 kPa/(L/s) (P = .003), respiratory resistance at 5 Hz by 0.04 kPa/(L/s) (P = .003), at 10 Hz by 0.034 kPa/(L/s) (P = .008), at 20 Hz by 0.043 kPa/(L/s) (P = .007), and overall peripheral airway resistance (β, 0.042 kPa/[L/s]; P = .024), after using an e-cigarette. CONCLUSIONS e-Cigarettes assessed in the context of this study were found to have immediate adverse physiologic effects after short-term use that are similar to some of the effects seen with tobacco smoking; however, the long-term health effects of e-cigarette use are unknown but potentially adverse and worthy of further investigation.

The acute effect of cigarette smoking on the respiratory function and FENO production among young smokers.

ABSTRACT Introduction: Smoking is known to have a long-term impact on lung function; however, the acute physiological response of smoking a single cigarette and the influential role of pack years and cigarettes per day on pulmonary indices remains an area of interest, especially among young smokers. Methods: 50 naive smokers (ages: 18–26, 24 males: mean pack years 3.8) participated in this experimental study. Respiratory resistance (R), reactance (X ), and impedance (Z ) were assessed through impulse oscillometry. The participants’ fraction of exhaled nitric oxide (FENO) was measured. All tests were performed immediately before and after smoking one single cigarette. Results: Smoking a single cigarette was found to immediately increase airway impedance (Z 5 Hz) by 0.024kPa/(L/s) (P = .002), airway resistance at R 5 Hz, R 10 Hz, and R 20 Hz by 0.024kPa/(L/s)(P < .001), 0.016kPa/(L/s)(P = .019), and 0.023kPa/(L/s) (P = .007), respectively, after adjusting for BMI, age, gender, and pack years. FENO concentrations also decreased from 11.70 ppb to 9.85 ppb, P < .001. Sensitivity analyses indicated that the participants’ number of pack years and cigarettes per day influenced pulmonary reactance at 10 Hz and 20 Hz, however only at baseline with these differences found to disappear immediately after smoking. Conclusions: The present study indicates that the consumption of a single cigarette may alter lung mechanics and FENO production among young smokers. Further research is needed to assess the mechanisms and washout period after which these parameters return to normal.

Acute pulmonary effects of sidestream secondhand smoke at simulated car concentrations

1. Exposure to secondhand smoke (SHS) can occur in many places; however, regulations banning smoking may reduce the sources of exposure to SHS to personal areas such as the family car, a source of brief but potently intense exposure. 2. Fifteen non-smoking volunteers were exposed to sidestream SHS concentrations of 5000 µg/m3, within a simulated car setting. The Fraction of Exhaled Nitric Oxide (FeNO) was calculated, dynamic flow volumes were assessed through spirometry; while airway impedance (Z), resistance (R), and reactance (X) was assessed through impulse oscillometry before and after exposure. 3. Exposure to sidestream SHS within this experimental condition did not affect dynamic flow volumes, however FENO decreased from 15.34 ppb to 11.15 ppb, (p < 0.001). Increases in airway resistance at R5Hz by 0.114 kPa/(L/s) (p = 0.002), at R10Hz by 0.093[kPa/(L/s)] (p = 0.006) and at R20Hz by 0.093[kPa/(L/s)] (p = 0.008) were noted. Correspondingly overall peripheral and central airway resistance was also found to increase by 40% (by 0.083 kPa/(L/s), p = 0.038) and 25% (by 0.045 kPa/(L/s), p = 0.047) respectively. 4. Brief but elevated exposure to sidestream SHS can alter airway resistance, and impedance indicating a potential additional mechanistic pathway between exposure to SHS and the development of respiratory disease. Further research is needed to verify these pilot results.

Exhaled carbon monoxide as a marker of lung aging in smokers presenting with mild air flow limitation

Background The measurement of exhaled carbon monoxide (CO) level may provide an immediate, noninvasive method of assessing smoking status. In addition CO is a molecule generally presumed to be a marker of oxidative stress and inflammation when endogenously produced. Many reports have focused on increased endogenous CO production in pulmonary diseases, including asthma and COPD. The purpose of our study is to highlight special characteristics in smokers with mild airflow limitation, in correlation with exhaled CO measurements.