Inflammatory Markers: Exhaled Nitric Oxide and Carbon Monoxide During the Ovarian Cycle

Nitric oxide (NO) production and carbon monoxide (CO) production are increased in inflammatory lung diseases. Although there are some pieces of evidence for hormonal modulation by estrogen, little is known about exhaled NO and CO during the ovarian cycle. In 23 subjects, we measured exhaled NO and CO by an online analyzer. Significantly higher levels of exhaled NO were found at the midcycle compared with those in the premenstrual period or during menstruation. Higher levels of CO were after ovulation and reached a peak in the premenstrual phase. The lowest levels of CO were observed in the first days of the estrogen phase. In males, there was no significant variation in exhaled NO and CO. Exhaled NO and CO levels vary during the ovarian cycle in women, and this fact should be taken into account during serial measurements of these markers in the female population

Standardised exhaled breath collection for the measurement of exhaled volatile organic compounds by proton transfer reaction mass spectrometry

BACKGROUND: Exhaled breath volatile organic compound (VOC) analysis for airway disease monitoring is promising. However, contrary to nitric oxide the method for exhaled breath collection has not yet been standardized and the effects of expiratory flow and breath-hold have not been sufficiently studied. These manoeuvres may also reveal the origin of exhaled compounds. METHODS: 15 healthy volunteers (34 +/- 7 years) participated in the study. Subjects inhaled through their nose and exhaled immediately at two different flows (5 L/min and 10 L/min) into methylated polyethylene bags. In addition, the effect of a 20 s breath-hold following inhalation to total lung capacity was studied. The samples were analyzed for ethanol and acetone levels immediately using proton-transfer-reaction mass-spectrometer (PTR-MS, Logan Research, UK). RESULTS: Ethanol levels were negatively affected by expiratory flow rate (232.70 +/- 33.50 ppb vs. 202.30 +/- 27.28 ppb at 5 L/min and 10 L/min, respectively, p < 0.05), but remained unchanged following the breath hold (242.50 +/- 34.53 vs. 237.90 +/- 35.86 ppb, without and with breath hold, respectively, p = 0.11). On the contrary, acetone levels were increased following breath hold (1.50 +/- 0.18 ppm) compared to the baseline levels (1.38 +/- 0.15 ppm), but were not affected by expiratory flow (1.40 +/- 0.14 ppm vs. 1.49 +/- 0.14 ppm, 5 L/min vs. 10 L/min, respectively, p = 0.14). The diet had no significant effects on the gasses levels which showed good inter and intra session reproducibility. CONCLUSIONS: Exhalation parameters such as expiratory flow and breath-hold may affect VOC levels significantly; therefore standardisation of exhaled VOC measurements is mandatory. Our preliminary results suggest a different origin in the respiratory tract for these two gasses

Exhaled 8-isoprostane in childhood asthma

Abstract Background Exhaled breath condensate (EBC) is a non-invasive method to assess airway inflammation and oxidative stress and may be useful in the assessment of childhood asthma. Methods Exhaled 8-isoprostane, a stable marker of oxidative stress, was measured in EBC, in children (5–17 years) with asthma (13 steroid-naïve and 12 inhaled steroid-treated) and 11 healthy control. Results Mean exhaled 8-isoprostane concentration was significantly elevated in steroid-naïve asthmatic children compared to healthy children 9.3 (SEM 1.7) vs. 3.8 (0.6) pg/ml, p Conclusion We conclude that 8-isoprostane is elevated in asthmatic children, indicating increased oxidative stress, and that this does not appear to be normalized by inhaled steroid therapy. This suggests that 8-isoprostane is a useful non-invasive measurement of oxidative stress in children and that antioxidant therapy may be useful in the future.</p

Increased 8-isoprostane, a marker of oxidative stress, in exhaled condensate of asthma patients

Oxidative stress has an important role in the pathogenesis of asthma. 8-Isoprostane is a prostaglandin (PG)-F 2–like compound belonging to the F 2 isoprostane class that is produced in vivo by the free radical-catalyzed peroxidation of arachidonic acid. 8-Isoprostane is a biomarker of oxidative stress, and its concentration is increased in the bronchoalveolar lavage fluid of patients with interstitial lung diseases. We measured 8-isoprostane concentrations in exhaled breath condensate in healthy subjects and in patients with mild (steroid naive, n � 12), moderate (inhaled steroid treatment, n � 17), and severe asthma (oral steroid treatment, n � 15). We also measured exhaled carbon monoxide (CO) and nitric oxide (NO), which may also reflect oxidative stress in the airways. 8-Isoprostane was detectable in breath condensate of normal subjects (15.8 � 1.6 pg/ml), and was increased in the breath condensate of patients with mild (33.7 � 2.8, p � 0.001), moderate (38.3 � 3.7 pg/ml, p � 0.001), and severe asthma (48.9 � 5.0 pg/ml, p � 0.001). There was a positive correlation (r � 0.68, p � 0.05) of 8-isoprostane with NO, but not with CO, in the exhaled air of patients with mild asthma, but not in that of patients with moderate or severe asthma. There was no correlation between 8-isoprostane and lung function tests in any group of patients. Our study shows that oxidative stress is increased in asthmatic subjects as reflected by 8-isoprostane concentrations in breath condensate