Altered levels of exhaled nitric oxide in rheumatoid arthritis.

BACKGROUND: Rheumatoid arthritis (RA) is an autoimmune disorder characterized by bone and joint destruction, but other organ systems can also be involved. Recent studies have suggested that the disease may start in the lungs. Exhaled nitric oxide (FENO) is a marker of inflammation. The aims of the study were to compare the NO parameters between subjects with RA and healthy control subjects, and to examine whether the NO parameters correlated with lung function and disease activity in the subjects with RA. METHODS: Subjects with RA (n = 35) were recruited during their regular outpatient visits to the rheumatology department. The nitric oxide (NO) parameters: alveolar NO concentration (CANO), airway compartment diffusing capacity of NO (DawNO), and tissue concentration of NO in the airway wall (CawNO), were algorithmically estimated. Healthy subjects (n = 35) matched by age, gender and height were used as controls. Data are given in median, (quartile 25, 75). Wilcoxon Matched Pairs test was used for group comparisons. Mann-Whitney U test was used to make comparisons between any two groups and for pairwise comparisons. Correlations were tested with Spearman rank order correlation. RESULTS: CANO was significantly lower in the RA subjects compared with healthy subjects; 1.1 (0.5, 1.8) ppb versus 2.4 (2.0, 3.0) ppb, (p < 0.001). CawNO was significantly lower in the RA subjects with 51 (22, 87) ppb versus 120 (76, 162) ppb in the control group. DawNO was significantly higher at 25 (15, 36) mL/s in the RA group versus the control group's 7.7 (5.3, 10.7) mL/s. CONCLUSIONS: There are significant differences between subjects with RA and matched healthy control subjects regarding the exhaled NO parameters. It is unclear if this can be explained by the pathogenesis of RA, consequences of long-term disease, and/or due to drug treatment.

Increased levels of alveolar and airway exhaled nitric oxide in runners.

AIM: The objective of this study was to apply extended NO analysis for measurements of NO dynamics in the lung, divided into alveolar and airway contribution, in amateur runners and marathoners. METHODS: The athletes participated in either a marathon or a half marathon. The athletes self-reported their age, weight, height, training distance per week, competing distance, cardio-pulmonary health, atopic status, and use of tobacco. Measurements of exhaled NO (FENO) with estimation of alveolar NO (CANO) and airway flux (JawNO), ventilation, pulse oximetry, and peak flow were performed before, immediately after, and 1 hour after completing the race. RESULTS: At baseline the alveolar NO was higher in amateur runners, 2.9 ± 1.1 ppb (p = 0.041), and marathoners, 3.6 ± 1.9 ppb (p = 0.002), than in control subjects, 1.4 ± 0.5 ppb. JawNO was higher in marathoners, 0.90 ± 0.02 nL s-1 (p = 0.044), compared with controls, 0.36 ± 0.02 nL s-1, whereas the increase in amateur runners, 0.56 ± 0.02 nL s-1, did not attain statistical significance (p = 0.165). Immediately after the race there was a decrease in FENO in both amateur runners and marathoners, whereas CANO and JawNO were decreased in marathoners only. CONCLUSION: Our results support the view that there is an adaptation of the lung to exercise. Thus strenuous exercise increased both airway and alveolar NO, and this might in turn facilitate oxygen uptake.