Leisure-time exercise at younger age is associated with an increased risk of AF, whereas walking/bicycling at older age is associated with a decreased risk.

These findings indicate that alcohol consumption, even at moderate intakes, is a risk factor for atrial fibrillation.

During the last year exhaled nitric oxide (NO) has been proposed as a marker of airway inflammation. More knowledge of the production and transfer of this molecule are needed in order for NO analysis to become a clinical tool. This was the aim of the study. Exhaled NO values from multiple flow rates were used to model alveolar NO, transfer rate and tissue concentration of NO in the airways. Three flows rates, 0.005, 0.1 and 0.51 sec(-1) were found to be optimal. The NO transfer rate of the airways was 9 +/- 2 ml sec(-1), the tissue source was 75 +/- 28 ppb and the alveolar fraction of NO was 2 +/- 1 ppb in 10 healthy subjects (mean +/- CI95%). In conclusion, we have shown that it is possible to get more information about the distribution of NO in the lungs and the airways than only a single value from one expiratory flow rate can give. Further studies will reveal if this airway modelling can be useful in disease of the respiratory system.

Objective Previous studies have found that regular participation in intense physical activity increases the risk of developing atrial fibrillation (AF) in men, but it remains unclear how physical activity influences the risk of AF in women. We aimed to examine whether physical activity of different types and at different ages influences the development of AF in women. Methods In the population-based Swedish Mammography Cohort, information about physical activity was obtained from 36 513 AF-free women (49-83 years old, median age 60 years) who had completed a questionnaire at study entry (1997). Participants reported their time spent on leisure-time exercise and on walking or bicycling throughout their lifetime (at study entry, and at 30 and 50 years of age). We used the Swedish National Inpatient Register (IPR) to determine whether the participants were diagnosed with AF. Cox proportional hazards regression models were used to estimate relative risks (RR) with 95% CI, adjusted for potential confounders. Results During a median follow-up of 12 years (10th percentile 7.5 years, 90th percentile 12.0 years), 2915 cases of AF were diagnosed. The risk of AF decreased with increasing levels of leisure-time exercise at study entry (RR 0.85, 95% CI 0.75 to 0.95 for ≥4 h/week vs <1 h/week) and walking/bicycling (RR 0.81, 95% CI 0.72 to 0.92, for ≥40 min/day vs almost never). Conclusions Physical activity is associated with a reduced risk of AF in women. Moderate amount of physical activity was sufficient to significantly reduce AF risk.