Predicting corticosteroid response in chronic obstructive pulmonary disease using exhaled nitric oxide.

RATIONALE: Predicting corticosteroid response in COPD is important but difficult. Response is more likely to occur in association with eosinophilic airway inflammation, for which the fraction of exhaled nitric oxide (Fe(NO)) is a good surrogate marker. OBJECTIVES: We aimed to establish whether Fe(NO) levels would predict the clinical response to oral corticosteroid in COPD. METHODS: We performed a double-blind, crossover trial of steroid in patients with COPD. After a 4-week washout of inhaled steroids, patients received prednisone 30 mg/d or matching placebo, in random order, with an intervening 4-week washout. The predictive values of Fe(NO) for clinically significant changes in 6-minute-walk distance (6MWD), spirometry (FEV(1)), and St. George's Respiratory Questionnaire (SGRQ) were calculated. MEASUREMENTS AND MAIN RESULTS: A total of 65 patients (mean FEV(1) = 57% predicted) were randomized. With prednisone, there was a net increase of 13 m in 6MWD (P = 0.02) and 0.06 L in postbronchodilator FEV(1) (P = 0.02) compared with placebo. The change in SGRQ was not significant. Using receiver operator characteristic analysis, the area under the curve for an increase of 0.2 L in FEV(1) was 0.69 (P = 0.04) with an optimum Fe(NO) cut-point of 50 ppb. The positive and negative predictive values were 67 and 82%, respectively. FE(NO) was not a significant predictor for changes in 6MWD or SGRQ. CONCLUSIONS: Fe(NO) is a weak predictor of short-term response to oral corticosteroid in COPD, its usefulness being limited to predicting increase in FEV(1). Clinical trial registered with www.anzctr.org.au (ACTRN12605000683639).

The effect of ambient air pollution on respiratory health of school children: a panel study.

BACKGROUND: Adverse respiratory effects of particulate air pollution have been identified by epidemiological studies. We aimed to examine the health effects of ambient particulate air pollution from wood burning on school-age students in Christchurch, New Zealand, and to explore the utility of urine and exhaled breath condensate biomarkers of exposure in this population. METHODS: A panel study of 93 male students (26 with asthma) living in the boarding house of a metropolitan school was undertaken in the winter of 2004. Indoor and outdoor pollution data was continuously monitored. Longitudinal assessment of lung function (FEV1 and peak flow) and symptoms were undertaken, with event studies of high pollution on biomarkers of exposure (urinary 1-hydroxypyrene) and effect (exhaled breath condensate (EBC) pH and hydrogen peroxide concentration). RESULTS: Peak levels of air pollution were associated with small but statistically significant effects on lung function in the asthmatic students, but not healthy students. No significant effect of pollution could be seen either on airway inflammation and oxidative stress either in healthy students or students with asthma. Minor increases in respiratory symptoms were associated with high pollution exposure. Urinary 1-hydroxypyrene levels were raised in association with pollution events by comparison with low pollution control days. CONCLUSION: There is no significant effect of ambient wood-smoke particulate air pollution on lung function of healthy school-aged students, but a small effect on respiratory symptoms. Asthmatic students show small effects of peak pollution levels on lung function. Urinary 1-hydroxypyrene shows potential as a biomarker of exposure to wood smoke in this population; however measurement of EBC pH and hydrogen peroxide appears not to be useful for assessment of population health effects of air pollution.Some of the data presented in this paper has previously been published in Kingham and co-workers Atmospheric Environment, 2006 Jan; 40: 338-347 (details of pollution exposure), and Cavanagh and co-workers Sci Total Environ. 2007 Mar 1;374(1):51-9 (urine hydroxypyrene data).

Self-management plans in the primary care of patients with chronic obstructive pulmonary disease.

OBJECTIVE AND BACKGROUND: The role of COPD self-management plans in improving health outcomes remains unclear. The objective of this study was to assess whether self-management plans administered in primary care have beneficial effects on quality of life, self-care behaviour and health outcomes in the long term for patients with COPD. MATERIAL, PATIENTS AND METHODS: The study was a prospective, unblinded, randomized controlled trial of usual care vs. usual care plus structured education on the use of a written self-management plan and patient-initiated short courses of antibiotics and oral corticosteroids. The study was conducted in general practice, in Christchurch, New Zealand. Participants were 159 patients with COPD randomized by general practice site into control or intervention groups. The primary outcome measure was change in St. George's Respiratory Questionnaire. Secondary variables were frequency of hospital and primary-care attendance, frequency of use of courses of antibiotics and oral corticosteroids over 12 months, and change in Hospital Anxiety and Depression Scale. Self-management knowledge was assessed using a structured interview, the COPD Self-Management Interview. RESULTS: Self-management plans and structured education were associated with higher levels of self-management knowledge at 12 months, but had no effect on change in St. George's Respiratory Questionnaire, health utilization, mental health or self-reported outcomes of patients with COPD managed in general practice. CONCLUSIONS: Self-management knowledge was higher in the intervention group but there was no difference in quality of life or health outcomes due to self-management plans.