Gastro-oesophageal reflux and respiratory symptoms in Busselton adults: the effects of bodyweight and sleep apnoea.

BACKGROUND/AIM: Respiratory symptoms and gastro-oesophageal reflux disease (GORD) are common within the general population. Although a number of epidemiological studies have addressed their relationship, none has investigated the confounding effects of body mass index (BMI) and obstructive sleep apnoea (OSA), both of which are associated with reflux. METHODS: Men and women (2700) from the 2005-2007 cross-sectional Busselton health survey were included. Questionnaire data included demography, information on general health, asthma, cough, wheeze, dyspnoea and reflux symptoms (never, monthly or less often and weekly or more often). BMI, risk of OSA (Berlin questionnaire definition), spirometry and airway hyperresponsiveness (AHR) were recorded. The effects of BMI and OSA on the relationship between respiratory and reflux symptoms were examined using logistic regression models, expressed as adjusted odds ratios for risk of respiratory symptoms by reflux symptom category. RESULTS: Fifty per cent had reflux symptoms (5-10% weekly or more often). Reflux symptoms had strong positive, dose-related associations with cough/phlegm, breathlessness, chest tightness and wheeze in the last 12 months (P < 0.001), but were not related to diagnosed asthma or AHR. Twenty-three per cent were at high risk of OSA and 63% had a BMI of >25 (22% > 30). Increased weight or high risk of OSA did not affect the relationship between respiratory symptoms and reflux symptoms. CONCLUSION: The relationship between reflux and respiratory symptoms was independent of BMI, high risk of OSA or AHR. These findings suggest that reflux contributes directly to respiratory symptoms.

Patterns of airway disease and the clinical diagnosis of asthma in the Busselton population.

The aim of this study was to examine how objective measures related to lung function cluster in the general population and how the patterns relate to asthma and bronchitis as diagnosed by a doctor (DDA and DDB, respectively). A cross-sectional survey of an age-stratified random general population sample of 1,969 adults from the electoral register of Busselton (Australia) was performed in 2005-2007. Respiratory symptoms, DDA ever, DDB ever, recent wheezing and smoking history, together with anthropometric measurements, forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC), methacholine challenge or bronchodilator response, exhaled nitric oxide (eNO), skin-prick tests to common allergens, and blood eosinophil and neutrophil counts were studied. Cluster analysis (variables sex, age, atopy, FEV1 % predicted, FEV1/FVC, airway hyperresponsiveness, eNO, log eosinphil count, log neutrophil count and body mass index) was used to identify phenotypic patterns. Seven clusters (subjects with DDA and DDB, respectively) were identified: normal males (n=467; 7 and 13%), normal females (n=477; 12 and 18%), obese females (n=250; 16 and 28%), atopic younger adults (n=330; 21 and 17%), atopic adults with high eNO (n=130; 30 and 25%), atopic males with reduced FEV1 (n=103; 33 and 32%) and atopic adults with bronchial hyperreactivity (n=212; 40 and 26%). The clinical diagnosis of asthma (ever) and bronchitis (ever) is not specific for any of the clustering patterns of airway abnormality.

Clostridioides difficile colonization and infection in a cohort of Australian adults with cystic fibrosis.

BACKGROUND: Little is known about Clostridioides difficile infection (CDI) in patients with cystic fibrosis (CF). The aim of this study was to investigate the prevalence, molecular epidemiology and risk factors for CDI in asymptomatic and symptomatic adults with CF in Western Australia. METHODS: Faecal samples from symptomatic and asymptomatic patients were prospectively collected and tested for the presence of C. difficile by toxigenic culture. Ribotyping was performed by established protocols. Logistic regression analysis was performed to analyse the risk factors for C. difficile colonization and infection. Extensive environmental sampling was performed within the CF clinic in Perth. RESULTS: The prevalence rates of asymptomatic toxigenic and non-toxigenic C. difficile colonization were 30% (14/46 patients) and 24% (11/46 patients), respectively. Fifteen ribotypes (RTs) of C. difficile were identified, of which non-toxigenic RT 039 was the most common. Among the symptomatic patients, the prevalence of toxigenic CDI was 33% (11/33 patients). Impaired glucose tolerance/diabetes mellitus and duration of intravenous antibiotic use in the past 12 months were significantly associated with increased risk of asymptomatic toxigenic C. difficile carriage and CDI. A trend towards higher CF transmembrane conductance regulator modulator treatment was observed in the CDI group. Extensive environmental sampling showed no evidence of toxigenic C. difficile contamination within the CF clinic. CONCLUSIONS: A high prevalence of asymptomatic carriage of toxigenic C. difficile was observed in adults with CF, comparable with that observed in the symptomatic CF population. There was no evidence of direct person-to-person transmission.

Population based epidemiology and prognosis of mesothelioma in Leeds, UK.

INTRODUCTION: Malignant mesothelioma is a fatal neoplasm, which is rapidly increasing in incidence throughout Western Europe. To date there have been no studies reporting on the natural history and interventional practices on a comprehensive unselected population, as opposed to reports from referral institutions or compensation claimants. We present a population based study capturing data on all patients with mesothelioma presenting within a defined geographical area over a 4 year period in the UK. METHOD: Data of all cases occurring in Leeds with a population of 750 000 were collected retrospectively from 2002 to 2003 and prospectively from 2004 to 2005. All patients' hospital records and the Trust histology database were reviewed, as well as coroner's reports on all patients with a post mortem diagnosis of mesothelioma. RESULTS: Over the 4 year study period, there were a total of 146 cases in Leeds; 77% were male. Median age was 74 years (range 36-93). Median survival from diagnosis was 8.9 months. 92% and 8% had histological or cytological confirmation, respectively. 85% had documented evidence of definite or probable exposure to asbestos. 110/146 (75%) had symptomatic pleural effusions at presentation. Twice the number of patients (42 vs 17) were managed with surgical rather than bedside pleurodesis and these had a lower recurrence rate (14% vs 47%; p = 0.02). 122 patients had video assisted thoracoscopic surgery/cutting CT biopsies or chest drains. 73/122 (60%) had prophylactic radiotherapy to these sites. There were seven cases (5%) of tract invasion by tumour and six of these had received prophylactic radiotherapy. Median time to seeding was 174 days. 92/146 (63%) had a performance status of 2 or better at diagnosis but only 54/146 were considered fit for chemotherapy. Of these, 28 (52%) declined chemotherapy; the overall uptake of chemotherapy or entry into a trial was 18%. No patient had radical surgery. CONCLUSION: This comprehensive population based audit has shown that the median age at presentation of malignant mesothelioma is increasing and baseline performance status and survival is worse than in selected series. 37% of patients were considered suitable for palliative chemotherapy but less than 20% accepted this offer. Thorascopic pleurodesis appears to be associated with fewer recurrences. The role of prophylactic radiotherapy to chest drain and biopsy sites needs reappraisal.

Exhaled breath condensate pH and exhaled nitric oxide in allergic asthma and in cystic fibrosis.

BACKGROUND: It has been proposed that the pH of airway lining fluid may regulate the fractional exhaled concentration of nitric oxide (Fe(NO)) in respiratory disease. METHODS: Fe(NO), exhaled breath condensate (EBC) pH, and EBC concentrations of nitrite plus nitrate (NO2/NO3) were compared in 12 subjects with stable asthma, 18 with stable cystic fibrosis (CF), and 15 healthy control subjects. Eight of the CF patients were studied on a separate occasion at the start of a pulmonary exacerbation. RESULTS: Fe(NO) was significantly greater in asthmatic subjects than in control subjects (mean 35 v 9 ppb, p<0.001). EBC pH, however, was similar in the asthmatic and control groups (median 5.82 v 6.08, p=0.23). Levels of NO2/NO3 were on average higher in EBC samples from asthmatic subjects, but the difference was not significant. In patients with stable CF both the Fe(NO) (mean 4 ppb, p<0.001) and EBC pH (median 5.77, p=0.003) were lower than in the control group. Levels of EBC NO2/NO3 (median 29.9 microM; p=0.002) in patients with stable CF, in contrast, were significantly higher than in control subjects. During CF exacerbations, EBC pH was further reduced (median 5.30, p=0.017) but Fe(NO) and NO2/NO3 were unchanged. CONCLUSIONS: These findings demonstrate a dissociation between EBC pH and Fe(NO) in inflammatory airways disease.