Zara Pogson

Risk of community-acquired pneumonia and the use of statins, ace inhibitors and gastric acid suppressants: a population-based case-control study.

Previous studies have shown that treatment with gastric acid suppressants may be associated with an increased risk of pneumonia whilst the use of statins and ACE inhibitors (ACEI) may decrease the risk of acquiring pneumonia. The evidence is conflicting however. Our aim was to investigate the effect of these drugs on pneumonia using population‐based data from the UK.

The impact of statins, ACE inhibitors and gastric acid suppressants on pneumonia mortality in a UK general practice population cohort.

Pneumonia is a common diagnosis in general practice in the United Kingdom. Previous studies suggest that commonly prescribed drugs in general practice may influence pneumonia mortality.

Does a Low Sodium Diet Improve Asthma Control? A Randomized Controlled Trial

RATIONALE Observational studies and initial randomized trials have indicated that a low sodium diet may improve asthma control. OBJECTIVES We tested the hypothesis that a low sodium diet would improve asthma control over a 6-week period. METHODS Participants with a physician diagnosis of asthma and measurable bronchial reactivity to methacholine entered a randomized double-blind placebo-controlled trial. All adopted a low sodium diet and were randomized to receive either 80 mmol/day of oral sodium supplements (normal sodium intake) or matched placebo (low sodium intake) for 6 weeks. The primary outcome was change in bronchial reactivity to methacholine; secondary outcomes were change in lung function, morning and evening peak expiratory flow, asthma symptoms score, daily bronchodilator use, Juniper Standardized Asthma Quality of Life Questionnaire score, and atopy. MEASUREMENTS AND MAIN RESULTS A total of 220 individuals entered the study, of whom 199 completed the protocol. In the low sodium-intake group, mean daily urinary sodium excretion decreased by 20 mmol (SD, 64 mmol) and in the normal-sodium-intake group increased by 28 mmol (SD, 74 mmol). There were no differences between the two groups in the primary or secondary outcome measures; the mean difference in bronchial reactivity between the low- and normal-intake groups was -0.03 doubling doses of methacholine (95% confidence interval, -0.60 to 0.53). CONCLUSIONS The use of a low sodium diet as an adjunctive therapy to normal treatment has no additional therapeutic benefit in adults with asthma and bronchial reactivity to methacholine.

The incidence of pneumonia using data from a computerized general practice database

Despite being widely recognized as a significant public health problem there are surprisingly few contemporary data available on the incidence of pneumonia in the UK. We conducted a general population-based cohort study to determine the incidence of pneumonia in general practice in the United Kingdom. Data were obtained from The Health Improvement Network (THIN) - a computerized, longitudinal, general practice database. Recorded diagnoses of pneumonia between 1991 and 2003 were used to calculate the incidence of pneumonia stratified by year, sex, age group and deprivation score. The overall incidence of pneumonia was 233/100 000 person-years [95% confidence interval (CI) 231-235] and this rate was stable between 1991 and 2003. The incidence of pneumonia was slightly lower in females compared to males [age-adjusted incidence rate ratio (IRR) 0.88, 95% CI 0.86-0.89]. Pneumonia was most common in children aged <4 years and adults aged >65 years. There was an increased incidence of pneumonia with higher levels of socioeconomic disadvantage such that people living in the most deprived areas of the United Kingdom were 28% more likely to get pneumonia than those in the least deprived areas (age- and gender-adjusted IRR 1.28, 95% CI 1.24-1.32). In conclusion, pneumonia is an important public health problem and the incidence of pneumonia is higher in people at the extremes of age, men and people living in socially deprived areas.

Pneumonia mortality in a UK general practice population cohort

BACKGROUND Pneumonia is a common diagnosis in general practice in the United Kingdom and yet there is little known about the short- and long-term prognosis of people with a diagnosis of pneumonia in general practice. We investigated the short- and long-term survival of people with pneumonia diagnosed in general practice as compared to the general population for all ages. METHODS This was a general population-based cohort study. Data was obtained from a comprehensive general practice database called The Health Improvement Network (THIN) database which has computerized medical records from 300 general practice surgeries in the United Kingdom. We used Cox regression for our analyses. RESULTS For pneumonia cases the 30-day mortality was 18.5% and the 3-year mortality was 30.8%. The equivalent figures for the general population controls were 0.4% and 10.3% respectively. The adjusted hazard ratio (HR) for all-cause mortality (for total follow-up time) in pneumonia cases vs. general population was 4.64 (95% CI 4.35-4.95). For the first 30 days the risk of mortality in cases was 46 times more (adj. HR 45.90, 95% CI 36.80-55.20). Even in the period of follow-up 91 days after diagnosis cases were almost 20% more likely to die compared to general population (adj. HR 1.19, 95% CI 1.08-1.31). CONCLUSION People in general practice who have a diagnosis of pneumonia have a markedly increased mortality in the short-term but some increase in mortality persists during longer-term follow-up.

The association between serum osmolality and lung function among adults

The extensive pulmonary vasculature results in the lungs being intimately exposed to circulating blood. As increased serum osmolality may be associated with an increase in pro-inflammatory activity, this has the potential to result in damage to the lungs and reduced lung function. The objective of the present study was to test the hypothesis that increased serum osmolality is associated with a lower forced expiratory volume in one second (FEV1) and forced vital capacity (FVC). The present study was a cross-sectional study of 10,602 participants in the Third National Health and Nutrition Examination Survey aged ≥17 yrs for whom there were adequate data on all outcomes and exposures. After adjustment for age, smoking and other confounding factors, increased serum osmolality was inversely associated with both FEV1 and FVC. An increase of 1 sd in serum osmolality was associated with a decrease in both FEV1 of 19.8 mL and FVC of 35.3 mL. The constituent assays demonstrated a complex relationship with both FEV1 and FVC. Increased serum osmolality was associated with decreased forced expiratory volume in one second and forced vital capacity. If causal, this may have implications for the understanding of the processes that are involved in the pathophysiology of decline in lung function.

Exhaled Carbon Monoxide in Asthmatic Adults with Bronchial Reactivity: A Prospective Study

Hypothesis. We hypothesized that eCO may permit non-invasive assessment of disease activity in adults with asthma and bronchial reactivity. Methods. A total of 209 participants 18 to 65 years of age with a diagnosis of asthma and bronchial reactivity provided data for analysis. The association between eCO and bronchial reactivity, forced expiratory volume in one second (FEV1), forced vital capacity (FVC), peak expiratory flow rate measurements (PEFR), asthma symptoms score, and bronchodilator use cross-sectionally and within-subject change in eCO were analyzed in relation to change in these variables over 6 weeks. Results. There was no difference in eCO in those who were taking inhaled corticosteroids and those who were not (p = 0.33). There was also no cross-sectional or within-in subject association between eCO and bronchial reactivity, FEV1, FVC, PEFR, symptoms score, or bronchodilator use. Conclusions. In a population of adults with bronchial reactivity, eCO has no or very limited potential as a biomarker of asthma activity.

Does a low sodium diet modify heart rate variability? A randomised placebo-controlled double-blind trial

BACKGROUND Increased heart rate variability (HRV) is associated with a low risk of mortality, as is consuming a low sodium diet. As the survival benefits of a low sodium diet may be mediated partly by an increase in HRV, we have tested the hypothesis that adopting a low sodium diet increases HRV. METHODS We used a randomised double-blind placebo-controlled trial design. Participants were aged 18-65 years old, had a physician diagnosis of asthma. All adopted a low sodium diet and they were randomised to receive either 80 mmol/day of oral sodium supplements (normal sodium intake - NSI) or matched placebo (low sodium intake-LSI) for 6 weeks. The primary outcome was change in SDNN (standard deviation of the N-N intervals); secondary outcomes were changes in other time domain and frequency domain measures of HRV. RESULTS In those allocated to the LSI, mean daily urinary sodium excretion decreased by 22 mmol; and in those allocated to the NSI mean daily urinary sodium excretion increased by 31 mmol. There were no differences between the two groups for either the primary or secondary outcome measures. The mean difference in change in SDNN between those who received the LSI compared to the NSI was -2.7 ms (95% Confidence Intervals CI; -18.0 to +12.6). CONCLUSIONS Adopting a low sodium diet does not have an impact on SDNN over a 6 weeks period. Future studies should aim to achieve a larger change in dietary sodium intake for a longer duration than 6 weeks.

An Evaluation of the Use of Bronchoconstriction Induced by Deep Inspiration as a New Epidemiological Measure for Asthma

Rationale. Bronchoconstriction after deep inhalation is associated with increased severity of asthma and is also a predictor of length of hospital stay in individuals admitted with asthma exacerbations. We hypothesized that this effect may represent a new non-invasive method to assess bronchial reactivity and other measures of asthma control. Methods. We used a cross-sectional study design recruiting participants 18 to 65 years of age with a physician diagnosis of asthma. All participants were asked to provide three serial peak expiratory flow rate (PEFR) measurements in the morning, and bronchial reactivity was measured up to a maximum inhaled dose of 24.5 μ moL methacholine on the same day. Participants also recorded their asthma symptoms score and bronchodilator use during the 7 days before measuring bronchial reactivity. Results. A total of 127 people provided data for analysis. There was no significant relationship between bronchoconstriction after deep inhalation (as measured by three serial PEFR measurements) and either bronchial reactivity to methacholine, asthma symptoms, or bronchodilator use. Conclusions. Bronchoconstriction induced by deep inspiration does not appear to be a valid marker of airway hyperresponsiveness or asthma severity in adults with mild to moderate asthma.