Bronchodilator efficacy of the fixed combination of ipratropium and albuterol compared to albuterol alone in moderate-to-severe persistent asthma

BACKGROUND: The potential of anticholinergics to provide bronchodilatory benefits over short-acting beta(2)-agonists (SABA) alone in patients with moderate-to-severe persistent asthma has not been well defined. METHODS: An outpatient, randomized, double-blind, single-dose, crossover study in adult asthmatics with moderate-to-severe obstruction despite treatment with inhaled corticosteroids (ICS) was conducted comparing the fixed combination of ipratropium and albuterol (IB+ALB) to albuterol alone (ALB). Serial spirometry was performed over 6h. SABA were withheld for 8h, ICS and LABA for 24h. RESULTS: A total of 113 patients were randomized, 106 completed the study (males n=47; mean+/-SD age=51+/-13 years). Mean+/-SD baseline FEV(1)=1.4+/-0.5 L (49+/-12% predicted). IB+ALB resulted in significantly greater improvements over ALB in the average improvement over baseline in FEV(1) as approximated from the area under the curve from 0 to 6h after drug administration (72 ml, p<0.01) and mean peak FEV(1) response (55 ml, p<0.01) as well as higher FEV(1) responses at individual time points from 0.5 to 6h postdose (p<0.01 for all). Time to onset of response was similar between groups but time to peak and duration of response were longer with IB+ALB versus ALB (120 versus 60 min and 245 versus 106 min, respectively). CONCLUSION: IB+ALB resulted in significantly greater improvement in FEV(1) and longer duration of response compared to ALB alone in patients with moderate-to-severe persistent asthma (Trial number: 1012.50; ClinicalTrial.gov NCT00096616).     

Correlation between heart rate variability and pulmonary function adjusted by confounding factors in healthy adults

The autonomic nervous system maintains homeostasis, which is the state of balance in the body. That balance can be determined simply and noninvasively by evaluating heart rate variability (HRV). However, independently of autonomic control of the heart, HRV can be influenced by other factors, such as respiratory parameters. Little is known about the relationship between HRV and spirometric indices. In this study, our objective was to determine whether HRV correlates with spirometric indices in adults without cardiopulmonary disease, considering the main confounders (e.g., smoking and physical inactivity). In a sample of 119 asymptomatic adults (age 20-80 years), we evaluated forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV₁). We evaluated resting HRV indices within a 5-min window in the middle of a 10-min recording period, thereafter analyzing time and frequency domains. To evaluate daily physical activity, we instructed participants to use a triaxial accelerometer for 7 days. Physical inactivity was defined as <150 min/week of moderate to intense physical activity. We found that FVC and FEV₁, respectively, correlated significantly with the following aspects of the RR interval: standard deviation of the RR intervals (r =0.31 and 0.35), low-frequency component (r =0.38 and 0.40), and Poincaré plot SD2 (r =0.34 and 0.36). Multivariate regression analysis, adjusted for age, sex, smoking, physical inactivity, and cardiovascular risk, identified the SD2 and dyslipidemia as independent predictors of FVC and FEV₁ (R ²=0.125 and 0.180, respectively, for both). We conclude that pulmonary function is influenced by autonomic control of cardiovascular function, independently of the main confounders.     

Electronic clinical records in primary care for estimating disease burden and management. An example of COPD

Chronic obstructive pulmonary disease (COPD) is a significant health problem in developed countries. We aimed to estimate the prevalence of COPD in a single Spanish healthcare area. We also aimed to assess if there are any differences in prevalence and spirometry use among primary care services by utilizing already registered information. We designed a cross-sectional study to determine the prevalence of COPD and the performance of spirometries in each primary care service. A total of 8,444 patients were diagnosed with COPD, with a prevalence of 2.6% for individuals older than 39 years. The prevalence increased with age and was much higher in men. Significant heterogeneity was found in the prevalence of COPD and spirometry use among primary care services. COPD was underdiagnosed and there was wide variability in spirometry use in our area. Greater efforts are needed to diagnose COPD in order to improve its clinical outcomes and to refine registries so that they can be used as reliable sources of information     

Prevalence of obstructive lung disease in HIV population: a cross sectional study

Background

Observational studies have suggested an association between HIV infection and emphysema.

Aims

The primary aim of this study was to estimate the prevalence of obstructive lung disease in HIV-infected patients seen in an outpatient infectious disease clinic. The secondary aim was to estimate the prevalence of Obstructive Lung Disease (OLD) in smokers and non smokers in this population.

Methods

This was a prospective cross-sectional study. Consecutive patients who were seen for routine HIV care underwent spirometry and answered the St. George’s Respiratory Questionnaire (SGRQ). Further, we collected information from the charts on demographics, co-morbidities, CD4 cell count, and HIV viral load (current, baseline, etc).

Results

This study included 98 HIV-infected patients with mean age of 45 years, (SD: 11) and 84% male. They were seen from November 2008 to May 2009 at Thomas Jefferson University in Philadelphia. According to established criteria, spirometry results were classified as normal in 69% and obstructive in 16.3%. Among those who never smoked, the prevalence of obstructive lung disease on spirometry was 13.6%. The prevalence of obstruction in HIV patients with a history of smoking was 18.5%. Current and ever smokers comprised 21.4% and 55% of the patients respectively. The mean SGRQ total score was 7. The mean SGRQ score in active smokers was 17 and 15 in those subjects with a prior history of smoking. The mean SGRQ score among patients with obstruction in spiromerty was 27.7 in patients with obstruction on spirometry.

Conclusion

This urban population of HIV-infected persons has a relatively high prevalence of obstructive lung disease as assessed by spirometry. Furthermore, the high prevalence of obstructive lung disease in never smokers may suggest a possible association between HIV infection and emphysema. In addition the SGRQ total score was comparatively higher in patients with obstruction on spirometry. Our data suggests that potentially all patients with HIV should be screened a for OLD.     

Canadian prediction equations of spirometric lung function for Caucasian adults 20 to 90 years of age: results from the Canadian Obstructive Lung Disease (COLD) study and the Lung Health Canadian Environment (LHCE) study

BACKGROUND:

Currently, no reference or normative values for spirometry based on a randomly selected Canadian population exist.

OBJECTIVE:

The aim of the present analysis was to construct spirometric reference values for Canadian adults 20 to 90 years of age by combining data collected from healthy lifelong nonsmokers in two population-based studies.

METHOD:

Both studies similarly used random population sampling, conducted using validated epidemiological protocols in the Canadian Obstructive Lung Disease study, and the Lung Health Canadian Environment study. Spirometric lung function data were available from 3042 subjects in the COLD study, which was completed in 2009, and from 2571 subjects in the LHCE study completed in 1995. A total of 844 subjects 40 to 90 years of age, and 812 subjects 20 to 44 years of age, were identified as healthy, asymptomatic, lifelong nonsmokers, and provided normative reference values for spirometry. Multiple regression models were constructed separately for Caucasian men and women for the following spirometric parameters: forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC) and FEV₁/FVC ratio, with covariates of height, sex and age. Comparison with published regression equations showed that the best agreement was obtained from data derived from random populations.

RESULTS:

The best-fitting regression models for healthy, never-smoking, asymptomatic European-Canadian men and women 20 to 90 years of age were constructed. When age- and height-corrected FEV₁, FVC and FEV₁/FVC ratio were compared with other spirometry reference studies, mean values were similar, with the closest being derived from population-based studies.

CONCLUSION:

These spirometry reference equations, derived from randomly selected population-based cohorts with stringently monitored lung function measurements, provide data currently lacking in Canada.     

Pitfalls in spirometry: Clinical relevance

Spirometry is one of the functional tests most used in respiratory medicine to assess lung function in health and disease conditions.Its success is grounded on solid principles of lung mechanics that state that maximal flow on expiration is limited by the physical properties of airways and lung parenchyma.In contrast,on inspiration,flow depends on the force generated by the inspiratory muscles.Reduced expiratory forced flow and volumes usually reflect a deviation from health conditions.Yet due to a complex interplay of different obstructive and restrictive lung diseases within the multiple structural dimensions of the respiratory system,flows and volumes do not always perfectly reflect the impact of the disease on lung function.The present review is intended to shed light on a series of artefacts and biological phenomena that may confound the clinical interpretation of the main spirometric measurements.Among them is thoracic gas compression volume,the volume and time history of the inspiratory manoeuvre that precedes the forced expiration,the effects of heterogeneous distribution of the disease across the respiratory system,and the changes in lung elastic recoil.     

Is obesity related to the lung function of non-asthmatic children?

Overweight and obesity are highly prevalent in developed and developing countries among children and adolescents. During the last two decades, it became evident that excess weight is adversely related to respiratory health in childhood and adolescence mainly in terms of asthma occurrence. Additionally, there is a mounting body of evidence that overweight/obesity may also affect lung function in non-asthmatic subjects. The aim of this review was to present and discuss the studies that investigated this issue in non-asthmatic children and adolescents. Only a few studies have evaluated the impact of excess weight on static volumes and their results point towards an inverse relationship between overweight/obesity and functional residual capacity. More studies have been conducted on the impact of excess weight on dynamic lung volumes with inconsistent, however, results. Nevertheless, a relatively consistent finding was that the ratio of forced expiratory volume in 1 s/forced vital capacity was significantly lower among overweight/obese children compared to their counterparts with normal weight. The underlying mechanisms of these observations have not been adequately elucidated but it is believed to result from complex interaction of mechanical, developmental, and metabolic causes. There is a need for more well-designed studies in order to clarify the impact of excess weight on lung function in non-asthmatic subjects, as well as to explore the contribution of factors such as duration and degree of obesity, and fat distribution. Despite the absence of conclusive data, there are still convincing evidence to be communicated to the children and their families as part of the arguments to encourage them to adopt a healthier lifestyle.     

Lower limit of normal based spirometric abnormalities associated with radiographic abnormality in an elderly cohort at low risk for exposure

Background: Although the relation between radiographic abnormalities and spirometric impairment in people with asbestosis has been studied extensively, the extent of spirometric impairment associated with milder radiographic abnormalities is not established.

Objective: To test associations between mild radiographic abnormalities and Lower Limit of Normal (LLN)-based spirometry interpretation.

Methods: Spirometry and CXRs were collected for 1,026 at low risk of exposure to pneumoconiotic agents participants in a medical screening program.

Results: Individuals with each type of isolated or combined International Labour Organization (ILO) abnormalities had up to over sixfold statistically significant increase in odds of LLN-based restrictive pattern physiology (OR = 1.96, 95%CI 1.03–3.73 for parenchymal to OR = 6.09, 95%CI 1.94–19.10 for parenchymal and pleural) compared to those with normal films.

Conclusions: The findings from this study confirm the association of mild profusion abnormalities with clinically relevant, LLN-based lung function abnormalities.