Body mass index, airflow obstruction and dyspnea and body mass index, airflow obstruction, dyspnea scores, age and pack years-predictive properties of new multidimensional prognostic indices of chronic obstructive pulmonary disease in primary care.

BACKGROUND: The assessment of the severity of chronic obstructive pulmonary disease (COPD) should involve a multidimensional approach that is now clearly shown to be better than using spirometric impairment alone. The aim of this study is to validate and compare novel tools without an exercise test and to extend prognostic value to patients with less severe impairment of Forced expiratory volume 1 s. METHODS: A prospective, observational, primary care cohort study identified 458 eligible patients recruited from the primary care clinics in the northeast of England in 1999-2002. A new prognostic indicator - body mass index, airflow obstruction and dyspnea (BOD) together with the conventional prognostic indices age, dyspnea and airflow obstruction (ADO), global initiative for chronic obstructive lung disease (GOLD) and new GOLD matrix were studied. We also sought to improve prognostication of BOD by adding age (A) and smoking history as pack years (S) to validate BODS (BOD with smoking history) and BODAS (BOD with smoking history and age) as prognostic tools and the predictive power of each was analyzed. RESULTS: The survival of the 458 patients was assessed after a median of 10 years when the mortality was found to be 33.6%. The novel indices BOD, BODS, and BODAS were significantly predictive for all-cause mortality in our cohort. Furthermore with ROC analysis the C statistics for BOD, BODS, and BODAS were 0.62, 0.66, and 0.72, respectively (P < 0.001 for each), whereas ADO and GOLD stages had a C statistic of 0.70 (P < 0.001) and 0.56 (P < 0.02), respectively. GOLD Matrix was not significant in this cohort. CONCLUSION: BOD, BODS, and BODAS scores are validated predictors of all-cause mortality in a primary care cohort with COPD.

Precision in Diagnosing and Classifying COPD: Comparison of Historical Height with Current Height and Arm Span to Predict FEV(1).

BACKGROUND: Measured reductions in lung function, as a result of COPD, use a measured current value and make comparisons to a determined 'normal' value arrived at using a regression equation based upon a patients height. Osteoporosis is a recognised co-morbidity in patients with chronic obstructive pulmonary disease (COPD) and may cause excessive height loss resulting in the 'normal' values and disease progression being under-estimated. PURPOSE: The aim of the study was to examine the height variation in a cohort of COPD patients and controls over a 7-8 years period and evaluate its impact on estimates of lung function and hence COPD progression. METHODS: In 1999-2002 we studied a cohort of primary care patients in Sunderland, UK with and without COPD and reexamined 104 (56 male) during 2007-2009. We calculated FEV(1)% predicted for actual and estimated height (armspan/1.03 and armspan/1.01 in males and females respectively). RESULTS: In 1999-2002 the subjects were aged 62.6 ± 9.4 years, BMI was 26.4± 4.7 kg/m2, predicted FEV(1) was 59.0 ±16.0, and mean actual height was 167.3±8.9cm. The actual height changed significantly (p<0.001) by 2cms over time in both genders. Whilst the overall classifications of the cohort did not change significantly when armspan was used to determine height and hence normal lung volume, individual cases did move to a classification of higher severity. CONCLUSIONS: The study suggests that current measured height may underestimate the degree of impairment of FEV(1) and hence progression of COPD. The use of height, derived from armspan, may give a more accurate measure of 'normal' lung volumes and hence the degree of impairment.

Muscle weakness, health status and frequency of exacerbations in chronic obstructive pulmonary disease.

BACKGROUND: Multiple factors contribute to muscle weakness and reduced muscle mass in chronic obstructive pulmonary disease (COPD) and this impacts patients' quality of life. One factor implicated in this process is systemic inflammation, an accompaniment of acute exacerbations. Recurrent exacerbations are associated with lower health status. This study examines the relationship between muscle weaknesses, health status and exacerbation frequency in a cohort of patients with COPD. METHODS: This is an observational study of 188 (95 female) patients with COPD attending two hospital clinics in the northeast of England between 2004 and 2007. We measured spirometry, body mass index, health status (St George's Respiratory Questionnaire) and grip strength and recorded Medical Research Council dyspnoea scores and the frequency of exacerbations in the previous year. RESULTS: Patients were aged 72.5±8.3 years (data expressed as mean±SD) with Medical Research Council score of 3.6±0.8, forced expiratory volume in one second (FEV(1)) of 49.2±21.5 per cent predicted and a total St George's Respiratory Questionnaire score of 72.2±15.5. Grip strength, expressed as per cent predicted, was 72.0±21.8 in men and 81.0±18.2 in women. Exacerbations ranged from zero to five in the previous year and there were associations of reduced grip strength with exacerbation frequency (χ(2)=9.634; p=0.0019) and lower health status (χ(2)=34.00; p<0.001). CONCLUSION: Our data clearly demonstrate that reduction in grip strength occurs more frequently and to a greater extent in patients with a history of frequent exacerbations and is associated with reduced health status.

Ventilation and perfusion lung scintigraphy of allergen-induced airway responses in atopic asthmatic subjects.

BACKGROUND: Both ventilation (V) and perfusion (Q) of the lungs are altered in asthma, but their relationships with allergen-induced airway responses and gas exchange are not well described. METHODS: The effects of aerosolized allergen provocation of V/Q abnormalities in nonsmoking, male atopic asthmatics (six dual responders and two isolated early responders) were compared with measurements of airflow limitation (forced expiratory volume in 1 s [FEV(1)]), gas exchange (arterial oxygen saturation, arterial oxygen partial pressure and alveolar-arterial oxygen gradient) and airway reactivity (provocative concentration of histamine causing a decrease of 20% in FEV(1)). V and Q lung scans at 30 min and 6 h following allergen challenge and changes in all variables were compared with prechallenge data. Digital image data were registered to baseline scans, and quantitative comparisons of changes made were supported by qualitative assessments of the images. RESULTS: All subjects showed evidence of impaired gas exchange, as reflected by lowered arterial oxygen tension and widened alveolar arterial oxygen gradients. Baseline V/Q scans were abnormal, and there were allergen-induced changes in V and Q at 30 min, with scans at 6 h showing additional changes in Q, particularly in dual responders. Allergen-induced gas trapping was evident at 30 min and was sustained at 6 h. CONCLUSIONS: Regional patterns of V and Q derived from lung scintigraphy showed a wider range of disturbances than were indicated by the magnitude of airflow limitation and arterial hypoxemia following allergen provocation, and they remained abnormal despite normalization of FEV(1). Imaging of regional abnormalities of gas exchange may be relevant in the evaluation of patients with asthma.