Components of the COPD Assessment Test (CAT) associated with a diagnosis of COPD in a random population sample

Abstract

The aim of this study was to determine if components of the COPD Assessment Test (CAT), a validated health status impairment instrument, had additional utility in identifying patients at risk for COPD in whom spirometry testing is appropriate. This study was part of the Canadian Obstructive Lung Disease prevalence study. Consenting participants ≥ 40 years of age were identified by random digit dialing. Smoking history, 8-item CAT scores, and post-bronchodilator spirometry were recorded for each. Stepwise logistic regression analysis was used to identify variables related to the presence of airway obstruction and a final logistic model was developed which best predicted COPD in this sample. Of the 801 individuals approached, 532 were included: 51 (9.6%) had COPD, the majority (92%) of whom fit GOLD I or II severity criteria. Items that correlated significantly with a COPD diagnosis included the CAT total score (p = 0.01) and its breathlessness (p < 0.0001) and phlegm (p = 0.001) components. The final logistic model included: age (<55 or ≥55 years), smoking status (current, former, never) and the CAT breathlessness score (ordinal scale 0–5). The area under the receiver-operating characteristic curve for this model was 0.77, sensitivity was 77.6%, specificity was 64.9% and the positive likelihood ratio was 2.21. In summary, the triad of smoking history, age at least 55 years and the presence of exertional breathlessness were key elements of a simple model which had reliable measurement properties when tested in a random population. This may help identify patients at risk for COPD for whom spirometry testing is recommended.     

Respiratory effects and serum type III procollagen in potato sorters exposed to diatomaceous earth

Exposure to diatomaceous earth with low crystalline silica content (< 1%) is rarely reported to cause pneumoconiotic disease, whereas airway obstruction and bronchitis are more frequently reported. We investigated the occurrence of pneumoconiosis and airflow limitation in 172 male workers from 5 potato sorting plants (55 controls, 29 salesmen, 72 currently exposed, and 16 retired exposed) exposed to inorganic dust from former sea terraces (7.7–15.4 mg/m³), high in diatomaceous earth. The presence of fibrosis was evaluated by chest radiographs (exposed only) and serum levels of type III procollagen (P-III-P) were measured as an estimate of fibrogenetic activity. Lung function was assessed by flow volume curves and impedance measurements. A validated questionnaire was used to record respiratory symptoms. No pneumoconiotic abnormalities were demonstrated by chest radiographs. In line with this finding, serum P-III-P levels were not elevated in exposed workers as compared to controls, suggesting no differences in fibrogenetic activity. In fact, serum P-III-P levels decreased significantly (P < 0.03) with increasing cumulative exposure. Flow volume parameters indicated airflow obstruction, dose-related to (cumulative) dust exposure; the annual decline in forced expiratory flow volume (FEV₁) was estimated at 10.5 m1/year (P < 0.05). Airway obstruction was confirmed by impedance analysis: In the retired group impedance changes were compatible with airway obstruction extending into the peripheral airways. We conclude that this exposure to quartz during potato sorting does not result in an increased risk for pneumoconiosis, but that (prolonged) surveillance in this group is desirable in order to detect early indications of airflow obstruction.     

The combination of tiotropium and budesonide in the treatment of chronic obstructive pulmonary disease

Because additive effects of inhaled corticosteroids and long-acting anticholinergics are unclear, we undertook this study to compare the efficacy of tiotropium alone and tiotropium plus budesonide in patients with chronic obstructive pulmonary disease. The study subjects were randomized to receive either tiotropium 18 microg once daily with or without budesonide 200 microg twice daily for 6 weeks. The efficacy variables were changes in trough forced expiratory volume in one second (FEV1), St. George's Respiratory Questionnaire (SGRQ), 6-minute walk distance (6MWD), and use of rescue medication. One hundred patients were randomized and 81 completed the study. The mean age was 64.0 yr, and the mean FEV1 was 39.7% predicted. Compared with tiotropium alone (N=40), the tiotropium/budesonide combination (N=41) was related to an improvement in the SGRQ total score (tiotropium -2.8 units and tiotropium/budesonide -5.6 units, p=0.003). 6MWD was improved by 13.5 m in the tiotropium group and by 22.5 m in the tiotropium/budesonide group (p=0.031). Changes in trough FEV1 and the use of rescue medication were similar between two groups. In conclusion, compared with tiotropium alone, the tiotropium/budesonide combination was related to an improved health-related quality of life. These data support that low-dose budesonide may enhance the efficacy of tiotropium.     

Reduced pulmonary function is associated with lower levels of endogenous total and free testosterone. The Tromsø Study

Men with chronic obstructive pulmonary disease have reduced endogenous testosterone levels. Little is known, however, about the relationship between pulmonary function and endogenous testosterone levels in a general population. In the present study we have examined the cross-sectional associations between sex hormones measured by immunoassay and pulmonary function assessed with spirometry and oxygen saturation in 2,197 men participating in the fifth Tromsø study. The data were analyzed by univariate correlations, multiple linear regression analyses and analyses of variance and covariance. Total and free testosterone were positively and independently associated with forced vitality capacity, FVC (% of predicted) (P = 0.001 and P = 0.006, respectively) and forced expiratory volume in 1 second, FEV₁ (% predicted) (P = 0.033 and P = 0.002, respectively), and men with severe pulmonary obstruction (FEV₁ % of predicted < 50) had lower free testosterone levels (P = 0.005). In this cross-sectional data from Tromsø, a reduction in pulmonary function was associated with lower levels of total and free testosterone. We suggest that the reduction of total and free testosterone could be due?to an alteration of the hypothalamic-pituitary response.     

Ergospirometry and Echocardiography in Early Stage of Heart Failure with Preserved Ejection Fraction and in Healthy Individuals

Background

Heart failure with preserved ejection fraction is a syndrome characterized by changes in diastolic function; it is more prevalent among the elderly, women, and individuals with systemic hypertension (SH) and diabetes mellitus. However, in its early stages, there are no signs of congestion and it is identified in tests by adverse remodeling, decreased exercise capacity and diastolic dysfunction.

Objective

To compare doppler, echocardiographic (Echo), and cardiopulmonary exercise test (CPET) variables - ergospirometry variables - between two population samples: one of individuals in the early stage of this syndrome, and the other of healthy individuals.

Methods

Twenty eight outpatients diagnosed with heart failure according to Framingham’s criteria, ejection fraction > 50% and diastolic dysfunction according to the european society of cardiology (ESC), and 24 healthy individuals underwent Echo and CPET.

Results

The group of patients showed indexed atrial volume and left ventricular mass as well as E/E’ and ILAV/A´ ratios significantly higher, in addition to a significant reduction in peak oxygen consumption and increased VE/VCO₂ slope, even having similar left ventricular sizes in comparison to those of the sample of healthy individuals.

Conclusion

There are significant differences between the structural and functional variables analyzed by Echo and CPET when comparing two population samples: one of patients in the early stage of heart failure with ejection fraction greater than or equal to 50% and another of healthy individuals.     

Reproducibility and effect of posture on impulse oscillation parameters in persons with spinal cord injury

Background

The impulse oscillation system (IOS) offers significant value in the assessment of airway dynamics in persons with spinal cord injury (SCI) because of minimal patient effort but measurement reproducibility in SCI is unknown.

Objective

To evaluate between-day reproducibility and the effect of posture on airway resistance [respiratory resistances at 5 Hz (R5) and 20 Hz (R20)] in subjects with tetraplegia, paraplegia and able-bodied controls.

Methods

Ten subjects with tetraplegia, 10 subjects with paraplegia and 11 able-bodied individuals were evaluated using IOS. Three 30 second trials were obtained in each while in the seated and supine position on Day 1, and repeated on Day 2.

Results

The within-day coefficient of variation (CV%) for R5 and R20 were comparable in the 3 study groups in the seated and supine positions. Compared to controls, the between-day CV% for the combined data was higher in subjects with tetraplegia and paraplegia for R5 seated, and was higher in subjects with tetraplegia for R5 supine.

Conclusions

IOS has applicability to the study of within-day respiratory resistance in SCI. However, performing longer-term studies in subjects with tetraplegia and paraplegia may be problematic because of the greater variability for R5 when compared to able-bodied individuals.