Differences between asthma and COPD in the elderly.

Asthma and chronic obstructive pulmonary disease (COPD) are both characterized by the presence of airflow obstruction. Both diseases are not rare in the elderly population. Distinguishing between these diseases is difficult and may be impossible in some older patients. The aim of the study was to investigate clinical and functional characteristics and the presence of atopic status in elderly subjects compared to COPD patients. Fifty-one patients over 60 years of age were selected for the study (27 patients with late-onset asthma, 24 patients with COPD). Atopy was defined by skin prick test and serum total IgE concentrations which were measured in all patients. Pulmonary function tests including airflow rates, lung volumes, airway resistance, diffusing capacity, and arterial blood gases analysis were performed in all patients. The rate of skin prick test positivity in asthmatics was significantly higher than that of the COPD patients. FEV1 was lower in COPD patients than in asthmatic patients. Bronchial reversibility in asthmatics became significantly higher than in COPD patients. While FRC and RV were increased in both groups showing same degree of pulmonary hyperinflation, patients with COPD demonstrated significantly decreased DLCO when compared to asthmatic patients. The level of both PO2 and PCO2 in patients with COPD significantly differed from asthmatics. In conclusion, a history of heavy smoking, decreased diffusing capacity for carbon monoxide, the presence of more prominent lung hyperinflation and chronic hypoxemia favour the diagnosis of COPD, whereas atopy and significant bronchodilator responsiveness favour the diagnosis of asthma.

Pulmonary function parameters in patients with allergic rhinitis.

Rhinitis patients may have abnormal airway function as demonstrated by an obstruction in large or small airways and increased bronchial reactivity to inhaled nonspecific provocating agents. The nonspecific bronchial hyperreactivity (BHR) is particularly important in patients with rhinitis because they are more prone to develop asthma. However, the factors associated with BHR in rhinitis patients have not yet been explained. Therefore, we performed this study to determine the differences in airflow rates, and bronchial and nasal resistance between nonasthmatic rhinitis patients with or without BHR, and to evaluate the relationship between these parameters and bronchial reactivity to methacholine. A total of 66 patients with allergic rhinitis but not asthma were selected for the study and divided into two groups; Group 1 (40 patients with allergic rhinitis and negative mechacholine provocation test) and Group 2 (26 patients with allergic rhinitis and positive methacholine provocation test). Pulmonary function tests, methacholine provocation tests, anterior rhinomanometry, and skin prick tests were performed on the patients. The study groups were homogeneous with regard to gender, age, duration of illness, and smoking ratio. Expiratory airflow parameters including FVC, FEV1, PEFR, and FEF25 were similar in both groups, however FEV1/FVC, FEF25-75, FEF50, and FEF75 were significantly lower in Group 2. Additionally, sRaw was significantly higher in Group 2 and negatively correlated with the expiratory airflow parameters for small airways. Total nasal resistance was not different between the groups. There was no correlation between nasal resistance and BHR to methacholine or airway resistance. The present study suggests that nonasthmatic rhinitis patients with BHR may have mild but significant changes in the small airways. Clinical and functional follow-up of these patients should assess the long-term consequences of these parameters and their clinical importance.

Distinctive features and long-term survival of reversible and chronic hypercapnic patients with COPD.

Hypercapnic respiratory failure due to chronic obstructive pulmonary disease (COPD) is an indicator of poor prognosis compared to that for normocapnic patients. On the other hand, there exist particular patients who are hypercapnic during an acute exacerbation of COPD but revert to normocapnia after adequate therapy. The aims of this study were: 1) to document the admission characteristics of such patients in terms of clinical and laboratory findings; and 2) to analyse the long-term course and survival of chronic and reversible hypercapnic and normocapnic patients. Fifty-six consecutive patients, admitted with an acute exacerbation of COPD, were enrolled and divided into three groups according to arterial carbon dioxide tension (Pa,CO2) at first admission: 22 chronic hypercapnic (group 1), 15 reversible hypercapnic (group 2) and 19 normocapnic (group 3) patients. Age, sex, smoking history, white blood cell count, serum sodium, potassium, urea and albumin levels and pulmonary function tests at first admission were similar in the three groups. The haematocrit level was significantly higher in group 1 compared with the other groups. Groups 1 and 2 had lower pH, arterial oxygen tension (Pa,O2) and arterial oxygen saturation (Sa,O2) and a higher Pa,CO2 than group 3. The Pa,CO2 was also higher in group 1 than in group 2. The presence of cor pulmonale was significantly higher in group 1 compared with groups 2 and 3 (81.8 versus 60 and 10.5%, respectively). During the follow-up period, a significant increase was observed in airway obstruction associated with progressive hypercapnia and hypoxaemia in chronic hypercapnic patients, and 12 of 15 (80%) reversible hypercapnic patients progressed to a chronic hypercapnic status. The survival analyses after 10 yrs of follow-up revealed comparable survival durations in chronic and reversible hypercapnic patients (median of 8.86 versus 9.52 yrs, p > 0.05). In conclusion, despite careful monitoring of particular characteristics in chronic and reversible hypercapnic patients at the time of admission, no long-term predictivity of these features for either the course of the disease or survival could be found.

Effect of pretreatment with heparin on pulmonary and cutaneous response.

Although anticoagulant properties of glycosaminoglycan heparin are primary in medicine, a variety of other biological functions related to heparin have been suggested. Since heparin is a selective inhibitor of inositol triphosphate (IP3) receptors that are involved in release of calcium in mast cells and many other cells, it is possible that heparin may act as a natural anti-inflammatory molecule and modify these reactions. Therefore, the purpose of the present study was to determine the role of heparin in allergic inflammatory responses: the pulmonary reaction and the cutaneous response, in a double-blind, placebo-controlled, crossover randomized trial. To evaluate the effect of heparin on methacholine-induced bronchoconstriction, nebulized heparin (20,000 units) was administered to 12 asthmatics and nonspecific challenge was performed immediately thereafter. Measurements of Raw and SGaw were obtained before and 1 hr after nebulization of heparin. In 12 other allergic subjects, heparin (25 U/kg) was given intravenously 10 min before skin prick test. We demonstrated that pretreatment with heparin reduced skin test reactivity from 24.06 +/- 1.2 mm to 18.26 +/- 2.27 mm and increased the methacholine PC20 value from 1.69 +/- 0.48 mg/ml to 8.14 +/- 3.11 mg/ml (p < 0.05), but did not prevent an increase in Raw and/or a decrease in SGaw. Heparin modified the methacholine-induced bronchoconstrictor response, but this did not reflect a protective effect in airway resistance and specific conductance. These data suggest that anti-inflammatory effects of heparin are time-dependent and/or that heparin may have a transient inhibitory role in allergic reactions.