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.

Inhaled and systemic corticosteroid therapies: Do they contribute to inspiratory muscle weakness in asthma?

BACKGROUND: Patients with asthma incur the risk of steroid-induced myopathy, which is a well-known side effect of treatment with corticosteroids. However, the adverse effect of long-term steroid treatment on respiratory muscle function remains controversial. OBJECTIVE: We aimed to evaluate the effects of long-term moderate dose of systemic corticosteroids and high-dose inhaled beclomethasone on maximal inspiratory and expiratory pressures (PImax and PEmax, respectively) in two groups of asthmatic patients exhibiting comparable levels of hyperinflation. METHODS: Twelve steroid-dependent asthmatic patients requiring 10-20 mg/day of prednisone-equivalent corticosteroids for an average of 9.83 +/- (SD) 9.86 years; 14 subjects with moderate to severe asthma who have used inhaled beclomethasone for at least 1 year at a daily dose higher than 1,000 microg and 15 healthy controls were included to the study. RESULTS: No significant difference in pulmonary function tests and arterial blood gases appeared between two asthmatic groups with different treatment modalities. PImax as an absolute value was significantly lower in steroid-dependent asthmatics than in patients treated with inhaled beclomethasone and controls (p < 0.01). %PImax was also lower in steroid-dependent asthmatics than in control groups (p < 0.01). A significant correlation was found between %PImax and hyperinflation assessed by %RV, %FRC, %FRC/TLC (p < 0.05) in all asthmatic patients. CONCLUSIONS: We believe that hyperinflation plays a major role in inspiratory muscle dysfunction in asthma, but the finding of significantly decreased PImax values in steroid-dependent asthmatics when compared with patients on high-dose inhaled beclomethasone with a comparable level of hyperinflation points to a deleterious effect of long-term, moderate-dose systemic corticosteroid but not high-dose beclomethasone on inspiratory muscle function in asthmatics.