Influência da idade e da obstrução brônquica na resposta broncodilatadora em idosos.

Resumo

Bronchodilator response may be influenced by airway flow limitation, age and genetics. Evidence has shown that this response increases with higher levels of airway obstruction and is altered with age and presence of specific genetic polymorphisms of the β2 adrenergic receptors.Correlate the airway flow limitation (FEV1, FVC, IC, RV) with the bronchodilation response, to β-adrenergics (salbutamol (s)) and to anticholinergics (ipratropium bromide (b)), in a group of elderly people with diagnosed asthma.We submitted a group of twelve aged individuals (>65Y), with diagnosed asthma, to a basal ventilatory lung function evaluation, followed by a bronchodilation test, in two consecutive days (in one day using s, in the other using b). They were submitted to a functional ventilatory evaluation followed by a bronchodilator test (one day with s, other day with b). The individuals were in a stable period, without anti-asthmatic medication in the previous 24 hours. Plethismography and spirometry followed ATS/ERS 2005 criteria. Statistic analysis used SPSS for Windows. Correlations were established using the Pearson coefficient (r value).The bronchodilation response after b correlated best, with basal ventilatory evaluated parameters, than bronchodilation response after. - The FEV1 response increased as lower were the basal IC/TLC values, only after b; - The FVC response was increased as lower were the basal IC/TLC values and as higher were basal RV/TLC values, only after b; - The IC/TLC response increased as lower were basal IC/TLC values, only after b; - For both b and s, the RV/TLC responses increased as lower were basal VR/TLC values.The found correlations point out the relation of increased airway flow limitation and better bronchodilation response to b, which assumed importance to the responses related with the RV basal variation. The responses to s didn't show such a grade of dependence. That might be explained by the probable concurrence of other variables for the grade of bronchodilation response to the β-adrenergics. The existence of genetic polymorphisms of ADRB2 gene, already described in the literature, show an increasing in bronchodilation response of Arg/Arg homozygotes when β-adrenergic therapeutic is replaced for the anticholinergic one.