Impaired bronchodilator response to albuterol in healthy elderly men and women.
BACKGROUND
Lymphocytes of normal elderly subjects and young asthmatics display dysfunctional beta-adrenoceptors. If beta-adrenoceptor dysfunction were found in senescent airways, it might help explain the pathogenesis of late onset asthma.


METHODS
The bronchodilatory effects of albuterol after methacholine-provoked bronchoconstriction were compared in 17 healthy young (age 20 to 36 years) and 17 healthy elderly (age 60 to 76 years) volunteer subjects. Albuterol was inhaled via dosimeter (initially 7.8 micrograms, doubling every 7.5 min) with forced expiratory flow at 50% vital capacity (FEF50) measured prior to each dose. Albuterol sensitivity was expressed as the cumulative logarithm of the area under the FEF50 recovery curve (AUC); a greater AUC meant lower sensitivity. On another study day, spontaneous recovery from methacholine was assessed similarly.


RESULTS
There was no intergroup difference in spontaneous recovery. Despite lower methacholine doses provoking similar (35%) FEF50 falls in elderly subjects, albuterol AUC was greater in elderly subjects (6,552%.min.microgram) than young subjects (3,922%.min microgram; p = 0.03). Multiple regression showed that AUC and age were related (p = 0.02).


CONCLUSIONS
Airway beta 2-adrenoceptor responsiveness is diminished in old age, suggesting that airway beta-adrenoceptor dysfunction may be implicated in late-onset asthma.
Connolly
M J
MJ
Clinical Pharmacology and Gerontology Research Unit, Department of Veterans Affairs Medical Center, Boise, ID 83702, USA.
Crowley
J J
JJ
Charan
N B
NB
Nielson
C P
CP
Vestal
R E
RE
D000328:Adult; D000368:Aged; D000375:Aging / Q000187:drug effects* / Q000502:physiology; D000420:Albuterol / Q000494:pharmacology*; D000704:Analysis of Variance; D001980:Bronchi / Q000187:drug effects* / Q000502:physiology; D001985:Bronchial Provocation Tests / Q000706:statistics & numerical data; D016084:Bronchoconstriction / Q000187:drug effects; D005260:Female; D005540:Forced Expiratory Flow Rates / Q000187:drug effects; D006801:Humans; D008297:Male; D016210:Methacholine Chloride / Q000494:pharmacology; D008875:Middle Aged; D012016:Reference Values; D012044:Regression Analysis; D013997:Time Factors
D016210:Methacholine Chloride; D000420:Albuterol