Am. J. Respir. Crit. Care Med., Vol 149, No. 3, 03 1994, 667-672.
Relationship of plasma epinephrine and circulating eosinophils to nocturnal asthma
ME Bates, M Clayton, W Calhoun, N Jarjour, L Schrader, K Geiger, T Schultz, J Sedgwick, C Swenson and W Busse
Department of Medicine, University of Wisconsin, Madison.
The mechanisms of nighttime airway obstruction are not fully established,
but include circadian fluctuations in epinephrine and cortisol. To evaluate
the relationship of circadian patterns in epinephrine and cortisol to
nighttime airflow obstruction, 10 young adult asthma patients (ages 19 to
25 yr) were admitted to a hospital clinical research unit for a 3-day study
during which plasma concentrations of epinephrine, cortisol, and histamine
were determined along with white blood cell and eosinophil counts every 6 h
(1600, 2200, 0400, and 1000 h). Six of the 10 patients experienced at least
one episode of nocturnal asthma (defined by more than a 15% decrease in
antemeridian (A.M.) to postmeridian (P.M.) FEV1 values). Plasma epinephrine
levels (pg/ml) showed a circadian pattern, and the concentration at 2200 h
was significantly (p = 0.039) different for the nocturnal and non-nocturnal
asthma groups. Circulating eosinophil numbers were greater in subjects who
had more frequent episodes of nocturnal asthma, and correlated with the
frequency of nocturnal asthma (r = 0.732, p = 0.02, Spearman rank
correlation) and average percent decrease in FEV1 (r = 0.667, p = 0.035).
Plasma cortisol concentrations also showed circadian patterns, but no
direct association with nocturnal asthma; plasma histamine concentrations
showed no circadian patterns and no association with nocturnal asthma. Our
findings indicate that changes in plasma epinephrine precede the
development of nocturnal airway obstruction and contribute to the
likelihood of nighttime airflow obstruction.
