Serum cortisol levels in patients with bronchial asthma. Relationship to glucocorticoid therapy and patient age.

Serum cortisol levels were examined in 94 patients with bronchial asthma in relation to dose of glucocorticoids and age. 1. The level of serum cortisol was significantly lower in group A patients, treated with glucocorticoids (prednisolone of 5mg/day or more) for more than 2 years, (2.4±1.2mcg/㎗) than in group B, treated with glucocorticoids (prednisolone of 5mg or less) for less than 2 years, (6.8±3.7mcg/㎗) (p<0.001) and in group C, treated without glucocorticoids, (12.6±3.9mcg/㎗) (p<0.001). The serum cortisol level was also significantly lower in group B than in group C (p<0.001). 2. The level of serum cortisol was significantly lower in patients over the age of 70 compared to that in those aged between 0 and 39 years (p<0.01) and those between 40 and 49 (p<0.05), and those between 50 and 59 (p<0.02). The level was also lower in patients between 60 and 69 compared to that in those between 0 and 39, however, this was not significant. These results demonstrate that the level of serum cortisol decreases by long-term glucocorticoid regimen and with aging.