AGE-DEPENDENT EFFECT OF ORAL GLUCOCORTICOIDS ON MARKERS OF BONE-RESORPTION IN PATIENTS WITH ACUTE ASTHMA

It is generally accepted that bone formation is depressed during corti costeroid treatment, but the effects of glucocorticoids on bone resorp tion are less well characterized. We have investigated the effects of short-term treatment with high-dose oral glucocorticoids on biochemica l markers of bone turnover in 20 consecutive patients with asthma who sought help for acute respiratory obstruction in our emergency departm ent. Serum concentrations of the carboxy-terminal cross-linked telopep tide of type 1 collagen (1CTP), reflecting bone resorption, and the ca rboxyterminal propeptide of type 1 procollagen (P1CP), reflecting bone formation, were measured by radioimmunoassay. Changes of the circulat ing levels of the bone resorption marker 1CTP after treatment were age dependent with a significant negative correlation (r = -0.54, P = 0.0 1). The dependency on age remained when correcting, in a multiple line ar regression analysis, for 1CTP levels at admission, weight, sex, and daily maintenance dose of inhaled glucocorticoids. Circulating levels of P1CP were suppressed in the whole group 1 week after initiation of glucocorticoid therapy, from 123.3 +/- 10.2 ng/ml at admission to 88. 1 +/- 6.3 ng/ml after 1 week (P < 0.01). The changes in P1CP levels we re not related to age. Our data indicate that bone formation is suppre ssed by glucocorticoids in all age groups, whereas the effect of gluco corticoids on markers of bone resorption is dependent on age.