Tratamento prolongado com corticosteróide inalado e o metabolismo ósseo em crianças com asma persistente Long-term treatment with inhaled corticosteroids and bone metabolism in children with persistent asthma

Objectives: to evaluate the interference of long-term treat- ment with inhaled corticosteroids (IC) in children with persis- tent asthma followed in a specialized clinic Patients and Methods: 34 children (4 to 14 years of age, 17 males) with moderate or severe persistent asthma, followed as outpatients in a specialized clinic were admitted in the stu- dy. All of them have been treated with IC for at least one year. They were evaluated by anamnesis (age of onset of symptoms, asthma severity, personal and familiar history of atopic disea- se, type and cumulative intake of corticosteroids (CS, inhaled and/or oral) and the number of oral CS pulses, food intake in the last month, and frequency of physical exercises. Growth velocity, bone metabolism (total serum calcium, serum phos- phoru, serum alkaline phosphatase, and 24hs urinary calcium) and bone mineral densitometry (BMD). Results: notwithstanding more than 30% of them have be- gun with mild asthma, all of them have developed to modera- te/severe asthma. There were no differences according to sex and cumulative intake of CS, and pulses of oral CS. Only 12.4% referred an appropriate calcium intake, and more than 50% of them did not exercise at least twice a week. BMD was decreased in 32. 3% of patients and was related to growth de- lay mainly among those with severe asthma, and it was no as- sociated to duration of treatment and cumulative intake of CS. Conclusions: the decrease in bone mass observed in adults after a long-term systemic CS treatment seems to occur with IC in a dose- and time-dependent way. Several factors may difficult the interpretation of our results: lack of knowledge about basal calcium reservoir before starting treatment with IC, previous use of systemic CS treatment, no physical activity and deficient calcium intake. Nevertheless, the high prevalence of BMD abnormalities observed in our patients turns bone me- tabolism monitoring obligatory during treatment with IC in pa- tients with moderate or severe asthma.