[Early results of ultrasound based calculation of broadband ultrasound attenuation and speed of sound in children and adolescents suffering from asthma].

PURPOSE

To determine broadband ultrasound attenuation (BUA) and speed of sound (SOS) on the os caicis in asthmatic children. To correlate these findings with sex, age, weight and height, topical steroid intake, and asthma severity grade (ASG).

PATIENTS AND METHODS

178 children (ASG 1 - 3)/(98 m, 80 f; mean age 11.9 +/- 3.1 y) were consecutively chosen from 4/00 to 9/01. Children with any other chronic disease were excluded. BUA and SOS were measured using SAHARA (Hologic lnc. Waltham, USA). Regional normative BUA and SOS data of 3 299 children (obtained with the same system), were used to calculate age-, weight- and height-matched standard-deviation-scores (SDS) for both sexes. Asthma severity grade and steroidal intake were determined. The highest topical steroid dosage was 500 micro g Fluticasone or 800 micro g Budesonide per day.

RESULTS

10/178 children were small and 7/178 tall per age (5.6 %/3.9 %), 11/178 children were light (6.2 %) and 9 heavy per age (5.0 %). 19 and 45 children had reduced BUA and SOS values, respectively. The following rates of reduced values were observed: girls: BUA 15.0 % (12/80), SOS 25.0 % (20/80); boys: BUA 7.1 %, SOS 25.5 % (7/98 and 25/98). Sexual differences were not significant. Reduced SOS-values were associated with higher severity and occurred significantly more frequent at children under steroidal intake (0.09 vs. 0.25 [BUA] and - 0.37 vs. - 0.07 [SOS]).

CONCLUSION

Following our results an increase incidence of reduced speed of sound occurs in asthmatic children which is attributed to asthma severity and seems to be negatively influenced even by topically applied low dose steroids. This could be attributed to a steroid induced collagen synthesis deficiency followed by a reduced bone elasticity. Further studies, especially using a longitudinal study design are required to verify these findings.