A follow-up study with acoustic rhinometry in children using nasal insulin.

Acoustic rhinometry is a widely used method especially suitable with children, since it has no side-effects and is easy to perform. The role of normal development of height or body surface area, and their effect on acoustic rhinometric results, is still a matter of debate. The purpose of this study was to determine the presence of any differences in rhinometric findings or nasal symptoms between children receiving daily administered nasal insulin or placebo. The usefulness of acoustic rhinometry for follow-up in children was also considered. A subcohort of 77 children taking part in the Type I Diabetes Prediction and Prevention Study was invited for a follow-up study with acoustic rhinometry. Children aged 1-12 years received daily either nasal insulin or a placebo. There was no difference between the two groups in nasal symptoms, minimal cross-sectional area or nasal volume measured with acoustic rhinometry. There was likewise no significant increase in rhinometric values during the two years of the follow-up. We conclude that acoustic rhinometry is a suitable method for objective follow-up in children. In a long-term follow-up the normal growth of the child should be taken into account.