Regular monitoring of bone age is useful in children treated with growth hormone.

Objective. This study was undertaken to determine whether serial bone age (BA) radiographs were obtained in patients with growth hormone deficiency and to assess whether there were differences in outcome between subjects with and without monitoring of BA radiographs. Research Design and Methods. Data were collected from the National Cooperative Growth Study database on growth hormone-deficient subjects who were treated for at least 3 years. Comparisons were made among three groups of subjects: 1) those with BAs at entry versus those without; 2) those with BA values in the first year of follow-up if an entry radiograph had not been done versus those with no first-year examination; and 3) those with a BA at entry and yearly for 3 years versus those with no radiographs during the same period. Differences in the change in height standard deviation score (SDS); change in height age, age, pubertal progression, number of visits, growth hormone dosage; and number of growth hormone injections per week were compared. Results. Of the 6191 subjects assessed, 93% had at least one BA radiograph obtained; there was a mean of 3.6 +/- 2.6 total number of BA radiographs per patient during the 5.2 +/- 1.9 years of follow-up. Subjects with BA values at entry were older and had slightly higher cumulative height SDS and height age change compared with those without BA values at entry. Subjects with BA assessment during the first year were older and had shorter growth hormone treatment time and slightly better cumulative change in height SDS and height age than did those without BA in the first year. Comparing those with serial BA determination for the first 3 years of treatment versus those with no BA values, those with BA were older, more pubertal, seen more often, had more growth hormone injections per week of a comparable growth hormone dosage, and had slightly larger cumulative change in height SDS and height age than those without x-rays. Conclusions. These data suggest that National Cooperative Growth Study investigators find it of benefit to obtain baseline and follow-up measurements of BA in most subjects treated with growth hormone. Subjects with BA monitoring do slightly better than do those whose skeletal maturation is not measured. BA assessment should be considered part of the follow-up of patients treated with growth hormone therapy.