INSULIN-LIKE GROWTH-FACTOR AND GROWTH-HORMONE SECRETION IN JUVENILE CHRONIC ARTHRITIS

Insulin-like growth factor (IGF-1) concentrations were determined in a series of 23 children with juvenile chronic arthritis in conjunction with anthropometric assessment. When standardised z scores were used significant decreases in height and weight were shown in comparison with the normal age/sex matched means. Severe growth disturbance was seen, particularly in those with prolonged disease duration, which was independent of corticosteroid treatment, indicating disease activity itself is a major factor in the growth retardation. Eight children had low IGF-1 z scores-that is, less than -2.00 from age/sex matched mean. Low IGF-1 z scores were associated with low weight z scores but not with low height z scores. Overnight growth hormone secretory profiles were determined in 10 patients, including seven with low IGF-1, and showed generally normal secretion in all but one patient, who subsequently attained normal concentrations coincident with catch up growth. Increased pulse frequency of overnight secretion was commonly seen. Low IGF-1 concentrations probably result from varying factors, particularly nutritional, but do not reflect marked endocrinological abnormalities in most patients.