INSULIN-LIKE GROWTH-FACTOR-I, ITS BINDING-PROTEIN-1 AND BINDING-PROTEIN-3, AND GROWTH-HORMONE BINDING-PROTEIN IN CHILDREN AND ADOLESCENTS WITH INSULIN-DEPENDENT DIABETES-MELLITUS - CLINICAL IMPLICATIONS

Values of IGF-I after extraction, its binding proteins, and the high a ffinity GH-binding protein (BP) are not well established in pediatric patients with insulin-dependent diabetes mellitus (IDDM). We report da ta for IGF-I, IGFBP-1 and -3, and GHBP in 92 Spanish children with IDD M, separated according to pubertal stage: prepubertal (n = 49); pubert al onset (n = 17); mid-puberty (n = 17), and complete puberty (n = 9), as well as to metabolic control (HbA(1) < 9% or greater than or equal to 9%). IGF-I levels in IDDM patients increased throughout developmen t (p < 0.001), but were diminished at even, developmental stage when c ompared with matched control subjects. IGF-I concentrations showed a n egative correlation with the degree of metabolic control, in particula r during the prepubertal stage of development. A negative correlation (r = -0.22; p < 0.005) between IGF-I concentrations and HbA(1) was fou nd. Serum IGFBP-1 levels diminish during maturation in diabetic patien ts (p < 0.001), However, IDDM patients have significantly higher level s of IGFBP-1 than control subjects at every stage of development, and IDDM patients with inadequate metabolic control exhibit even greater d ifferences when compared with matched control subjects. A positive cor relation (r = 0.22; p < 0.005) between IGFBP-1 concentrations and HbA( 1) was found. IGFBP-3 serum levels were similar to those observed in n ormal subjects, and no correlation was observed in relation to the met abolic control, In IDDM patients, GHBP levels change significantly dur ing maturation, as they do in normal control subjects; however, signif icantly lower GHBP levels were found in prepubertal and pubertal IDDM patients. GHBP levels were independent of metabolic control, although a tendency reward lower levels of GHBP was seen when HbA, levels incre ased. We suggest that a partial GH resistance syndrome exists in IDDM patients, and this may be related to the metabolic control. Hence, the biochemical markers measured here may be of value in evaluating the s maller pubertal growth spurt in diabetic patients.