Growth Status and Levels of Growth Factors in Children with Insulin-dependent Diabetes Mellitus

ABSTRACT

PURPOSE: It is well known that the linear growth velocity in children with insulin-dependent diabetes mellitus (type 1 DM) is closely related to metabolic control and onset age of the disease. Many studies have demonstrated growth impairment in children with type 1 DM, regardless of the degree of metabolic control, whereas other studies have found no growth retardation. Therefore, we examined the growth status and the level of growth factors in children with type 1 DM, and compared them with healthy children. METHODS: Thirty-six patients with type 1 DM (21 female, 15 male; mean age, 10.8 years range, 5-15 years)were studied. The mean duration of type 1 DM in these patients was 2.7 years (range, 0.1-7.0 years). Their growth status in height standard deviation score (HTSDS) and levels of insulin-like growth factor (IGF)-I, free IGF-I, IGF-II and IGF-binding protein (IGFBP)-3 were compared with age and sex matched normal children (21 female, 15 male; mean age, 10.3 years; range, 5-15 years). RESULTS: As HTSDS in type 1 DM, children were 0.4 +/- 1.1, no prominent growth impairment was observed in type 1 DM children. IGF-I and IGF-II levels decreased significantly in type 1 DM, but no significant differences in free IGF-I and IGFBP-3 levels compared to normal. Height in type 1 DM children was in direct correlation with free IGF-I (r=0.35, P<0.05) and IGFBP-3 (r= 0.45, P<0.01), respectively. CONCLUSION: This study reveals that the levels of IGF-I and -II are decreased in children with type 1 DM, whereas free IGF-I levels are not. These findings may be related to the decreased IGFBP-3 levels in diabetic children, and may explain no growth impairment, except in cases of extremely poor metabolic control.