Serum levels of leptin, insulin-like growth factor-1 and growth hormone in children with insulin dependent diabetes mellitus: the effect of metabolic control and pubertal development

ABSTRACT

The existing literature on the relation between serum leptin and growth hormone [GH] / insulin like growth factor-1 [IGF-1] axis in insulin dependent diabetes mellitus [IDDM] is conflicting. The present study included 45 children and adolescents with IDDM [22 recently diagnosed and 23 old known diabetics], aged from 6-14 years, they were 26 girls and 19 boys, together with 16 apparently healthy control children of matchable age and sex. All patients and controls were subjected to complete medical history and clinical examination including calculation of body mass index [BMI] and pubertal staging. The serum levels of leptin, C-peptide, CH and IGF-1 were determined in all patients and controls. Glycemic control was assessed by glycosylated hemoglobin [HbA1C]. Diabetic children showed significantly higher mean values of serum levels of leptin and GH than controls. This was true for the diabetic children in general, for those with poor metabolic control [HbA1C>9%], for the old diagnosed diabetics as well as the pubertal diabetic adolescents. On the other hand, the whole diabetic cases, prepubertal adolescent diabetics, the recently diagnosed ones and those with poor metabolic control showed significant lower serum levels of IGF-1 than their comparable partners. In all diabetic cases, serum levels of leptin as well as lGF-1 were positively correlated with BMI and C-peptide. However, leptin and GH showed significant positive correlation in pubertal diabetics only. IGF-1 levels were negatively correlated with HbA1C in the studied diabetic children, while no correlation could be detected between serum leptin and IGF-1 or between GH levels and either of IGF-1 or BMI in diabetic cases. Leptin and GH /IGF-1 system are altered in IDDM in relation to the degree of metabolic control and the pubertal changes. The improvement of glycemic control may help to correct such ulterations. The effect of these changes needs further studies to be settled