Prepubertal IGF-1 and Possible Relation with Physical Features of Growth and Type 1 Diabetes Mellitus

T1DM is considered as the most common chronic metabolic autoimmune disorder in childhood and adolescence as well as in the early adulthood. It appears frequently during 12- 13 years of age with distinctive features like immune-mediated chronic damage of pancreatic β-cells, leading eventually to partial, or mostly, absolute insulin deficiency. Insulin-like growth factor 1 (IGF-1) is a polypeptide consisting of 70 amino acids with insulin-like chemical structure. In most cases, IGF-1 is a reliable growth marker and an anabolic one in adults. It plays an important role in the regulation of various physiological functions, e.g., glucose metabolism, cell survival and proliferation.

To compare the levels of IGF-1 in children having type-1 diabetes with that of healthy controls and also to determine whether there is a relationship between IGF-1 and physical features in T1DM.

The current study was conducted on 85 children of both sexes. Seventy patients were less than 12 years old with T1DMselected according to ADA 2014 criteria for diagnosis of diabetes from pediatric diabetes clinic at Ain Shams University hospital. All patients were divided into 2 groups based on the duration of diabetes to T1DM>1year duration and T1DM<1year duration and they were compared with fifteen normal children, attending the pediatric general clinics as a control group. Measurements of height, weight, and arm span, upper body segment, lower body segment, and body mass index, parents' height beside Fasting blood glucose, HbA1C, IGF-1, FSH, and LH were noted.

Height percentile significantly higher inT1DM less than 1 year median 50 (10 to 75) than T1DM more than one year (median10 (3 to 44) p-value 0.007). IGF-1 level in the group of T1DM less than 1year median 90 (70 to 110) (ng/ml) was significantly lower than other groups (p-value 0.0008). IGF1 has a significant positive relation with Aram span in group T1DM more than 1year (p-value 0.024), positive significant relationship between mother height and IGF-1 level in group T1DM less than 1 year (p-value 0.013).

IGF-1 level is reduced by the recent onset of T1DM but still it has some effect on the somatic features even in the presence of longstanding diabetes.