Insulin-like growth factor-1 in correlation with bone mineral density among Egyptian adolescents with type 1 diabetes mellitus

Diabetes is associated with alterations in bone health in children and adolescents. The natural history and etiopathogenesis of osteoporosis in type 1 diabetes is not clear. This study was designed primarily to estimate the prevalence of osteoporosis in a sample of type 1 diabetic adolescents and to asses the level of IGF-I and its association with bone mineral density. A total of 60 type 1 diabetic patients and 40 healthy controls aged 13 to 18 years participated in the study. DEXA scan was performed in patients, serum IGF-I, urinary albumin excretion, serum calcium, phosphorus and serum alkaline phosphatase were assessed in both patients and controls. Our results revealed that 50% of our patients have impaired BMD Z score (-2.10 to -1.20), diabetic cases showed significantly lower mean IGF-I when compared to control group (P < 0.0001) and there was positive correlation between BMD and serum level of IGF-I (r = 0.66, P < 0.0001) and not with disease duration, insulin dose, HbA1c and serum metabolic bone markers. Diabetic osteopenic patients had significantly lower mean weight, height and BMI than diabetic non-osteopenic patients (P < 0.0001, P < 0.0001, P < 0.001 respectively). Moreover, age at menarche in diabetic osteopenic females is significantly delayed than non-osteopenic (P = 0.02), a higher frequency of smoking in diabetic osteopenic was observed (p < 0.0001). Impairment of bone mineral density was identified in Egyptian adolescences with T1DM. Lower serum IGF-I levels correlates with decreased mineralization, which suggests its prominent role in the pathophysiology of osteoporosis.