Serum transferrin as a marker of bone growth in boys: correlation with serum alkaline phosphatase activity, plasma insulin-like growth factor 1 and rate of growth in height

Transferrin (TF) has a growth promoting activity in cell culture. The aim of this work was to study possible relationships between serum TF, alkaline phosphatase activity (ALP), plasma insulin-like growth factor 1 (IGF-1) levels and rate of height increase in boys. 149 boys aged 13-15 yrs were studied. TF levels were measured using turbidimetric method. The serum levels of ALP could be used as a biochemical marker for bone formation. Significant correlation was found between serum TF levels and ALP levels (r = 0.31, P less than 0.0005). The TF levels are higher in iron-deficiency anemia. The hemoglobin (Hb) and serum ferritin were measured in all boys. Thirty-one of 149 boys had no iron-deficiency anemia (Hb 14.0 g/dl and serum ferritin 23 ng/ml). The rate of growth in height was estimated over a 5 month period. In these boys, the rate of growth in height was significantly correlated with serum TF levels (r = 0.37; P less than 0.05). A significant correlation was found between serum TF levels and plasma IGF-1 levels (r = 0.45; P less than 0.05). These data indicate that serum TF levels may be a marker of skeletal growth in normal boys.