Study of serum levels of insulin-like growth factor -1, insulin - like growth factor bunding protein -1 and -3, prealbumin and aminoterminal propetide of type -1 procollagen in infants and children with protein energy malnutrition

Abstract

Protein energy malnutrition (PEM) is a range of pathological conditions arising from coincident deficiency of proteins and calories in varying proportions occurring mostly in infants and young children. According to Welcome classification, PEM is classified into mild form (underweight) and severe form (marasmus, kwashiorkor or marasmic kwashiorkor) (Wellcome, 1970). The assessment of nutritional condition may be done through clinical examination, anthropometric measures or biochemical tests. The insulin-like growth factors (IGFS), are defined as polypeptide growth factors secreted by the liver and other tissues in response to stimulation by growth hormone (GH) (Guyton, 1996). In humans, there are two main forms of IGFS: Irsulin-like growth foctor-1 (IGF-1) and insulin-like growth foctor-11 (IGF-11). The most important of these is IGF-1, its synthesis is GH dependent, and its plasma levels are very sensitive to changes in GH availability (Berne et al, 1998). The IGFS circulate in plasma in complex with a family of binding proteins that extend the serum half-life of the IGF peptides, transport the IGFS to target cells and modulate the interaction of the IGFS with surface membrane receptors (Reiter and Rosenfeld, 1998). There are six IGF - binding proteins (IGFBPS) designated IGFBP-1 to IGFBP-6. They are designated on the basis of their amino acid sequence (Berne et al, 1998). IGFBP-1 is generating much interest, because it possesses properties that are a typical for a classical binding protein. It is an important modulator of IGF activities (Martina et al, 1997). IGFBP-3 is the major IGFBP in the circulation (Boisclair et al, 2001). The prealbumin is a protein synthesized by the liver. It plays an important role in the plasma transport of vitamin A, and also involved in the transport of thyroid hormones (Silverman and Christenson, 1994) The aminoterminal peptide of procollagen, are removed during processing of collagen and released into the circulation. The level of procollagen peptides may provide a clinically useful index of growth (Raisz et al., 1998). -Aim of work : The aim of work is to evaluate serum levels of IGF-1 , IGFBP-1 , IGFBP-3 , prealbumin and aminoterminal propeptide of type 1 procollagen in malnourished children and demonstrate the effect of malnutrition on these parameters