Effects of nutrient intake on growth, insulin-like growth factors, and their binding proteins in a Laron-type dwarf.
In Laron-type dwarfism, a basal growth rate independent of GH and insulin-like growth factor-I (IGF-I) is maintained. This represents a unique model to further assess the relationship between growth and nutritional status. In a child aged 3 yr, 7 months with severe anorexia, growth was followed in relation to his caloric intake. While receiving 496 Cal/day with 11.6 g/day protein, he grew at a rate of 2 cm/yr (period I). The mean plasma IGF-I level was below 0.07 U/mL, insulin was 3.8 +/- 0.2 microU/mL, and blood glucose was 2.9 +/- 0.3 mM/L. During moderate hyperalimentation with 1280 Cal/day and 38.3 g/day protein (period II) for 7 months, growth rate increased to 9 cm/yr with no significant change in plasma IGF-I and persistence of relative hypoinsulinemia (low response to oral glucose tolerance test). IGF-binding proteins, analyzed by Western ligand blotting, showed that 41.5- and 38.5-kilodalton forms, which were initially low, increased to form a pattern similar to that observed in hypopituitarism. These results suggest that catch-up growth did not require normal circulating GH and/or IGF-I activity. Therefore, nutrition contributes to catch-up growth and achievement of potential statural growth by a distinct cellular effect.
Crosnier
H
H
Unité de Recherche INSERM U.30, Hôpital des Enfants Malades, Paris, France.
Gourmelen
M
M
Prévot
C
C
Rappaport
R
R
D001786:Blood Glucose / Q000378:metabolism; D002352:Carrier Proteins / Q000097:blood* / Q000302:isolation & purification; D002675:Child, Preschool; D004044:Dietary Proteins; D004392:Dwarfism / Q000097:blood / Q000178:diet therapy / Q000503:physiopathology*; D002149:Energy Intake; D006128:Growth; D013006:Growth Hormone / Q000097:blood; D006801:Humans; D007328:Insulin / Q000097:blood; D018969:Insulin-Like Growth Factor Binding Proteins; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male
D001786:Blood Glucose; D002352:Carrier Proteins; D004044:Dietary Proteins; D007328:Insulin; D018969:Insulin-Like Growth Factor Binding Proteins; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone