Growth hormone-binding proteins and insulin-like growth factor-binding proteins in protein-energy malnutrition, before and after nutritional rehabilitation.
To clarify the influence of nutrition on the GH-IGF axis in protein-energy malnutrition (PEM), we determined the serum levels of GH, GH-binding proteins (BP) (GHBPs), IGF-I, and IGFBPs in nine children with kwashiorkor and 13 with marasmus, before and after nutritional rehabilitation. In a basal condition, the GH level was significantly higher in the two malnourished groups than in controls (p < 0.01); in contrast, the second fraction of GHBP was lower and seemed to be related to the high GH and to a reduction in GH receptors. After refeeding, the GH level increased and the second fraction of GHBP decreased. The IGF-I basal level was higher in kwashiorkor than in marasmus subjects (p < 0.05), but in both groups it was significantly lower than in controls (p < 0.01); after refeeding it increased. IG-FBP-3, measured by RIA and Western blotting techniques, was in the control range in the kwashiorkor group but in the marasmic group it was significantly lower than in controls; after refeeding it decreased in kwashiorkor (p < 0.01 versus basal values) and increased in marasmus (p < 0.05 versus prerefeeding level). When sera of malnourished patients were mixed with adult control sera, incubated for 5 h at 37 degrees C, and assessed by ligand blotting, a low IGFBP-3 level in marasmus was found to be due to increased adaptive proteolysis of IGFBP-3; in contrast, in kwashiorkor the IGFBP-3 proteolytic activity was very low, probably because of inhibition by aflatoxins. These findings confirm that malnutrition affects the GH-IGF axis.
Zamboni
G
G
Pediatric Clinic of University, Verona, Italy.
Dufillot
D
D
Antoniazzi
F
F
Valentini
R
R
Gendrel
D
D
Tato
L
L
D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D001827:Body Height; D001835:Body Weight; D002352:Carrier Proteins / Q000097:blood*; D002675:Child, Preschool; D005260:Female; D013006:Growth Hormone / Q000097:blood; D006801:Humans; D007223:Infant; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000378:metabolism*; D018969:Insulin-Like Growth Factor Binding Proteins / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008297:Male; D011502:Protein-Energy Malnutrition / Q000378:metabolism* / Q000534:rehabilitation*
D001786:Blood Glucose; D002352:Carrier Proteins; D018972:Insulin-Like Growth Factor Binding Protein 3; D018969:Insulin-Like Growth Factor Binding Proteins; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; C051815:somatotropin-binding protein