Short stature in children with sickle cell anemia correlates with alterations in the IGF-I axis.
Children with sickle cell anemia (SCA) frequently have short stature. We propose that alterations in the IGF-I axis are involved in their growth failure. We investigated the IGF-I axis in children with SCA and height below the 25th percentile (n = 15) and compared it with that of children with SCA and height above the 50th percentile (n = 7). IGF-I and IGFBP-3 levels were assessed by RIA. IGFBP-3 proteolysis was assessed by a protease activity assay and by Western immunoblots. IGF-I and IGFBP-3 SDS were low for both groups. In the short statured patients, IGF-I SDS correlated with height velocity SDS (p = 0.018). IGFBP-3 SDS, when corrected for bone age, decreased with age (p = 0.0054). IGFBP-3 was proteolyzed in both groups although the short statured patients had lower levels of absolute intact IGFBP-3 when compared with the normally growing group (p = 0.028). We demonstrated that children with SCA have abnormalities in the IGF-I axis, which worsen with age.
Collett-Solberg
Paulo F
PF
Rio de Janeiro, Brazil, Department ofPediatrics, Duke University Medical Center, Durham, NC, USA. paulosolberg@netscape.net
Fleenor
Don
D
Schultz
William H
WH
Ware
Russell E
RE
D000293:Adolescent; D000375:Aging / Q000502:physiology; D000755:Anemia, Sickle Cell / Q000097:blood* / Q000503:physiopathology*; D001827:Body Height / Q000502:physiology*; D002648:Child; D010450:Endopeptidases / Q000097:blood; D005260:Female; D006128:Growth / Q000502:physiology; D013006:Growth Hormone / Q000502:physiology; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male
D018972:Insulin-Like Growth Factor Binding Protein 3; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; D010450:Endopeptidases; C080473:insulin-like growth factor binding protein-3 protease