Thr-encoding allele homozygosity at codon 54 of FABP 2 gene may be associated with impaired delta 6 desatruase activity and reduced plasma arachidonic acid in obese children.
BACKGROUND
Alanine-for-threonine substitution at codon 54 (A54T polymorphism) in the fatty acid-binding protein 2 gene (FABP2) has been associated with hypertriglyceridemia and insulin resistance. Impairment in the activity of delta 6 and 5 desaturases is also supposed to be a factor predisposing the development of insulin resistance syndrome.


OBJECTIVE
We investigated the relationship between A54T polymorphism in FABP2 and the impairment of long-chain polyunsaturated fatty acid metabolism in obese children.


METHODS
Thirty-two obese children participated. During the study, the children continued their habitual diet, which was documented in a 3-day food record using household measures. Anthropometry was performed, and serum lipid and fatty acid composition in plasma were analyzed. The polymorphism of codon 54 in the FABP 2 gene was analyzed.


RESULTS
The allele frequency was 0.66 and 0.34 for Ala54 and Thr54, respectively. There were no significant differences in age, body mass index, fasting serum glucose, insulin or serum lipoproteins among the three polymorphism groups. These were also no significant differences in the intake of energy, the percentage of energy nutrients or in the dietary lipid composition. The content of arachidonic acid (AA) in plasma was lowest in Thr/Thr54 (p < 0.05). The indices of delta-6 desaturase (D6D) activity in Thr/Thr54 were significantly lower than in Thr/Ala54 or Ala/Ala54 (p < 0.05, p < 0.01, respectively).


CONCLUSIONS
In obese children, Thr/Thr54 of the FABP 2 gene is associated with impaired activation of D6D and reduced AA content. The results in the LCPUFA profile suggest that Thr/Thr54 may predispose the to development of insulin resistance.
Okada
Tomoo
T
Department of Pediatrics, Nihon University School of Medicine, Tokyo, Japan. tomokada@med.nihon-u.ac.jp
Sato
Noriko F
NF
Kuromori
Yuki
Y
Miyashita
Michio
M
Iwata
Fujihiko
F
Hara
Mitsuhiko
M
Harada
Kensuke
K
Hattori
Hiroaki
H
D000293:Adolescent; D000483:Alleles; D016718:Arachidonic Acid / Q000097:blood* / Q000378:metabolism; D002648:Child; D003062:Codon; D050556:Fatty Acid-Binding Proteins / Q000235:genetics* / Q000502:physiology*; D005260:Female; D005787:Gene Frequency; D006720:Homozygote; D006801:Humans; D007333:Insulin Resistance; D050602:Linoleoyl-CoA Desaturase / Q000378:metabolism*; D008297:Male; D009765:Obesity; D011110:Polymorphism, Genetic
D003062:Codon; C493404:FABP2 protein, human; D050556:Fatty Acid-Binding Proteins; D016718:Arachidonic Acid; D050602:Linoleoyl-CoA Desaturase