Alanine amino transferase concentrations are linked to folate intakes and methylenetetrahydrofolate reductase polymorphism in obese adolescent girls.
OBJECTIVE
The objective of this study was to investigate the consequences of low dietary folate intake and the impact of the 677 C-->T methylenetetrahydrofolate reductase (MTHFR) common mutation on liver function in obese adolescents.


METHODS
Fifty-seven obese girls (BMI = 36.1 +/- 6.0 kg/m) aged 14.1 +/- 1.5 years were included before starting a weight reduction program. Dietary intakes for folate were assessed by means of an adapted food frequency questionnaire (n = 50). Liver enzymes, plasma lipids, glucose metabolism parameters, ferritin, homocysteine and erythrocyte folate content were measured in plasma or blood obtained under fasting conditions. The MTHFR 677 C-->T polymorphism, which is associated with decreased enzyme activity, was determined using PCR. Body composition was assessed using dual x-ray absorptiometry.


RESULTS
Twenty-three subjects were heterozygote (CT) for the mutation and 5 were homozygote (TT). An increase in alanine amino transferase (ALT) and ALT/aspartate aminotransferase ratio was associated with the mutation (F = 4.46, P = 0.016 and F = 5.92, P = 0.0049, respectively). Alanine amino transferase was correlated negatively to folate intake (r = -0.32, P = 0.024) (n = 50) and positively to homocysteine concentrations (r = 0.30, P = 0.025). Body composition was similar among the 3 genotypic groups. Ferritin was also correlated to ALT concentrations of the entire group (P = 0.009).


CONCLUSIONS
Our data suggest that folate intake and the MTHFR polymorphism represent a part of the link between antioxidant status and liver disease in obese adolescent girls.
Frelut
Marie-Laure
ML
Pediatric Therapy Center, Margency, France.
Emery-Fillon
Nathalie
N
Guilland
Jean-Claude
JC
Dao
Hunh Han
HH
de Courcy
Geneviève Potier
GP
D000293:Adolescent; D000410:Alanine Transaminase / Q000097:blood / Q000378:metabolism*; D000975:Antioxidants / Q000378:metabolism; D001219:Aspartate Aminotransferases / Q000097:blood; D005234:Fatty Liver / Q000201:enzymology / Q000209:etiology / Q000235:genetics; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage* / Q000097:blood; D005838:Genotype; D006579:Heterozygote; D006710:Homocysteine / Q000097:blood; D006720:Homozygote; D006801:Humans; D008099:Liver / Q000201:enzymology*; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000097:blood / Q000235:genetics; D009767:Obesity, Morbid / Q000150:complications* / Q000178:diet therapy / Q000201:enzymology; D011110:Polymorphism, Genetic; D011795:Surveys and Questionnaires; D014803:Vitamin B Complex / Q000008:administration & dosage* / Q000097:blood
D000975:Antioxidants; D006710:Homocysteine; D014803:Vitamin B Complex; D005492:Folic Acid; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase