Intestinal FABP2 A54T polymorphism: association with insulin resistance and obesity in women.
OBJECTIVE
To assess the association between the Ala54Thr genetic polymorphism of the fatty acid-binding protein 2 (FABP2) gene with insulin resistance and obesity.


METHODS
According to a sampling scheme based on BMI, 33 adult obese women (BMI > or = 30) and 30 adult normal-weight women (BMI > 18.5 and < 25 kg/m(2)) were recruited for this study. Women with chronic inflammatory diseases or acute pathology were excluded. Glucose, insulin, leptin, lipids, and tumor necrosis factor alpha (TNF alpha) were measured in fasting plasma samples. Insulin resistance was estimated through the homeostasis model assessment for insulin resistance method. The Ala54Thr allelic variant was determined by polymerase chain reaction, followed by restriction fragment-length polymorphism analysis.


RESULTS
The Thr54 allele was more frequent in obese than in nonobese women (47.0% vs. 31.7; p = 0.08). Among obese women, higher TNF alpha concentrations were found when comparing the Thr54/Thr54 genotype (30.0 +/- 7.1 pg/mL) with either the Ala54/Thr54 genotype (21.2 +/- 8.4 pg/mL) or the Ala54/Ala44 genotype (20.1 +/- 7.0 pg/mL) (p < 0.05). In addition, higher fasting plasma insulin and leptin levels were found among Thr54/Thr54 homozygotes compared with the other genotypes (p < 0.05).


CONCLUSIONS
Our results suggest that the Ala54Thr polymorphism of the FABP2 gene is associated with obesity and insulin resistance. The effect of this polymorphism might be mediated by elevated production of TNF alpha.
Department of Public Nutrition, Genetic Epidemiology Unit, Institute of Nutrition and Food Technology, University of Chile, Santiago, Chile. calbala@uchile.cl
Cecilia
C
Albala
José L
JL
Santos
Mariana
M
Cifuentes
Ana C
AC
Villarroel
Lydia
L
Lera
Claudio
C
Liberman
Bárbara
B
Angel
Francisco
F
Pérez-Bravo
D000328:Adult; D000409:Alanine / Q000235:genetics; D000483:Alleles; D015992:Body Mass Index; D002352:Carrier Proteins / Q000235:genetics*; D050556:Fatty Acid-Binding Proteins; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D007333:Insulin Resistance / Q000235:genetics*; D008875:Middle Aged; D009765:Obesity / Q000150:complications / Q000235:genetics*; D011110:Polymorphism, Genetic; D012150:Polymorphism, Restriction Fragment Length; D013912:Threonine / Q000235:genetics; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D002352:Carrier Proteins; C493404:FABP2 protein, human; D050556:Fatty Acid-Binding Proteins; D014409:Tumor Necrosis Factor-alpha; D013912:Threonine; D000409:Alanine