The alpha 2-adrenergic receptor gene and body fat content and distribution: the HERITAGE Family Study.
BACKGROUND
Among adrenergic receptor subtypes that regulate lipid mobilization, the alpha2-adrenergic receptor is involved in the inhibition of fatty acid mobilization from adipose tissue. A C-1291G polymorphism is located in the alpha2-adrenergic receptor gene (ADRA2A) but no association with body fat accumulation has been reported yet.


METHODS
Body mass index (BMI), fat mass (FAT), percentage body fat (%FAT), trunk-to-extremity skinfold ratio (TER), sum of eight skinfolds (SF8), and abdominal subcutaneous (ASF), visceral (AVF), and total (ATF) fat areas assessed by CT scan have been measured in adult sedentary white (n = 503) and black (n = 276) subjects participating in the HERITAGE Family Study. Association between the C-1291G polymorphism and each phenotype was tested separately in men and women of each race using ANCOVA with the effects of age as covariate in addition to the effects of BMI for TER and of FAT for AVF, ASF, and ATF.


RESULTS
The allele frequencies of the ADRA2A C-1291G polymorphism differed between races. No association was observed in white subjects, except for a moderate effect of the polymorphism accounting for less than 1% of the variance in AVF and ATF in women. In black subjects, however, the G-1291 allele was found to be associated with an increase of TER in men (3.8% of variance accounted for by the polymorphism), while in black women it was associated with a decrease in TER (2.9%) and in AVF (2.5%).


CONCLUSIONS
These results suggest a role for the ADRA2A gene in determining the propensity to store fat in the abdominal area, independently of total body fatness.
Garenc
Christophe
C
Division of Kinesiology, Department of Preventive Medicine, Laval University, Ste-Foy, Québec, Canada.
Pérusse
Louis
L
Chagnon
Yvon C
YC
Rankinen
Tuomo
T
Gagnon
Jacques
J
Borecki
Ingrid B
IB
Leon
Arthur S
AS
Skinner
James S
JS
Wilmore
Jack H
JH
Rao
D C
DC
Bouchard
Claude
C
D000328:Adult; D044383:Black People / Q000235:genetics; D001823:Body Composition / Q000235:genetics*; D015992:Body Mass Index; D002170:Canada; D005223:Fats / Q000032:analysis*; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D010641:Phenotype; D011110:Polymorphism, Genetic / Q000235:genetics; D018341:Receptors, Adrenergic, alpha-2 / Q000235:genetics*; D014481:United States; D044465:White People / Q000235:genetics; D001741:Black or African American
D005223:Fats; D018341:Receptors, Adrenergic, alpha-2