title: The G1422A variant of the cannabinoid receptor gene (CNR1) is associated with abdominal adiposity in obese men.
abstract: Since recent data suggest that the endocannabinoid system controls food intake through central, and lipogenesis via peripheral CB1 receptors, we hypothesized that genetic variation at the cannabinoid receptor-1 (CNR1) locus could have an effect on adiposity. We investigated, whether a specific CNR1 G1422A genotype is associated with anthropometric markers of obesity and fat distribution in adult obese individuals. A total of 1,064 obese subjects (BMI > or = 30 kg/m2) without diabetes, impaired glucose tolerance or other endocrine diseases and 251 healthy control persons were genotyped for the G1422A variant (rs1049353) with a TaqMan assay. Anthropometric measures as body weight, BMI, waist and waist-to-hip ratio (WHR) were assessed by classical methods. Fat mass (FM) was measured by bio-impedance. The prevalence of the G1422A variant was not significantly different between cases and controls (OR = 1.056; P = 0.626). In obese women, no meaningful associations between CNR1 genotype and anthropometric parameters were found. In obese men, CNR1 1422 A/A genotype was significantly associated with higher WHR (P = 0.009) and waist circumference (P = 0.008) after adjusting for age and BMI. Fat mass percentage showed an association (P = 0.011) which disappeared after adjusting for age and BMI. A trend for an association was seen for fat mass (unadjusted P = 0.099; adjusted P = 0.033). Our data indicate that the G1422A polymorphism in the CNR1 gene is associated with increased abdominal adiposity in obese men.
authors.affiliation: Department of Medical Genetics, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, Antwerp University, Universiteitsplein 1, Wilrijk, Antwerp, 2610, Belgium. armand.peeters@ua.ac.be
authors.forename: Armand
authors.initials: A
authors.lastname: Peeters
authors.forename: Sigri
authors.initials: S
authors.lastname: Beckers
authors.forename: Ilse
authors.initials: I
authors.lastname: Mertens
authors.forename: Wim
authors.initials: W
authors.lastname: Van Hul
authors.forename: Luc
authors.initials: L
authors.lastname: Van Gaal
mesh_terms: D050153:Abdominal Fat / Q000378:metabolism / Q000473:pathology; D050154:Adiposity / Q000235:genetics*; D000328:Adult; D000409:Alanine / Q000235:genetics; D016022:Case-Control Studies; D005260:Female; D005998:Glycine / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D043884:Receptor, Cannabinoid, CB1 / Q000235:genetics*
chemical_list: D043884:Receptor, Cannabinoid, CB1; D000409:Alanine; D005998:Glycine