The role of rs2237781 withinGRM8in eating behavior

Abstract

Introduction:The glutamate receptor, metabotropic 8 gene (GRM8) encodes a G-protein-coupled glutamate receptor and has been associated with smoking behavior and liability to alcoholism implying a role in addiction vulnerability. Data from animal studies suggest that GRM8 may be involved in the regulation of the neuropeptide Y and melanocortin pathways and might influence food intake and metabolism. This study aimed to investigate the effects of the genetic variant rs2237781 within GRM8 on human eating behavior. Methods:The initial analysis included 548 Sorbs from Germany who have been extensively phenotyped for metabolic traits and who completed the German version of the three-factor eating questionnaire. In addition, we analyzed two independent sample sets comprising 293 subjects from another German cohort and 430 Old Order Amish individuals. Genetic associations with restraint, disinhibition, and hunger were assessed in an additive linear regression model. Results:Among the Sorbs the major G allele of rs2237781 was significantly associated with increased restraint scores in eating behavior (P = 1.9 × 10−4; β = +1.936). The German cohort and the Old Order Amish population revealed a trend in the same direction for restraint (P = 0.242; β = +0.874; P = 0.908; β = +0.096; respectively). A meta-analysis resulted in a combined P = 3.1 × 10−3 (Z-score 2.948). Conclusion:Our data suggest that rs2237781 within GRM8 may influence human eating behavior factors probably via pathways involved in addictive behavior.

A genetic variant in proximity to the gene LYPLAL1 is associated with lower hunger feelings and increased weight loss following Roux-en-Y gastric bypass surgery

“…reported a gene variant, located within the gene GRM8 , to be associated with BMI and Cognitive restraint in a cohort of 548 healthy subjects. [ 30 ] These findings support our concept that genetic variants may have the potential to impact weight via a change of eating behavior.…”

Role of genetic variants in ADIPOQ in human eating behavior

“…A total of 1,036 subjects with mean age of 48 ± 16 years and mean BMI 26.9 ± 4.9 kg/m 2 were included. A total of 548 Sorbs completed the FEV (Pudel and Westenhöfer 1989), the German version of the TFEQ (Stunkard and Messick 1985) as described elsewhere (Gast et al 2013). Total adiponectin serum levels were measured in the Sorbs population.…”

“…The replication cohort is an independent German population described elsewhere (Gast et al 2013). A total of 350 individuals were included in the analysis (mean age of 27 ± 5 years and mean BMI of 27.0 ± 6.2 kg/m 2 ; Table 1).…”

Genetic variants in AKR1B10 associate with human eating behavior

“…For subjects recruitment, the study was advertised by flyers, newspapers, radio and by local general practitioners. 618 Sorbs out of 1046 completed the German version of the three factor eating questionnaire (FEV) which determines the three main eating behavior factors - disinhibition, hunger and restraint as described in detail elsewhere [ 18 , 31 , 32 ]. In the here presented study type 2 diabetes (T2D) was the only exclusion criterion because diabetic individuals usually control their food intake according to specific nutrition plans.…”

“…For replication purposes we used another independent German cohort as described elsewhere [ 18 ] including 350 healthy individuals (152 women and 198 men). Briefly, phenotyping included anthropometric measurements (BMI and weight), age, sex and data for eating behavior, which were assessed using the German version of the three factor eating questionnaire (FEV) [ 31 ].…”