TAS2R38 and Its Influence on Smoking Behavior and Glucose Homeostasis in the German Sorbs

Background: Genetic variants within the bitter taste receptor gene TAS2R38 are associated with sensitivity to bitter taste and are related to eating behavior in the Amish population. Sensitivity to bitter taste is further related to anthropometric traits in an genetically isolated Italian population. We tested whether the TAS2R38 variants (rs713598; rs1726866 and rs10246939) may be related to eating behavior, anthropometric parameters, metabolic traits and consumer goods intake in the German Sorbs. Materials and Methods: The three SNPs were genotyped in a total cohort of 1007 individuals (male/female: 405/602). The German version of the three-factor eating questionnaire was completed by 548 individuals. Genetic association analyses for smoking behavior, alcohol and coffee intake, eating behavior factors (restraint, disinhibition and hunger) and other metabolic traits were analyzed. Further, by combining the three SNPs we applied comparative haplotype analyses categorizing PAV (proline-alanine-valine) carriers (tasters) vs. homozygous AVI (alanin-valine-isoleucine) carriers (non-tasters). Results: Significant associations of genetic variants within TAS2R38 were identified with percentage of body fat, which were driven by associations in women. In men, we observed significant associations with 30 min plasma glucose, and area under the curve for plasma glucose (0-120 min) (all adjusted P <= 0.05). Further, we found that carriers of at least one PAV allele show significantly lower cigarette smoking per day (P=0.002) as well as, albeit non-significant, lower alcohol intake. We did not confirm previously reported associations between genetic variants of TAS2R38 and eating behavior. Conclusion: Our data suggest that genetic variation in TAS2R38 is related to individual body composition measures and may further influence consumer goods intake in the Sorbs possibly via individual sensitivity to bitter taste.