Department of Social and Preventive Medicine, Laval University, Quebec, Canada.
Physiol Behav. 2012 Feb 1;105(3):772-6. doi: 10.1016/j.physbeh.2011.10.015. Epub 2011 Oct 25.
Obesity is a major health problem that can be influenced by eating behaviors. Evidence suggests that the sensory properties of food influence eating behaviors and lead to overeating and overweight. A previous genome-wide linkage scan for eating behavior traits assessed with the Three-Factor Eating Questionnaire (cognitive dietary restraint, disinhibition and hunger) performed in the Quebec Family Study (QFS) revealed a quantitative trait locus for disinhibition on chromosome 19p13. This region encodes a cluster of seven olfactory receptor (OR) genes, including OR7D4, previously associated with odor perceptions. Direct sequencing of the OR7D4 gene revealed 16 sequence variants. Nine OR7D4 sequence variants with minor allele frequency (MAF)>1% as well as 100 SNPs spanning the cluster of OR genes on 19p13 were tested for association with age- and sex-adjusted eating behaviors as well as adiposity traits in 890 subjects. One OR7D4 sequence variant (rs2878329 G>A) showed evidence of association with reduced levels of adiposity (p=0.03), cognitive dietary restraint (p=0.05) and susceptibility to hunger (p=0.008). None of the OR7D4 SNPs was associated with disinhibition, but a SNP (rs2240927) in another OR gene (OR7E24) showed evidence of association (p=0.03). Another SNP in the OR7G3 gene (rs10414255) was also found to be associated with adiposity and eating behaviors. These results are the first to suggest that variations in human olfactory receptor genes can influence eating behaviors and adiposity. The associations reported in the present study should be interpreted with caution considering the number of tests performed and considered as potential new hypotheses about the effects OR polymorphisms on eating behaviors and obesity that need to be further explored in other populations.
肥胖是一个主要的健康问题，可以通过饮食习惯来影响。有证据表明，食物的感官特性会影响饮食行为，导致暴饮暴食和超重。之前对与三因素饮食问卷（认知性节食、抑制失控和饥饿）评估的饮食行为特征进行的全基因组连锁扫描，在魁北克家庭研究（QFS）中发现 19 号染色体 19p13 上存在一个与抑制失控相关的数量性状基因座。该区域编码一个包含七个嗅觉受体（OR）基因的簇，包括之前与气味感知相关的 OR7D4 基因。对 OR7D4 基因进行直接测序发现了 16 个序列变异。在 890 名受试者中，测试了 19p13 上 OR 基因簇上的 100 个 SNP 以及频率（MAF）>1%的 9 个 OR7D4 序列变异与年龄和性别调整后的饮食行为以及肥胖特征之间的关联。一个 OR7D4 序列变异（rs2878329 G>A）显示出与降低肥胖水平（p=0.03）、认知性节食（p=0.05）和饥饿易感性（p=0.008）有关的证据。没有一个 OR7D4 SNP 与抑制失控有关，但另一个 OR 基因（OR7E24）中的 SNP（rs2240927）显示出有相关的迹象（p=0.03）。在 OR7G3 基因中的另一个 SNP（rs10414255）也被发现与肥胖和饮食行为有关。这些结果首次表明，人类嗅觉受体基因的变异可以影响饮食行为和肥胖。考虑到进行的测试数量，本研究报告的相关性应谨慎解释，并将其视为关于 OR 多态性对饮食行为和肥胖影响的潜在新假设，需要在其他人群中进一步探索。
