First investigation of two obesity-related loci (TMEM18, FTO) concerning their association with educational level as well as income: the MONICA/KORA study

International audience; Background: Strong evidence exists for an association between socioeconomic status and body mass index (BMI) as well as between genetic variants and BMI. The association of genetic variants with socioeconomic status was not investigated so far. The aim of our study was to investigate two obesity-related loci - the transmembrane 18 (TMEM18) and the fat mass and obesity associated (FTO) gene - for their association with educational level and per capita income, and to test whether the detected genotype-BMI association is mediated by these social factors. Methods: 12,425 adults from a large population-based study were genotyped for the polymorphism rs6548238 near TMEM18 and rs9935401 within FTO gene. Data on educational level and per capita income were based on standardized questionnaires. Results: High educational level and high per capita income were significantly associated with decreased BMI (-1.503 kg/m², p=