Influencia de diversas variantes genéticas y el estilo de vida sobre el riesgo de obesidad en población mayor de 55 años de la cohorte SUN

Abstract

Genetic and lifestyle factors, such as dietary patterns and physical activity (PA) levels, may interact modifying obesity risk. The aim of this work was to explore the influence of diverse gene variants (rs1801282 of PPARG2 gene, rs9939609 of FTO gene and rs1801260 SNP of CLOCK gene) on obesity risk, and to examine their potential interaction with lifestyle factors in an elderly population of the SUN Project. Subjects (n=986, aged 69±6 years old) were recruited from the SUN (¿Seguimiento Universidad de Navarra¿) Project. DNA was obtained from saliva while lifestyle and dietary data were collected by validated self-report questionnaires. Genotype was assessed by RT-PCR plus allele discrimination. For the Pro12Ala gene variant of the PPARG2 (rs1801282) the Ala12 allele was associated with an increased obesity risk A significant interaction between this SNP and carbohydrate (CHO) intake for obesity risk was observed and within subjects with a high CHO intake those carrying the 12Ala allele had higher obesity risk than Pro12Pro subjects. Moreover, a meta-analysis encompassing 49.092 subjects showed higher levels of BMI in those subjects carrying the Ala12 allele. This effect was more relevant in the Caucasian men subgroup. It also was observed that the co-presence of the Ala12 allele and the A risk allele of the rs9939609 SNP of the FTO gene increased BMI levels even if no association was observed between this FTO gene variant and obesity status. Additionally, this effect was significantly enhanced in subjects with a high CHO intake and low PA levels. Finally, interaction between the 3111T/C SNP of CLOCK gene (rs1801260) and sex for overweight/obesity risk was observed. Women carrying the C allele of CLOCK gene had a lower risk of overweight/obesity compared to non carriers. This association was enhanced in those women with a high PA level. Furthermore, a significant interaction between the 3111T/C gene variant and PA for overweight/obesity risk was observed but only in women.