Physical activity and sex modulate obesity risk linked to 3111T/C gene variant of the CLOCK gene in an elderly population: the SUN Project

Abstract

Genetic factors may interact with physical activity levels to modify obesity risk. Our aim was to explore the effect of rs1801260 SNP (3111T/C) of CLOCK gene, on obesity risk and to examine their interaction with lifestyle factors in an elderly population of the SUN Project. Subjects (n=903, aged 69±6) were recruited from the SUN (“Seguimiento Universidad de Navarra”) Project. DNA was obtained from saliva and lifestyle and dietary data were collected by validated self-reported questionnaires. Genotyping was assessed by RT-PCR plus allele discrimination. A significant interaction between the 3111T/C SNP of CLOCK gene and sex for overweight/obesity risk was observed (p for interaction [Sex*CLOCK] interaction <0.001). Our results showed that women carrying the C allele of CLOCK gene had a decreased overweight/obesity risk compared to non carrier -TT- subjects (OR 0.61, 95% CI: 0.36-1.04, p=0.069). Moreover, the protective effect of the 3111T/C gene variant may be enhanced in those women with a high physical activity practice. We found that women practicing more than 16.8 METs- h/week had a significantly lower overweight/obesity risk (OR 0.36, 95%CI: 0.17-0.79, p=0.011). A significant interaction between the 3111T/C gene variant and physical activity for overweight/obesity risk was observed in women (p for [PA x CLOCK] interaction=0.015). In conclusion, it appears that physical activity levels may act as an effect modifier for overweight/obesity risk linked to the 3111T/C SNP (rs1801260) of the CLOCK gene in an elderly population of the SUN Project.