Physical activity attenuates the body mass index-increasing influence of genetic variation in the FTO gene
ABSTRACT Intronic variation in the FTO (fat mass and obesity-associated) gene has been unequivocally associated with increased body mass index (BMI; in kg/m(2)) and the risk of obesity in populations of different ethnicity.
We examined whether this robust genetic predisposition to obesity can be attenuated by being more physically active.
The FTO variant rs1121980 was genotyped in 20,374 participants (39-79 y of age) from the European Prospective Investigation into Cancer and Nutrition-Norfolk Study, an ethnically homogeneous population-based cohort. Physical activity (PA) was assessed with a validated self-reported questionnaire. The interaction between rs1121980 and PA on BMI and waist circumference (WC) was examined by including the interaction term in mixed-effect models.
We confirmed that the risk (T) allele of rs1121980 was significantly associated with BMI (0.31-unit increase per allele; P < 0.001) and WC (0.77-cm increase per allele; P < 0.001). The PA level attenuated the effect of rs1121980 on BMI and WC; ie, whereas in active individuals the risk allele increased BMI by 0.25 per allele, the increase in BMI was significantly (P for interaction = 0.004) more pronounced (76%) in inactive individuals (0.44 per risk allele). We observed similar effects for WC (P for interaction = 0.02): the risk allele increased WC by 1.04 cm per allele in inactive individuals but by only 0.64 cm in active individuals.
Our results showed that PA attenuates the effect of the FTO rs1121980 genotype on BMI and WC. This observation has important public health implications because we showed that a genetic susceptibility to obesity induced by FTO variation can be overcome, at least in part, by adopting a physically active lifestyle.
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ABSTRACT: Few studies have investigated the association between genetic variation and obesity traits in Indian populations or the role of environmental factors as modifiers of these relationships. In the context of rapid urbanisation, resulting in significant lifestyle changes, understanding the aetiology of obesity is important. We investigated associations of FTO and MC4R variants with obesity traits in 3390 sibling pairs from four Indian cities, most of whom were discordant for current dwelling (rural or urban). The FTO variant rs9939609 predicted increased weight (0.09 Z-scores, 95% CI: 0.03, 0.15) and BMI (0.08 Z-scores, 95% CI: 0.02, 0.14). The MC4R variant rs17782313 was weakly associated with weight and hip circumference (P < .05). There was some indication that the association between FTO and weight was stronger in urban than that in rural dwellers (P for interaction = .03), but no evidence for effect modification by diet or physical activity. Further studies are needed to investigate ways in which urban environment may modify genetic risk of obesity.Journal of obesity 05/2011; 307542(7). DOI:10.1155/2011/307542
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ABSTRACT: The purpose of this study was to determine if task, coping, and scheduling self-efficacy (SE) for exercise could be influenced using guided imagery interventions in an experimental design controlling for overt exercise experiences. Healthy women (N = 205, Mage = 31.47) who did not exercise regularly were randomly assigned to guided imagery sessions targeting a specific type of SE or to a nutrition information control group. All participants attended a 12-week cardiovascular exercise program. The influence of the various imagery interventions on the three types of self-efficacy over time were assessed with two doubly multivariate ANOVAs: one from baseline to 6 weeks and the other from 6 to 12 weeks. The analyses were conducted for 61 participants who completed the exercise intervention. The first analysis demonstrated that task, coping, and scheduling SE were differentially influenced over time in response to the different imagery interventions. The results of the second analysis were non-significant, revealing that the main changes in SE were observed within the first half of the 12-week intervention. This study demonstrates that task, coping, and scheduling SE can be seen as independent from one another and that mental imagery interventions are an effective means for influencing exercise-related cognitions.Applied Psychology Health and Well-Being 02/2011; 3(1):107 - 126. DOI:10.1111/j.1758-0854.2010.01043.x · 1.75 Impact Factor
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ABSTRACT: Obesity is a complex disease that results from the interaction between lifestyle (dietary patterns and sedentary habits) and genetic factors. The recognition of a genetic basis for human obesity has driven to identify putative causal genes to understand the pathways that control body mass and fat deposition in humans as well as to provide personalized treatments and prevention strategies to fight against obesity. More than 120 candidate genes have been associated with obesity-related traits. Genome-wide association study has so far identified over 20 novel loci convincingly associated with adiposity. This review is specifically focused on the study of the effects of melanocortin 4 receptor, Peroxisome proliferator-activated receptor γ and fat mass and obesity associated (FTO) gene variants and their interactions with dietary intake, physical activity or drug administration on body weight control. The advances in this field are expected to open new ways in genome-customized diets for obesity prevention and therapy following personalized approaches.Molecular Nutrition & Food Research 01/2011; 55(1):136-49. DOI:10.1002/mnfr.201000445 · 4.91 Impact Factor