Title: Attenuation of the Effect of the FTO rs9939609 Polymorphism on Total and Central Body Fat by Physical Activity in Adolescents: The HELENA Study
Topic: Prevention/Vascular
Date Posted: 4/16/2010
Author(s): Ruiz JR, Labayen I, Ortega FB, et al., on behalf of the HELENA Study Group.
Citation: Arch Pediatr Adolesc Med 2010;164:328-333.
Clinical Trial: No
Study Question: Does physical activity attenuate the effect of the FTO rs9939609 polymorphism on body fat in adolescents?
Methods: Data from the subjects enrolled in the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study were used for the present analysis. A total of 3,865 adolescents were recruited into the study, of which 1,155 provided blood samples; 752 of these were tested for the FTO rs9939609 polymorphism and had data on physical activity. Physical activity was assessed through accelerometry worn for between 3 and 7 days for at least 8 hours. Weight, height, waist circumference, and triceps and subscapular skinfold thickness were measured.
Results: A total of 752 (413 girls) were included in the study. The A allele of the FTO rs9939609 polymorphism was significantly associated with high body mass index (BMI) (+0.42 per risk allele), higher body fat percentage (+1.03% per risk allele), and higher waist circumference (+0.85 cm per risk allele). Significant or borderline gene-physical activity interactions were observed for BMI (p = 0.02), body fat percentage (p = 0.06), and waist circumference (p = 0.10). The effect of the FTO rs9939609 polymorphism on body fat was lower among adolescents who met daily physical activity recommendations (defined as 60 minutes per day or more of moderate to vigorous physical activity) compared with those who did not meet these activity guidelines. Results were similar for boys and girls.
Conclusions: The investigators concluded that adolescents who met daily physical activity recommendations may significantly reduce the effect of the FTO rs9939609 polymorphism on obesity.
Perspective: These data support recommendations for daily physical activity among children and adolescents. Further research such as randomized controlled trials to study the association of physical activity and body fat in relation to the FTO rs9939609 polymorphism would add to these current findings. Elizabeth A. Jackson, M.D., F.A.C.C.
Title: Prospective Randomized Comparison Between the Conventional Electroanatomical System and Three-Dimensional Rotational Angiography During Catheter Ablation for Atrial Fibrillation
Topic: Arrhythmias
Date Posted: 4/16/2010
Author(s): Knecht S, Wright M, Akrivakis S, et al.
Citation: Heart Rhythm 2010;7:459-465.
Clinical Trial: No
Study Question: Does three-dimensional rotational atriography (3DRA) affect the outcome of radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) compared to electroanatomical mapping (EAM) systems?
Methods: Ninety-one patients (mean age 58 years) undergoing RFCA of AF (persistent in 63%) were randomly assigned to 3DRA (n = 47) or imaging with a Carto EAM system (n = 44). The RFCA strategy consisted of pulmonary vein isolation plus substrate modification as clinically indicated.
Results: There was no significant difference in the mean time required for 3DRA (14 minutes) versus creation of the Carto map (17 minutes). The mean procedure time was 224 minutes and did not differ significantly between the 3DRA and Carto groups. There was no significant difference in radiation exposure between the two groups. At a mean of 10 months of follow-up, 52% of patients were free of AF/flutter, with no significant difference between the two study groups.
Conclusions: 3DRA does not increase the amount of radiation exposure compared to an EAM system and does not affect the efficacy of RFCA of AF.
Perspective: In theory, a major advantage of 3DRA over EAM is that it provides an accurate, real-time reconstruction of the left atrium (LA) and pulmonary veins that is not operator dependent. Although EAM can be integrated with anatomically accurate computed tomography (CT) images of the LA, LA volume may have been different at the time of CT and CT exposes patients to more radiation than 3DRA. Disadvantages of 3DRA include its lack of advanced mapping functions and the need for a contrast agent. This study shows that either imaging modality can be used, depending on operator preference, without compromising clinical outcomes. Fred Morady, M.D., F.A.C.C.
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