High genetic risk individuals benefit less from resistance exercise intervention.
OBJECTIVE
Genetic factors have an important role in body mass index (BMI) variation, and also likely have a role in the weight loss and body composition response to physical activity/exercise. With the recent identification of BMI-associated genetic variants, it is possible to investigate the interaction of these genetic factors with exercise on body composition outcomes.


METHODS
In a block-randomized clinical trial of resistance exercise among women (n=148), we examined whether the putative effect of exercise on weight and dual-energy x-ray absorptiometry-derived body composition measurements differs according to genetic risk for obesity. Approximately one-half of the sample was randomized to an intervention consisting of a supervised, intensive, resistance exercise program, lasting 1 year. Genetic risk for obesity was defined as a genetic risk score (GRS) comprised of 21 single-nucleotide polymorphisms (SNPs) known to be associated with BMI variation. We examined the interaction of exercise intervention and the GRS on anthropometric and body composition measurements after 1 year of the exercise intervention.


RESULTS
We found statistically significant interactions for body weight (P=0.01), body fat (P=0.01), body fat % (P=0.02) and abdominal fat (P=0.02), whereby the putative effect of exercise is greater among those with a lower level of genetic risk for obesity. No single SNP appears to be a major driver of these interactions.


CONCLUSIONS
The weight-loss response to resistance exercise, including changes in body composition, differs according to an individual's genetic risk for obesity.
Mel and Enid Zuckerman College of Public Health, Department of Epidemiology and Biostatistics, University of Arizona, Tucson, AZ, USA.
Y C
YC
Klimentidis
University of Arizona Cancer Center, University of Arizona, Tucson, AZ, USA.|Department of Nutritional Sciences, University of Arizona, Tucson, AZ, USA.
J W
JW
Bea
Department of Physiology, University of Arizona, Tucson, AZ, USA.
T
T
Lohman
Mel and Enid Zuckerman College of Public Health, Department of Epidemiology and Biostatistics, University of Arizona, Tucson, AZ, USA.
P-S
PS
Hsieh
Department of Nutritional Sciences, University of Arizona, Tucson, AZ, USA.
S
S
Going
Mel and Enid Zuckerman College of Public Health, Department of Epidemiology and Biostatistics, University of Arizona, Tucson, AZ, USA.
Z
Z
Chen
D050153:Abdominal Fat; D015502:Absorptiometry, Photon; D000222:Adaptation, Physiological / Q000235:genetics*; D000328:Adult; D001823:Body Composition; D015992:Body Mass Index; D002149:Energy Intake; D004734:Energy Metabolism; D015444:Exercise; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008875:Middle Aged; D009765:Obesity / Q000235:genetics* / Q000378:metabolism / Q000503:physiopathology / Q000628:therapy*; D055070:Resistance Training; D012307:Risk Factors; D015431:Weight Loss