High genetic risk individuals benefit less from resistance exercise intervention

Abstract

Background/ObjectivesGenetic factors play an important role in body mass index (BMI) variation, and also likely play 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.Subjects/MethodsIn a block-randomized clinical trial of resistance exercise among women (n=148), we examined whether the putative effect of exercise on weight and DXA-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 one year. Genetic risk for obesity was defined as a genetic risk score (GRS) comprised of 21 SNPs known to be associated with normal BMI variation. We examined the interaction of exercise intervention and the GRS on anthropometric and body composition measurements after one year of the exercise intervention.ResultsWe 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.ConclusionsThe weight-loss response to resistance exercise, including changes in body composition, differs according to an individual’s genetic risk for obesity.

Physical activity offsets genetic risk for incident depression assessed via electronic health records in a biobank cohort study

“…Understanding how physical activity influences depression in the context of polygenic risk for depression could allow us to better classify physical activity as a protective factor with global benefits versus one that may require consideration of individual risks, consistent with a precision psychiatry approach (Fernandes et al, 2017;Stein & Smoller, 2018). Studies suggest that people could benefit to varying degrees from preventive health measures depending on their genetic risk profiles (Klimentidis et al, 2015;Natarajan et al, 2017), but little is known regarding how physical activity could influence the risk of depression in the context of genetic factors. Studies suggest that people could benefit to varying degrees from preventive health measures depending on their genetic risk profiles (Klimentidis et al, 2015;Natarajan et al, 2017), but little is known regarding how physical activity could influence the risk of depression in the context of genetic factors.…”

“…Not all interventions may be effective for all individuals, but it remains difficult to know for whom a given strategy will be efficacious. Studies suggest that people could benefit to varying degrees from preventive health measures depending on their genetic risk profiles (Klimentidis et al, 2015;Natarajan et al, 2017), but little is known regarding how physical activity could influence the risk of depression in the context of genetic factors.…”

Using misleading online media articles to teach critical assessment of scientific findings about weight loss

“…• "Women with high levels of the genes gained weight despite working out at the gym three times a week for a year" • "Those with low levels of the same genes lost weight over the year" • "Muscle-gain didn't play a part and experts say results could be because the 'obesity' gene make people feel hungrier in the wake of a workout" (20) This newspaper article is based on a study published in a respectable peer-reviewed journal (15). Students are provided with some of the key details of the study, which were that this was a block randomized trial examining the effect of resistance training on bone and body composition in early postmenopausal women.…”

“…Those randomized to the exercise group performed supervised 75-min sessions of resistance training, 3 days/wk, for 12 mo. Before and after the intervention, body mass and composition were determined by dual-energy X-ray absorptiometry (15). Participants were subsequently grouped according to "low," "moderate," or "high" genetic risk of obesity based on 21 single nucleotide polymorphisms that have previously been associated with body mass index.…”

“…Phase three: Revelation and discussion of true data. The final phase of the teaching exercise is to reveal the data presented in the published paper (15). The figures were redrawn from the original paper, and the 95% CI were calculated from the standard error, as previously described (1).…”