Sensitivity to sedentary lifestyle
Exercise and fat breakdown
It is a well-known fact that sedentary lifestyle promotes obesity and related disease. However, it is less known that some people are more sensitive then others to the risks of being inactive.
ADRB3 variant carriers have 3 times the risk for obesity. A physically active lifestyle nullifies this risk.
Get gene-informed and test your ADRB3. Learn what scientists found to be efficient for your weight lost efforts.
Gene: BETA-3-ADRENERGIC RECEPTOR (ADRB3)
Genomic coordinates (GRCh38): 8:37,962,994-37,966,665
Sedentary lifestyle is a major risk factor for heart disease, diabetes, cancer, and obesity. Sedentary lifestyle is usually defined as being active less then half the time spent by sitting.
Some individuals have an additional genetic predisposition to gain weight when not active. Carriers of a variant in the ADRB3 gene have 3 times more risk for obesity, when living sedentary lifestyle.
The ADRB3 gene is expressed in adipose tissue ('fat cells') in visceral (internal) organs. This gene plays a significant role in controlling energy expenditure through its role in the regulation of lipolysis ('fat breakdown') and thermogenesis (body heat). Variants of this gene were extensively studied in regard to obesity and energy expenditure.
As shown on the right hand side of the figure below, physically active individuals have an average weight (BMI), regardless of their genotype. On the left side of figure, it is shown that inactive individuals generally more obese, as expected. However, the surprise here is that people with a certain ADRB3 variant (black bar) show a significantly higher weight when having a sedentary lifestyle. These individuals have a genetic risk factor for obesity, but with an option to control it by changing their lifestyle habits.
In another study of 12 months of supervised exercising, high intensity resistance training and moderate impact weight bearing have erased the negative predisposition of the variant. On right side of figure, light bar (representing the risk carriers) and dark bar (controls) are equal, showing that both groups lost weight regardless of genotype. Among the controls, who did not perform physical activity during the study follow-up, carriers gained another 1.6% to their body fat (left, light bar).
The 12-month intervention program included high intensity resistance training and moderate impact weightbearing exercise for 75 min, 3 days/week. Eight weight training exercises were performed per session, where individuals completed two sets of 6–8 repetitions at 70–80% of the one-repetition maximum loads per exercise.