Know Your Genes: ADRB2 - “The Adrenaline Gene”

The β2 adrenergic receptor 2 (ADRB2) gene is associated with the synthesis of β2 adrenergic receptor 2, a cell membrane spanning receptor that binds to adrenaline. Specific alleles of this gene are known to either increase or decrease the sensitivity of the body to the effects of adrenaline. Variants of the gene are shown to be associated with changes in the heart rate, size of the bronchioles, transport of oxygen and utilization of fat during exercise. There are two single nucleotide polymorphisms associated with this gene, Arg16Gly and Gln27Glu.

Association with Running:[hr height=”30″ style=”default” line=”default” themecolor=”1″]

A study conducted on elite endurance athletes showed that people with the A variant (Arg16) of the gene were more common among elite endurance athletes than among sedentary individuals. In a study conducted on Olympus marathon runners, among people who stated that they preferred running as a sport, those with the A (Arg16) variant of the gene had faster timing.

Association with Aerobic Capacity:[hr height=”30″ style=”default” line=”default” themecolor=”1″]

People with the C variant (Gln27) of the gene were associated with better aerobic capacity and increase in VO2max after aerobic training when compared with people with the G variant of the gene.

Association with carbohydrate sensitivity induced obesity:[hr height=”30″ style=”default” line=”default” themecolor=”1″]

People with the G (Gln27Glu) variant of the gene are shown to be associated with increased sensitivity to carbohydrates in the diet, wherein a high intake of carbohydrate increases the risk for obesity. In another study that was conducted on women undergoing a 12 week energy restricted diet, it was found that people with the G (Gln27Glu) variant showed a greater reduction in body weight in response to the diet intervention.

Genotype (Arg16Gly)	Phenotype
AA	[Advantage] More likely to significantly improve VO2 max with training [Advantage] More likely to have better aerobic capacity [Advantage] Better endurance running ability
AG	Moderate endurance ability and moderate aerobic capacity
GG	[Limitation] Less likely to significantly improve VO2 max with training [Limitation] More likely to have lower aerobic capacity [Limitation] Poor endurance running ability

Genotype

(Arg16Gly)

Phenotype

[Advantage] More likely to significantly improve VO2 max with training
[Advantage] More likely to have better aerobic capacity
[Advantage] Better endurance running ability

Moderate endurance ability and moderate aerobic capacity

[Limitation] Less likely to significantly improve VO2 max with training
[Limitation] More likely to have lower aerobic capacity
[Limitation] Poor endurance running ability

Genotype (Gln27Glu)	Phenotype
CC	[Advantage] More likely to significantly improve VO2 max with training [Advantage] More likely to have better aerobic capacity [Advantage] Better endurance running performance [Limitation] Higher likelihood of weight gain with higher carbohydrate intake [Advantage] More likely to utilize stored body fat for energy during exercise
CG	Moderate endurance ability and moderate aerobic capacity
GG	[Limitation] Less likely to significantly improve VO2 max with training [Limitation] More likely to have lower aerobic capacity [Limitation] Poor endurance running capacity [Advantage] Lower likelihood of weight gain with higher carbohydrate intake [Limitation] Less likely to utilize stored body fat for energy during exercise

Genotype

(Gln27Glu)

Phenotype

[Advantage] More likely to significantly improve VO2 max with training
[Advantage] More likely to have better aerobic capacity
[Advantage] Better endurance running performance
[Limitation] Higher likelihood of weight gain with higher carbohydrate intake
[Advantage] More likely to utilize stored body fat for energy during exercise

Moderate endurance ability and moderate aerobic capacity

[Limitation] Less likely to significantly improve VO2 max with training
[Limitation] More likely to have lower aerobic capacity
[Limitation] Poor endurance running capacity
[Advantage] Lower likelihood of weight gain with higher carbohydrate intake
[Limitation] Less likely to utilize stored body fat for energy during exercise

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How can this information be used?

It is important to choose an appropriate diet based on the genetic profile.[/idea]

For people with A and C variant (Better Endurance Ability)[hr height=”30″ style=”default” line=”default” themecolor=”1″]

Include interval training at high intensities to achieve maximal VO2 training
Likely to respond well to aerobic training and endurance training.

For people with G variant (Low Endurance Ability)[hr height=”30″ style=”default” line=”default” themecolor=”1″]

Likely poor responder to endurance running
Mild improvements in aerobic capacity and endurance performance on carrying out aerobic fitness training can be expected.
Should include moderate amount of carbohydrates in the diet due to increased risk of weight gain on high intake of carbohydrates
Energy restricted diet could result in greater weight loss.

References:[hr height=”30″ style=”default” line=”default” themecolor=”1″]

[idea]Find out which variation of the gene you carry and more at www.www.xcode.in[/idea]

“Nutrigenetics, fitness genetics, health genetics are all nascent but rapidly growing areas within human genetics. The information provided herein is based on preliminary scientific studies and it is to be read and understood in that context.”

Know Your Genes: ADRB2 – “The Adrenaline Gene”