ADRB2 Arg16Gly (rs1042713): Adrenaline Response

The ADRB2 gene encodes the beta-2 adrenergic receptor, which mediates responses to adrenaline (epinephrine) and noradrenaline throughout your body. The Arg16Gly variant (rs1042713) affects receptor function with implications for asthma, fat metabolism, blood pressure, and athletic performance.

What is ADRB2?

Beta-2 adrenergic receptors are found throughout the body and mediate key responses to catecholamines:

• Lungs: Bronchodilation (airway opening)
• Fat tissue: Lipolysis (fat breakdown)
• Heart: Increased contractility and rate
• Blood vessels: Vasodilation
• Muscle: Glycogenolysis and enhanced performance

Beta-2 agonist medications (like albuterol for asthma) work by activating these receptors.

Understanding Your Genotype

• Arg/Arg (GG): Receptors more resistant to downregulation
• Arg/Gly (GA): Intermediate characteristics
• Gly/Gly (AA): Receptors more prone to downregulation with chronic stimulation

Asthma and Respiratory Effects

Response to Beta-Agonist Medications

• Gly16 (AA): May show stronger initial response to beta-agonists but faster receptor desensitization with regular use
• Arg16 (GG): More stable receptor function with chronic treatment
• May influence which treatment regimens work best

Asthma Severity

• Some studies associate Gly16 with increased asthma severity
• May influence nocturnal asthma symptoms
• Findings are population-specific and not entirely consistent

Metabolism and Weight

Fat Metabolism

• Beta-2 receptors mediate adrenaline-induced fat breakdown
• Gly16 associated with higher lipolysis rate in some studies
• May influence response to exercise for fat loss
• Caffeine and other stimulants work partly through this pathway

Obesity Risk

• Some studies show Gly16 associated with higher obesity risk in women
• May interact with dietary factors
• Effects are modest and inconsistent across populations

Athletic Performance

• Beta-2 receptors affect muscle glucose uptake and blood flow
• May influence response to endurance training
• Some studies show Gly16 more common in endurance athletes
• Effects on performance are subtle compared to training factors

Cardiovascular Effects

• ADRB2 variants may influence blood pressure response to stress
• May affect heart rate variability
• Response to beta-blocker medications may differ by genotype

Prevalence

• European ancestry: Gly16 allele frequency approximately 40%
• African ancestry: Higher Gly16 frequency (approximately 50%)
• East Asian: Lower Gly16 frequency (approximately 35%)

Practical Implications

For Asthma Management

• If you have Gly/Gly and use regular beta-agonists, discuss with your doctor if medication seems less effective over time
• Inhaled corticosteroids may be particularly important for Gly16 carriers

For Weight Management

• Exercise that elevates catecholamines may be particularly effective
• Caffeine may enhance fat oxidation differently based on genotype

Testing with NutraHacker

NutraHacker analyzes ADRB2 along with other genes affecting metabolism and fitness.

References

1. Green SA, et al. Amino-terminal polymorphisms of the human beta 2-adrenergic receptor impart distinct agonist-promoted regulatory properties. Biochemistry. 1994;33(32):9414-9419.
2. Liggett SB. Polymorphisms of the beta2-adrenergic receptor and asthma. Am J Respir Crit Care Med. 1997;156(4 Pt 2):S156-162.
3. Meirhaeghe A, et al. A genetic polymorphism of the beta 2-adrenergic receptor gene and body mass index. Int J Obes Relat Metab Disord. 1999;23(10):1099-1100.