The effects of β₂ adrenoceptor gene polymorphisms on pressor response during laryngoscopy and tracheal intubation

We investigated whether human β₂ adrenoceptor (β₂AR) gene polymorphisms are associated with the pressor response to laryngoscopy and tracheal intubation. Ninety-two patients undergoing elective surgery under general anaesthesia were enrolled into this study. Arterial systolic pressure, heart rate and rate pressure product were measured before induction of anaesthesia and 1 min following laryngoscopy and tracheal intubation. Genomic DNA was then used to identify the β₂AR-16 and β₂AR-27 genes using an allele-specific polymerase chain reaction method. Using multiple linear regression models, controlling for age, sex, weight, baseline blood pressure, heart rate and rate pressure product, we found that patients who possessed the glutamic acid homozygote of β₂AR-27 produced significantly greater changes in mean arterial pressure and rate pressure products than patients with the glutamine homozygote of β₂AR-27 (β coefficient for mean blood pressure = 11.81, β coefficient for pulse-pressure product = 8.76, both p-values = 0.023). These findings suggest that genetic variability in the human β₂AR gene polymorphisms may be associated with the pressor response to laryngoscopy and tracheal intubation.