Impact of Polymorphism in the β2-Receptor Gene on the Metabolic Response to Epinephrine After Repeated Hypoglycemia

Abstract

The β2-receptor mediates the metabolic response to epinephrine. This study investigates the impact of the β2-receptor gene (ADRB2) polymorphism Gly16Arg on the metabolic response to epinephrine before and after repetitive hypoglycemia. Twenty-five healthy men selected according to ADRB2 genotype being homozygous for either Gly16 (GG) (n = 12) or Arg16 (AA) (n = 13) participated in 4 trial days (D1–4): D1pre and D4post with epinephrine 0.06 μg kg−1 ⋅ min−1 infusion and D2hypo1–2 and D3hypo3 with three periods of hypoglycemia by an insulin-glucose clamp. At D1pre, the insulin (mean ± SEM of area under the curve 44 ± 8 vs. 93 ± 13 pmol ⋅ L−1 h; P = 0.0051), glycerol (79 ± 12 vs. 115 ± 14 μmol ⋅ L−1 h; P = 0.041), and free fatty acid (724 ± 96 vs. 1,113 ± 140 μmol ⋅ L−1 h; P = 0.033) responses to epinephrine were decreased in AA participants compared with GG participants but without a difference in glucose response. There were no differences in response to epinephrine between genotype groups after repetitive hypoglycemia at D4post. The metabolic substrate response to epinephrine was decreased in AA participants compared with GG participants but without a difference between genotype groups after repetitive hypoglycemia. Article Highlights This study investigates the impact of the β2-receptor gene (ADRB2) polymorphism Gly16Arg on the metabolic response to epinephrine before and after repetitive hypoglycemia. Healthy men homozygous for either Gly16 (n = 12) or Arg16 (n = 13) participated in the study. Healthy people with the Gly16 genotype have increased metabolic response to epinephrine compared with the Arg16 genotype but without a difference between genotypes after repetitive hypoglycemia.