Association of a beta-2 adrenoceptor (ADRB2) gene variant with a blunted in vivo lipolysis and fat oxidation

Abstract

Background and aims: Obesity is associated with a blunted β-adrenoceptor-mediated lipolysis and fat oxidation. We investigated whether polymorphisms in codon 16, 27 and 164 of the β 2- adrenoceptor gene (ADRB2) and exon 10 of the G protein β 3-subunit gene (GNB3) are associated with alterations in in vivo lipolysis and fat oxidation. Design and methods: Sixty-five male and 43 female overweight and obese subjects (body mass index (BMI) range: 26.1-48.4 kg/m 2) were included. Energy expenditure (EE), respiratory quotient (RQ), circulating free fatty acid (FFA) and glycerol levels were determined after stepwise infusion of increasing doses of the non-selective β-agonist isoprenaline (ISO). Results: In women, the Arg16 allele of the ADRB2 gene was associated with a blunted increase in circulating FFA, glycerol and a decreased fat oxidation during ISO stimulation. In men, the Arg16 allele was significantly associated with a blunted increase in FFA but not in glycerol or fat oxidation. Conclusion: These results suggest that genetic variation in the ADRB2 gene is associated with disturbances in in vivo β-adrenoceptor-mediated lipolysis and fat oxidation during β-adrenergic stimulation in overweight and obese subjects; these effects are influenced by gene-gender interactions. © 2007 Nature Publishing Group All rights reserved.