Post-exercise oxidative stress and obesity in postmenopausal women: The role of beta₃-adrenergic receptor polymorphism

Abstract

Aim. Some studies indicate that the Trp64Arg polymorphism in the gene encoding the β₃-adrenergic receptor (ADRB3) is associated with obesity, insulin resistance and earlier onset of type 2 diabetes mellitus. The aim of the present study was to evaluate the frequency of this polymorphism and its relationship with obesity and oxidative stress in postmenopausal women.

Material and methods. We performed the study on 200 women, aged 50–60 years. Estimation of anthropometric parameters and total body fat, android and gynoid fat deposits was carried out using dual-energy X-ray absorptiometry. Oxidative stress was estimated by measurement of thiobarbituric acid-reactive substances (TBARS) in serum. Blood for analysis was collected before, directly after and 6 h after a 30-min physical test on a cycle ergometer. ADRB3 genotyping was performed by polymerase chain reaction.

Results. The frequency of Trp⁶⁴/Arg⁶⁴ genotype in the investigated population was 12%, and of Trp⁶⁴/Trp⁶⁴ was 87%. The Arg⁶⁴/Arg⁶⁴ genotype was present in only 1% of women. Women bearing the Trp⁶⁴/Arg⁶⁴ genotype did not differ in any measured anthropometric parameters from women bearing the Trp⁶⁴/Trp⁶⁴ genotype. Moreover, genotype had no influence on oxidative stress parameters. Likewise, in both groups, mean plasma level of TBARS was increased significantly (p < 0.05) directly after the endurance test and remained elevated 6 h after the test.

Conclusions. The Trp64Arg polymorphism of ADRB3 seems to not be related to obesity in postmenopausal women. Moreover, the Trp64Arg polymorphism has no influence on oxidative stress intensification after standardized physical effort in postmenopausal women.

Keywords:

• β₃-Adrenergic receptor
• oxidative stress
• obesity
• postmenopausal women