Visfatin Genotypes Influence Glucose And Obesity-related Variables And Their Aerobic Exercise Training Responses

Abstract

Previous research has linked the proposed adipokine visfatin and its gene (PBEF1) polymorphisms with glucose and obesity-related conditions; however, no one has examined them in connection with aerobic exercise training in generally healthy older individuals. PURPOSE: To determine whether PBEF1 polymorphisms are associated with the response of glucose and obesity-related variables to aerobic exercise training. METHODS: Following the completion of 6 wks of dietary stabilization, 116 healthy, sedentary, middle-aged, Caucasian men and women underwent 24 wks of aerobic exercise training. DEXA was used to assess body composition, and oral glucose tolerance testing was used to determine glucose and insulin response variables, including total area under the curve (AUC) and insulin sensitivity (IS), before and after 6 months of aerobic exercise training. TaqMan and RFLP assays were used to determine PBEF1 genotypes, and ANCOVA was used to test for differences between genotype groups. RESULTS: There were several associations at baseline between glucose and obesity-related variables and the PBEF1 polymorphisms. The -4689 (rs2110385) TT genotype group had lower insulin AUC (p < 0.01) and higher IS (p < 0.02) values than the GG genotype group, whereas PBEF1 -1001 (rs9770242) G allele carriers had lower fasting insulin (p < 0.03), lower body mass index (BMI; p < 0.02), and higher IS values than the TT genotype group (p = 0.04). Additionally, the -948 T allele carriers group had lower glucose AUC (p = 0.03), lower insulin AUC (p < 0.02), and higher IS values than the GG genotype group (p < 0.02). Finally, the SER301SER (rs2302559) TT genotype group had lower fasting insulin (p < 0.02), lower insulin AUC (p < 0.01), and higher IS (p < 0.01) values than the CC genotype group. The SER301SER polymorphism also influenced aerobic exercise training-induced changes in percent body fat (p < 0.02) and BMI (p = 0.03). CONCLUSIONS: Our results suggest that variation at the PBEF1 locus is associated with baseline and aerobic exercise training-induced changes in glucose and obesity-related variables. Future studies need to address the physiological mechanisms and functional significance of visfatin polymorphic variation.