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Investigation of changes in plasma levels of branched chain amino acids and insulin resistance index after 8 weeks of interval walking in obese girls
Poster Presentation
Paper ID : 1669-11THCONF
Authors
University of Mazandaran
Abstract
Introduction: Levels of plasma branched chain amino acids (BCAAs), including valine, leucine, and isoleucine, are higher in obese than in lean individuals and associated with insulin resistance and predict the onset of type 2 diabetes. The aim of this study was to investigate the changes in plasma levels of BCAAs and insulin resistance index after 8 weeks of interval walking in obese girls.
Methodology: 21 girls (9-11 years old) with a percentile of body mass index (P-BMI) more than 95% participated in this study and were assigned to two groups of exercise (n= 12) and control (n= 9). The exercise group performed an interval walking program for 8 weeks and 3 sessions per week (each session included a 2 minutes walking with 75-85% of HRmax and an active 1-minute rest for 15-30 minutes). Blood samples obtained in 10 hours overnight fasting states prior to the beginning of the training and 72 hours after the last session of the training for measurement of Glucose, Insulin and BCAAs. The BCAAs were measured by high performance liquid chromatography method and the updated HOMA model (HOMA2) were used to evaluate insulin resistance. Paired t-test and independent t-test were used to examine intra-group and inter-group variations, respectively.
Results: After 8 weeks of interval walking, slight weight loss was observed (~1%) which was not statistically significant (p> 0.05), but a significant decrease was observed in the P-BMI (p<0.001), which this was also significant in comparison to the control group (p<0.006). The weight of the control group was significantly increased (p<0.003), and this increase was significant in comparison with the interval walking group (p<0.003). However, no significant change was observed in the P-BMI (p>0.05). Nevertheless, there were no significant changes in plasma levels of leucine, isoleucine, valine, sum of BCAAs and HOMA2 (p>0.05).
Discussion: The protocol used in this study, although it was able to prevent the weight gain of the obese girls, could not be effective in increasing the rate of insulin resistance. Considering that circulating levels of BCAAs are affected by weight reduction, it seems that a reduction in weight of ~1% in this study was not enough to improve the circulation of BCAAs in these obese girls. Exercise-induced factors affecting the changes in the circulating levels of BCAAs require further studies in this regard.
Methodology: 21 girls (9-11 years old) with a percentile of body mass index (P-BMI) more than 95% participated in this study and were assigned to two groups of exercise (n= 12) and control (n= 9). The exercise group performed an interval walking program for 8 weeks and 3 sessions per week (each session included a 2 minutes walking with 75-85% of HRmax and an active 1-minute rest for 15-30 minutes). Blood samples obtained in 10 hours overnight fasting states prior to the beginning of the training and 72 hours after the last session of the training for measurement of Glucose, Insulin and BCAAs. The BCAAs were measured by high performance liquid chromatography method and the updated HOMA model (HOMA2) were used to evaluate insulin resistance. Paired t-test and independent t-test were used to examine intra-group and inter-group variations, respectively.
Results: After 8 weeks of interval walking, slight weight loss was observed (~1%) which was not statistically significant (p> 0.05), but a significant decrease was observed in the P-BMI (p<0.001), which this was also significant in comparison to the control group (p<0.006). The weight of the control group was significantly increased (p<0.003), and this increase was significant in comparison with the interval walking group (p<0.003). However, no significant change was observed in the P-BMI (p>0.05). Nevertheless, there were no significant changes in plasma levels of leucine, isoleucine, valine, sum of BCAAs and HOMA2 (p>0.05).
Discussion: The protocol used in this study, although it was able to prevent the weight gain of the obese girls, could not be effective in increasing the rate of insulin resistance. Considering that circulating levels of BCAAs are affected by weight reduction, it seems that a reduction in weight of ~1% in this study was not enough to improve the circulation of BCAAs in these obese girls. Exercise-induced factors affecting the changes in the circulating levels of BCAAs require further studies in this regard.
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