Document Type : Research Paper
Authors
1
Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
2
Department of Genetic, Islamic Azad University, Varamin-Pishva Branch, Varamin, Iran
Abstract
Background and Purpose
Obesity represents a complex, multifactorial condition that increases the risk for non‐communicable diseases. The increasing prevalence of obesity worldwide underscores the need for effective, individualized interventions. Genetic variability plays a crucial role in individual responses to lifestyle interventions, including exercise training. The ADIPOQ gene, encoding the adiponectin hormone, is vital for energy metabolism and fat distribution. The rs266729 polymorphism in the ADIPOQ promoter has been linked to differences in adiponectin levels and metabolic outcomes. This study aimed to compare the body composition response of obese children to an eight‐week exercise training program based on their rs266729 genotype. By stratifying participants according to their genetic profile, we sought to determine whether the presence of the G or C allele influences improvements in weight, body fat percentage, BMI z‐scores, and waist‐to‐hip ratio. Such findings could enhance personalized exercise interventions and improve obesity management effectively.
Materials and Methods
This study involved obese boys aged 11 to 13 years. Initially, 56 participants with a BMI z‐score >2 were recruited after providing informed consent. Based on inclusion and exclusion criteria – excluding those with chronic conditions, regular physical activity, medications affecting growth or nutrition, or endocrine/genetic disorders – 40 participants with diverse rs266729 genotypes were selected. Of these, 30 were assigned to the exercise group and 10 to the control group.
Saliva samples were collected from all participants, and DNA was extracted using the Oragene kit. Primers for the rs266729 region of the ADIPOQ gene were designed with Oligo7 and verified via Primer-BLAST. PCR amplification was conducted under optimized conditions: an initial denaturation at 94°C, 35 cycles of denaturation, annealing at 60°C, and extension at 72°C, followed by a final extension at 72°C. The resulting 250 bp products were digested with the HhaI enzyme at 65°C overnight. Digested fragments were separated on a 2% agarose gel to determine genotype profiles (CC, GC, or GG).
The exercise training program spanned eight weeks, with three sessions per week, each lasting 70 minutes. Sessions included a 5-minute warm-up, 30 minutes of low-intensity aerobic exercise, 30 minutes of resistance training with progressive load adjustments, and a 5-minute cool-down. Anthropometric measurements – weight, height, BMI z-score, waist-to-hip ratio, body fat percentage, and lean mass – were recorded 48 hours before and after the training period using a Tanita body composition analyzer. Data were analyzed with SPSS version 24. Normality was assessed with the Kolmogorov–Smirnov test, and group differences were evaluated using one-way ANOVA and paired t-tests, with p<0.05 considered significant. This rigorous methodology ensured reliable genotyping and accurate assessment of exercise-induced changes in body composition, thereby facilitating the evaluation of genotype-specific responses with precision.
Findings
The intervention resulted in significant improvements in body composition among the obese children undergoing the exercise training program compared to the control group. In the experimental group, post-training measurements demonstrated a significant reduction in body weight, BMI z-scores, body fat percentage, and waist-to-hip ratio, with p-values consistently below 0.05. Notably, the analysis of genotype-specific responses revealed distinct patterns among the rs266729 variants. Participants carrying the GC genotype experienced the greatest reduction in overall body weight and waist-to-hip ratio. In contrast, those with the CC genotype showed the most pronounced decrease in body fat percentage. Although all genotypic groups benefitted from the exercise regimen, the magnitude of change varied, suggesting a modulating effect of the ADIPOQ gene polymorphism on exercise-induced body composition improvements.
The study’s statistical analysis, performed using one-way ANOVA and paired t-tests, confirmed significant training effects within the experimental group, while the control group exhibited no significant changes over the same period. Despite observing significant improvements within each genotype subgroup, the interaction effect between genotype and exercise was not statistically significant for all measured variables, indicating that while the polymorphism may influence the degree of change, it does not completely dictate the overall response to exercise. Moreover, the differential responses observed across genotypes align with previous findings suggesting that the G allele may be associated with less favorable outcomes in terms of adiponectin secretion and metabolic improvements, while the C allele appears to confer benefits by promoting a greater reduction in fat mass and improving metabolic profiles. This is evidenced by the lower body fat percentages observed in CC genotype carriers.
Conclusion
Overall, these findings underscore the importance of considering genetic variability when designing exercise interventions for obesity management. The observed genotype-specific differences highlight the potential for personalized exercise prescriptions based on individual genetic profiles, thereby contributing to more effective intervention strategies. These results support previous research indicating that genetic factors modulate exercise responses and may inform targeted approaches to improve metabolic health in obese populations. The findings thus provide a foundation for future studies exploring genotype-guided exercise interventions.
Further analysis indicated that GC genotype carriers not only lost weight faster but also exhibited earlier improvements in waist-to-hip ratio compared to other genotypes. Although lean mass gains were modest and statistically non-significant, these findings emphasize the potential of rs266729 genotype as a moderator of exercise responsiveness in pediatric obesity, in consistent fashion.
This study demonstrates that an eight‐week exercise training program significantly improves body composition in obese children, with differences observed among rs266729 genotype groups. The GC genotype was associated with greater reductions in body weight and waist-to-hip ratio, whereas the CC genotype was linked to a more pronounced decrease in body fat percentage. Although the interaction between genotype and exercise did not reach statistical significance for all variables, the trends observed suggest that the ADIPOQ rs266729 polymorphism may modulate the magnitude of exercise-induced benefits. These findings support the potential utility of incorporating genetic screening into obesity management protocols to facilitate personalized exercise interventions. By identifying individuals who may respond more favorably to physical activity, clinicians can tailor treatment strategies to optimize metabolic outcomes and reduce obesity-related comorbidities. Overall, the study underscores the importance of genetic factors in mediating exercise responses, supporting individualized approaches in pediatric obesity care. Clinically, results are relevant.
Article Message
This study highlights the critical role of genetic factors in determining the effectiveness of exercise interventions for obesity management. The findings reveal that the ADIPOQ rs266729 polymorphism modulates body composition responses in obese children, with specific genotypes demonstrating varying degrees of weight loss and fat reduction. The results underscore the potential of personalized exercise programs tailored to an individual’s genetic profile, which could enhance therapeutic outcomes and reduce the risk of metabolic disorders. Integrating genetic screening into clinical practice may pave the way for more targeted and effective obesity treatment strategies in pediatric populations, ensuring improved long-term outcomes.
Ethical Considerations
This study was approved by the Ethics Committee of Sport Sciences Research Institute (ethics Code: IR.SSRC.REC.1299.111).
Funding
This study received no funding from public, commercial, or nonprofit organizations.
Authors' Contributions
All authors contributed to the design, implementation, and writing of all parts of the present study.
Conflicts of Interest
The authors declare no conflict of interest.
Acknowledgments
We thank all those who helped us in this study.
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