نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشجوی دکتری فیزیولوژی ورزشی، گروه تربیت بدنی و علوم ورزشی، واحد نیشابور، دانشگاه آزاد اسلامی، نیشابور، ایران.
2 استاد گروه فیزیولوژی ورزشی، دانشکده علوم ورزشی، دانشگاه فردوسی مشهد، مشهد، ایران.
3 استادیار گروه تربیت بدنی و علوم ورزشی، واحد نیشابور، دانشگاه آزاد اسلامی، نیشابور، ایران.
چکیده
کلیدواژه‌ها
عنوان مقاله [English]
نویسندگان [English]
Extended Abstract
Background and Aim: Cardiovascular diseases (CVDs) remain among the leading causes of mortality worldwide, with coronary artery disease (CAD) playing a significant role (2, 3). CAD occurs due to the narrowing or blockage of coronary arteries caused by atherosclerosis, which results from lipid accumulation and blood clot formation, potentially leading to myocardial infarction. Coronary artery bypass grafting (CABG) surgery is a widely used treatment to improve myocardial blood flow; however, the risk of recurrent atherosclerosis remains.
Key risk factors for CAD include elevated total cholesterol (TC) and low-density lipoprotein (LDL) levels, along with reduced high-density lipoprotein (HDL) (4). Additionally, apolipoprotein B (ApoB) is a crucial atherogenic marker that plays a fundamental role in atherosclerosis progression (11). Research suggests that physical exercise, particularly endurance training, has a beneficial impact on reducing ApoB levels and improving lipid profiles. However, some studies have reported conflicting results (12). Given these inconsistencies, this study aims to investigate the effects of combined aerobic-resistance training on lipid profile, ApoB levels, and atherogenic indices in middle-aged men following CABG surgery.
Materials and Methods: This study employed a quasi-experimental pre test-post test design with a control group. The statistical population comprised of men aged 50–65 years who had undergone CABG surgery within the past year. Based on G*Power software calculations, with a 95% confidence level and 80% statistical power, 22 participants were initially selected. To account for potential dropouts, the final sample size was increased to 25. After obtaining ethical approval and clinical trial registration, participants (mean age: 56 ± 3.8 years; weight: 75 ± 7.13 kg) were purposively selected from patients based on inclusion criteria, including cognitive health, absence of movement restrictions, body mass index (BMI) between 25–30 kg/m², and no use of non-specific medications. Participants were then randomly assigned to an exercise group (n= 14) and a control group (n= 11). The intervention consisted of an eight-week combined training program (aerobic-resistance), performed three times per week. Aerobic exercises included treadmill walking (20–30 min), cycling on an ergometer (10–12 min), and hand cycling (10 min). Exercise intensity was progressively increased based on the Borg scale and heart rate reserve, starting at 55% and reaching 80% during the final ten sessions. The resistance training component involved selected exercises using TheraBand resistance bands, beginning with low resistance and gradually increasing repetitions (from 8 to 15), followed by progressive resistance increments. All exercises were supervised by a cardiologist and a sports medicine specialist. Before and after the intervention, body composition, blood pressure, heart rate, and dietary intake were assessed. Fasting blood samples were collected, and plasma levels of ApoB, LDL, HDL, and TC were measured using ELISA and enzymatic methods. Data analysis was conducted using SPSS version 21 with repeated-measures ANOVA, considering a significance level of p<0.05.
Finding: The findings demonstrated that combined aerobic-resistance training significantly improved several lipid profile and atherogenic indices in CABG patients. Statistical analysis revealed significant between-group differences in plasma levels of TC (p=0.01, F=7.15), HDL (p=0.01, F=6.35), LDL/HDL ratio (p=0.02, F=5.86), and atherogenic index (TC - HDL/HDL) (p=0.001, F=13.87). Specifically, the eight-week intervention led to a significant reduction in TC (3.95%), LDL/HDL ratio (8.19%), and atherogenic index (14.28%), along with a significant increase in HDL (6.87%). However, the between-group differences in LDL levels were not statistically significant (p=0.15, F=2.21). Additionally, significant changes were observed in plasma ApoB levels (p=0.01, F=6.90), with a significant reduction of 4.4% in the training group (p=0.005, F=11.11). Furthermore, significant reductions were observed in body weight (p=0.004, F=10.39), body fat mass (p=0.02, F=5.12), and BMI (p=0.004, F=10.27). Specifically, the intervention led to a significant decrease in body weight (1.46%), fat mass (10.85%), and BMI (1.45%) in the exercise group.
Conclusion: The results suggest that reducing ApoB levels may serve as a more reliable indicator than LDL for assessing CVD risk, as ApoB reflects the number of LDL particles and has a stronger association with atherosclerosis. Previous studies, such as those by Jafari et al. (2018) and Mozzella et al. (2020), have confirmed a reduction in ApoB following exercise interventions. In contrast, other studies (Azizi et al., 2016; Behr et al., 2010) have reported no significant changes in ApoB, possibly due to variations in exercise intensity and duration. The reduction in atherogenic indices observed in this study suggests that combined training effectively improves lipid profiles. Notably, the LDL/HDL ratio, a strong predictor of CVD risk, significantly decreased. While some previous studies support these findings, others suggest that the effectiveness of exercise on lipid profiles depends on factors such as training intensity, diet, and individual participant characteristics.
The findings of this study indicate that an eight-week combined aerobic-resistance training program exerts a beneficial effect on lipid profiles, plasma ApoB levels, and atherogenic indices in middle-aged men following CABG surgery. The reduction in TC, LDL/HDL ratio, and atherogenic index, along with the increase in HDL, reinforces the positive impact of such training on cardiovascular health. Moreover, the significant reduction in ApoB, despite no significant change in LDL levels, highlights the potential of ApoB as a more precise and reliable marker for CVD risk assessment. Improvements in body composition, including reductions in body weight and fat mass, further confirm the positive role of physical activity in managing metabolic risk factors. Therefore, incorporating combined aerobic-resistance training into cardiac rehabilitation programs is recommended to enhance cardiovascular function and prevent recurrent atherosclerosis. Future research should focus on investigating the long-term effects of such training interventions.
Keywords: Exercise training, Apolipoprotein B, Lipid profile, Coronary artery bypass grafting
Ethical Considerations
All ethical principles in this research were meticulously adhered to by the researchers.
Compliance with ethical guideline
To conduct the research, the consent form was completed by the participants after they were fully informed about the research process, including its risks and benefits.
Funding
The authors of this article declare that they have not received any financial support from any organization.
Conflicts of interest
The authors report no conflicts of interest in relation to this manuscript.
کلیدواژه‌ها [English]
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