1. Introduction

oronary heart disease is one of the leading causes of death in today’s society [1]. Patients with myocardial infarction and those who have undergone surgery, despite the improvement of the symptoms of the disease and the relative increase in life expectancy, suffer from problems such as insufficient useful life, multiple hospitalizations, and psychological and social problems. Accordingly, some researchers suggest different exercises to improve the quality of life and increase the functional capacity of these patients [2]. 

In the study of Banerjee et al. it was reported that exercise capacity is the strongest predictor of deaths caused by cardiovascular events [3, 4]. This study has also shown that muscle strength and functional capacity are reduced in heart patients. Due to its attractiveness and low cost, exercise can be an incentive for patients to participate in (cardiac) rehabilitation programs and can be used in the form of multidisciplinary programs to increase mental health, functional capacity and quality of life of cardiovascular patients [5]. The aim of this study was to evaluate the effect of eight weeks of resistance-aerobic training on endostatin levels in patients with Coronary Artery Bypass Grafting (CABG).

2. Materials and Methods

The participants of this study consisted of 24 male patients with a mean age of 55.37±6.90 years, weight 75.45±5.87 kg, height 173.27±3.36 cm, and body mass index 1.55±25.11 kg/sq (Table 1), who were randomly divided into experimental (n=12) and control (n=12) groups.



According to the assessments (cardiopulmonary status and exercise tolerance test), the experimental group performed eight weeks of resistance-aerobic exercise for one to one and a half hours (3 sessions per week) and the control group was without exercise during this period. To measure endostatin levels, blood samples were taken 48 hours before the start of the protocol and also 48 hours after the last session of the protocol while all subjects were fasting (Table 2). For data analysis, Shapiro-Wilk test was used to normalize the data and Student’s t-test was used in independent and correlated groups at a significance level of 0.05.


 

3. Results 

The normality of the data was evaluated using Shapiro-Wilk test. Data analysis in correlated and dependent groups was performed by paired-sample t-tests using SPSS V. 21 at a significant level of P≤0.05.

The results showed that in the aerobic-resistance exercise group, a significant decrease was observed in endostatin levels (P=0.001) (T=1.672) compared to the control group (Table 3).



Also, paired-sample t-test data based on the pre-test and post-test measurements in the experimental group showed a significant decrease in endostatin levels (P=0.001) (T=7.883) (Figure 1).


 

4. Discussion and Conclusion

One of the most important anti-angiogenic factors of endostatin is that according to the results of many studies, this variable is affected by sports activities [31-37]. Studies show that endurance exercise increases the shear stress of bloodstream, increases the activity of endothelial nitric oxide synthetase and increases the antioxidant capacity, which has positive effects on endothelial function, especially in cardiovascular patients [32-34]. Brixius et al. (2008) reported that endostatin levels decreased in response to prolonged aerobic activity in obese men [45]. 

Suhr et al. (2010) showed that six months of endurance activity significantly reduced endostatin levels in male runners [46]. Rullman et al. (2007) showed that one session of resistance exercise had no effect on reducing endostatin [48]. The lack of discrepancy between their results and the results of the present study may be due to the dissimilarity of the subjects, exercises and duration of the research. The mechanism of endostatin reduction in response to exercise is not yet known, but it is possible that exercise reduces the rate of metamorphosis in the extracellular matrix, which may prevent endostatin from dissociating from collagen [49].

According to the results of this study, which examined the effect of eight weeks of resistance-aerobic exercise on anti-angiogenic factors, it was found that these exercises increased blood supply to the myositis due to increased angiogenic factors and also by reducing anti-angiogenic agents in the bloodstream had a significant effect on reducing the complications of cardiovascular disease. Also, according to the results of the research consistent with the present study, it is suggested that in patients with cardiovascular disease and CABG patients, exercise along with other clinical therapies - as a non-pharmacological method and efficient prevention - should be considered.

Ethical Considerations

Compliance with ethical guidelines

This article was ethically approved by Azad University of Neyshabur  (Ethics Code IR.IAU.NEYSHABUR.REC.1398.018) and with the Clinical Trial Code IRCT20191228045916N1 in the Iranian Registry of Clinical Trials.

Funding

The paper was extracted from the  PhD.  dissertation of the first author, Department of Physical Education & Sport Sciences, Neyshabour Branch, Islamic Azad University, Neyshabour. 

Authors' contributions

Conceptualization, research method, sampling and drafting: Seyed Hadi Seyedi; Data analysis: Rambod Khajei, Amir Rashid Lamir; Editing and finalization: All authors.

Conflicts of interest

The authors declared no conflicts of interest.

Acknowledgements

The authors of this article would like to thank the participants and those who helped in this research, as well as the cardiac rehabilitation department of Javad Al-Aeme Hospital in Mashhad City.