نوع مقاله : مقاله پژوهشی
نویسندگان
1 استادیار گروه علوم ورزشی، دانشگاه آزاد اسلامی واحد بوئین زهرا، بوئین زهرا، ایران.
2 استادیار گروه علوم ورزشی، دانشکده علوم انسانی، دانشگاه دامغان، دامغان، ایران.
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Extended Abstract
Background and Aim: Cardiovascular diseases are the leading cause of mortality among patients with type 2 diabetes mellitus (T2DM). Chronic hyperglycemia in these patients contributes to myocardial damage, often through the development of atherosclerosis and increased arterial stiffness. Creatine kinase–myocardial band (CK-MB or CK2), an enzyme that catalyzes the transfer of phosphate from phosphocreatine to ADP to regenerate ATP, has been shown to increase approximately six hours after cardiac injury. Additionally, N-terminal pro–B-type natriuretic peptide (NT-proBNP) is recognized as a cardiac neurohormone whose plasma levels rise in patients with ventricular systolic and diastolic dysfunction. This hormone is synthesized in the ventricles and released as proBNP, which is subsequently cleaved enzymatically into NT-proBNP and BNP in response to ventricular myocyte stretch. Rangarz et al. (2019) reported a reduction in BNP levels following eight weeks of resistance training in elderly men, whereas Bordbar et al. (2012) observed a significant increase in BNP after a similar training period. Conversely, other studies have reported no significant changes in BNP levels after 12 weeks of resistance training. Similarly, Saremi et al. (2016) reported elevated CK-MB levels in young women following strength training, and Ghanbari Niaki et al. (2019) demonstrated a significant increase in serum CK-MB after eight weeks of circuit resistance training in sedentary young men. In contrast, Bang et al. (2017) observed no changes in CK-MB levels following eight weeks of resistance training in trained men.
The American Diabetes Association recommends regular physical activity as an effective strategy for managing diabetes-related complications. Researchers believe that regular exercise improves heart muscle function, resulting in adaptation and increased myocardial tolerance to cardiac damage. Resistance training has beneficial effects on the cardiovascular system and may serve as a potential therapeutic approach for patients with cardiac conditions. However, given the possibility of elevated cardiac CK levels following resistance exercise, this training modality has been less extensively investigated. Therefore, the aim of the present study was to investigate the effects of an eight-week resistance training program on serum levels of NT-proBNP and CK-MB in elderly patients with type 2 diabetes by comparing post-intervention values with baseline measurements and with a non-training control group. This investigation may help clarify the safety and cardiovascular implications of resistance training as a lifestyle intervention in this population.
Materials and Methods: This semi-experimental study was conducted on elderly men with T2DM attending the Kahrizak elderly care center in Alborz province (mean age: 71.7±6.6 years; weight: 74.1±13.5 kg; body mass index: 26.7±4.4 kg/m²). Twenty-four participants were randomly assigned to either a control group (no exercise training; n=12) or a training group (resistance training; n=12).
Baseline blood samples were collected one week prior to the intervention after 12 hours of overnight fasting. Post-test samples were obtained at the end of the eight-week intervention, 24 hours after the last training session, and again after 12 hours of fasting. The training group performed resistance exercises for eight weeks, three sessions per week. Each session included 10 minutes of warm-up (jogging or cycling), a main exercise segment consisting of eight movements performed in three sets of 10 repetitions at 70% of one-repetition maximum (1RM), and five minutes of cool-down stretching.
Serum CK-MB levels were measured using a Pars Azmoun kit via the colorimetric method (sensitivity: 5 U/L) with a Hitachi 917 analyzer (Japan). Serum NT-proBNP levels were assessed using the sandwich ELISA method with a Zelbio (Germany) kit (sensitivity: 2.5 ng/L). Statistical analyses were performed using SPSS software (version 24). Analysis of covariance (ANCOVA) was applied to assess between-group differences, with statistical significance set at p≤0.05.
Findings: Serum NT-proBNP levels in the training group decreased significantly following the intervention compared with baseline (F=91.55, p=0.001). In addition, post-intervention NT-proBNP concentrations were significantly lower in the resistance training group than in the control group (F=2.12, p=0.04) (Figure 1A). Serum CK-MB levels also showed a significant reduction in the training group compared with pre-training values (F=20.21, p=0.001). Although CK-MB levels decreased compared with the control group, this change was not statistically significant (F=1.87, p=0.06) (Fig. 1B).
Conclusion: The observed reduction in serum NT-proBNP levels in the resistance training group suggests that exercise-induced increases in myocardial muscle mass may reduce ventricular wall stress, thereby decreasing NT-proBNP secretion. Because BNP production is stimulated by ventricular pressure overload and impaired systolic function, lower circulating levels may reflect improved cardiac performance following resistance training. Although aging and diabetes negatively affect cardiac performance, resistance training may also cause localized muscle damage, potentially involving the sarcolemma, basement membrane, contractile elements, and cytoplasm. Elevated CK-MB, along with CK and cardiac troponins, has been reported as a possible marker of myocardial injury. Factors such as exercise intensity, duration, and prior physical inactivity may influence CK-MB responses. Increases in cardiac workload during exercise, particularly in individuals with compromised health, may lead to ventricular hypertrophy and altered cardiac structure. Some studies have reported significant elevations in CK-MB following resistance training in previously untrained middle-aged men. Although the NT-proBNP improved by resistance training, but it seems that the CK-MB elevation attenuate the prospects for prevention of myocardial infraction. Therefore, it is suggested that with the application of healthy diet and exercise training the greater emphasis should be placed on prevention of diseases such as diabetes.
Compliance with ethical guidelines: The study was approved by the Ethics Committee of Islamic Azad University, Buin Zahra Branch (Ethics code: IRCT20180819040831N1).
Funding: This research received no specific grant from public, commercial, or not-for-profit funding agencies.
Authors contributions: The first author was responsible for study conception, design, data collection, analysis, and manuscript editing. The second author contributed to study conception, design, and manuscript writing.
Conflicts of interest: The authors declare no conflicts of interest.
Acknowledgements: The authors sincerely thank all individuals who contributed to the conduct of this study.
کلیدواژهها [English]
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