نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشیار گروه فیزیولوژی ورزشی، دانشکده علوم تربیتی و روانشناسی، دانشگاه شهید مدنی آذربایجان، تبریز، ایران.
2 دانشیار مرکز تحقیقات طب فیزیکی و توانبخشی، دانشگاه علوم پزشکی تبریز، تبریز، ایران.
3 دانشجوی کارشناسی ارشد فیزیولوژی ورزشی، دانشکده علوم تربیتی و روانشناسی، دانشگاه شهید مدنی آذربایجان، تبریز، ایران.
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Extended Abstract
Background and Aim: Osteopenia is a metabolic bone disorder could precedes osteoporosis. The balance of some macroelements such as— calcium, magnesium and phosphorus — are crucial for the growth and metabolism of bone tissue. Their concentration and distribution could influenced by biological and environmental factors such as gender, age, diet, living environment, smoking, alcohol consumption and chronic diseases. In addition, exercise affects plasma calcium and phosphorus levels and bone metabolism. Some studies have shown that 8 weeks of aerobic exercise can increase serum calcium and phosphorus levels in women with premature menopause. Moreover, 12 weeks of aerobic exercise significantly improves serum free calcium levels, while 12 weeks of strength training also can increase serum phosphorus levels. However, a decrease or no change in serum magnesium levels has been reported as a result of long-term training. Given the limited studies on the long-term effects of exercise training and the conflicting results regarding magnesium, it would be crucial more research on the effects of combined training (CT) in ling duration and interventions such as electrical stimulation (ECT) to enhance their synergistic effects.
Materials & Methods: In this quasi-experimental study, 45 women with an average age of 61.25±1.4 years and osteopenia state (T-score < -1 and > -2.5) were randomly selected and further divided into 3 equal groups including ECT, CT and control groups. Both ECT and CT groups performed a combination of aerobic (45-60 percent of heart rate reserve) and resistance training (3 sets of 8-15 repetitions, 5-10 stations using body weight, physioball, and yellow resistance band) for 90 minutes per session, 3 days a week for 12 weeks. The exercise training was performed in accordance with the American College of Sports Medicine (ACSM) guidelines for patients with osteopenia. In addition, during 12 weeks participating in exercise program from weeks 7 to 10, the ECT group also received functional electrical stimulation (FES). The FES performed 3 times a week with supervision of a rehabilitation physician for 25 minutes at a frequency of 45 Hz and a pulse of 300 microseconds using the STIMULATOR 620 P (NOVIN) device in the paraspinal area. According to the reports of the review studies, the duration of FES sessions can be ranged from 2 minutes to 6 hours, its frequency or frequency ranged from 2 to 7 sessions per week, and its duration ranged from 2 to 12 weeks with a total intervention dose ranging from 5 to 90 hours, and the ECT frequency also ranged from 25 to 50 Hz and the pulse width ranged from 200 to 400 microseconds. The exercise protocol was started 48 hours after blood sampling, and in the post-test 48 hours after the completion of the 12 weeks exercise program, assessments and blood sampling were performed according to the pre-test. Calcium, magnesium, and phosphorus were measured based on the calorimetric method commercial using by Arsenazo III, Xylidy Blue, and phosphomolybdate kits from Delta Darman Part Company, respectively. Cortisol was measured using electrochemiluminescence technology and using the Cobas e411 device (made in Germany-Japan). Data were analyzed using a mixed‑design ANOVA, and statistical significance was defined as p<0.05
Findings: Serum calcium and phosphorus levels showed no significant differences within or between groups (p<0.05). However, serum magnesium levels in the ECT group indicated significantly increase compared to the control group (p=0.01). Additionally, cortisol levels decreased in both intervention groups compared to the control group (p<0.05) (Table 1). Moreover, analysis of the relationship between changes in cortisol and ion levels after 12 weeks of CT and ECT revealed a significant negative correlation between these changes in cortisol and magnesium (r=-0.66, p=0.01). Linear regression also indicated that changes in magnesium levels could be predicted based on changes in cortisol levels (R²=44.4%, t=(12 and 1)-2.96, p=0.01).
Conclusions: The results indicated that 12 weeks CT program (aerobic resistance) in conjunction with FES (as a safe and complementary exercise therapy) was effective in increasing serum magnesium levels, that suggests a synergistic effect of ECT in increasing magnesium levels in older women with osteopenia. Although, researches on the effects of exercise and ECT on serum magnesium levels, particularly in the elderly, are limited, and also based on the short-term and long-term exercise on magnesium levels could be very vary, however, short-term exercise as a stressor may result in a transient decrease in serum magnesium levels, usually due to increased magnesium consumption by muscles, redistribution in tissues, or loss through sweat and urine. Serum magnesium levels have been reported to decrease due to a sudden increase in catecholamine concentration following electrical stimulation. However, with regular and long-term exercise training, this type of intervention can help stabilize or improve magnesium homeostasis due to improved dietary patterns, better absorption, storage of magnesium, and also changes in levels of hormones such as catecholamines and aldosterone. Studies have shown that stress can increase magnesium loss and consequently magnesium deficiency. Cortisol, as a mediator of the stress response, affects magnesium levels. The results of this study showed a significant correlation between the changes in cortisol and magnesium in the exercise group in combination with ECT. The reduction in cortisol can be considered as one of the reasons for the increase in serum magnesium levels after exercise and ECT. Moreover, the positive effects of long-term exercise training on lowering serum cortisol and the fact that physical activity may be an effective strategy for reducing cortisol and stress, especially in older people. Although, there are some inconsistent studies, however, the discrepancy in results may be due to differences in age or gender of subjects, type or mode and duration of exercise, and psychological conditions such as stress at the time of blood collection. These results suggest that FES synergistically increases magnesium levels, while reducing serum cortisol can be effective in this increase. It seems, further research is needed based on the optimal intensity, duration, and type of interventions to enhance the effect on calcium and phosphorus ions. In agreement with the present findings and previous reports (Guo S., 2022; Roghani, 2013), exercise training and ES did not significantly affect serum calcium and phosphorus levels in women. Considering the stringent hormonal and renal regulation of these minerals, such interventions either alone or even in combination—may be insufficient to elicit measurable biochemical alterations. Therefore, further well-controlled trials employing refined protocols and comprehensive physiological assessments are warranted.
Ethical considerations: Before starting the protocol, informed consent forms were signed by the subjects and ethics ID IR.AZARUNIV.REC.1402.010 was obtained.
Conflict of interest: There are no conflicts of interest.
Compliance with ethical guideline: The study was conducted in accordance with all applicable institutional and national ethical guidelines. Ethical approval was obtained from the relevant ethics committee, and written informed consent was collected from all participants.
Funding: No funding was received for this study. The author personally covered all research-related costs.
کلیدواژهها [English]
)