|Year : 2023 | Volume
| Issue : 1 | Page : 1-6
Effect of acute exercise on Cardiovascular and Serum cortisol reactivity to mental stress in offspring of hypertensives
Pooja Sardar Nigade1, VP Varshney1, Mona Bedi2
1 Department of Biochemistry, Maulana Azad Medical College, And associated hospitals, New Delhi, India
2 Department of Physiology, Maulana Azad Medical College, New Delhi, India
|Date of Submission||06-Jan-2023|
|Date of Acceptance||28-Mar-2023|
|Date of Web Publication||28-Apr-2023|
MBBS, MD, DNB Physiology Pooja Sardar Nigade
Senior resident, Department of Physiology, Maulana Azad Medical College, And associated hospitals. New Delhi – 110002
Source of Support: None, Conflict of Interest: None
Introduction: The purpose of our study was to evaluate the effect of acute exercise on HR, BP and serum cortisol levels in offspring of hypertensives. This could serve as a preventive measure to habituate the high risk population group right at the early age. Material and Methods: The study was a double blind single centered randomized controlled prospective study conducted in the Department of Physiology & Biochemistry, Maulana Azad Medical College and associated hospitals, New Delhi over a period of 1 year. 30 subjects were recruited for the study. They were labelled as:- Group 1–the subjects were rested for 10 minutes after which the measurement of BP, HR and Serum cortisol was done. This resting value was labeled as R-1. The subjects were then exposed to mental arithmetic test (MAT) for 5 minutes. Thereafter their BP, HR and Serum Cortisol were measured again and labeled as T-1. Group 2–Same subjects were similarly rested for 10 minutes after which the measurement of BP, HR and S. cortisol was done. This resting value was labeled as R-2. This was followed by 20 minutes of Bicycle ergometry exercise. The subjects were then exposed to MAT for 5 minutes. Thereafter their BP, HR and Serum cortisol were measured again and labeled as T-2. We then compared (T2–R2) known as Cardio-Adrenal Reactivity (CAR) with exercise vs CAR without exercise (T1-R1). 2ml of blood sample was withdrawn for estimation S. cortisol. Paired t-test was applied for comparison (p value <0.05–significant). Results: The CAR was more in Group 1 compared to Group 2, difference being statistically significant. Conclusion: Study showed statistically significant change between with and without exercise groups. Acute exercise can reduce the adrenocortical reactivity to stress, a preventive tool for development of future hypertension.
Keywords: Cardio-adrenal reactivity, Mental arithmetic test, Offspring of hypertensive, Bicycle ergometry, Acute exercise
|How to cite this article:|
Nigade PS, Varshney V, Bedi M. Effect of acute exercise on Cardiovascular and Serum cortisol reactivity to mental stress in offspring of hypertensives. MAMC J Med Sci 2023;9:1-6
|How to cite this URL:|
Nigade PS, Varshney V, Bedi M. Effect of acute exercise on Cardiovascular and Serum cortisol reactivity to mental stress in offspring of hypertensives. MAMC J Med Sci [serial online] 2023 [cited 2023 Jun 4];9:1-6. Available from: https://www.mamcjms.in/text.asp?2023/9/1/1/375331
| Introduction|| |
Essential hypertension has proven to be a common comorbidity not only in old age but also in younger population in today’s era. It has been suggested that if either of the parents is hypertensive then there is a 25% risk among their children to develop hypertension. Furthermore, the same risk soars to 50% when both the parents are hypertensive. Physical activity and exercise ameliorates both the emotional and cognitive health that are negatively impacted by stress, an inevitable adjunct in today’s lifestyle. Such stressors have been found to be associated with increase in cardiovascular and serum cortisol reactivity, thereby serving as a surrogate to the level of stressor. Studies have elucidated that regular exercise can habituate or sensitize the body to such stressors thereby serving as an important tool to reduce the same. The purpose of our study was to evaluate the effect of acute exercise on HR, BP and serum cortisol levels in offspring of hypertensives. The changes in HR, BP and S. cortisol in the offspring of hypertensives as compared to those of normotensives will help in predicting development of hypertension in future. This could serve as a preventive measure to habituate the high risk population group right at the early age.
| Material and Methods|| |
The study was a double blind single centered randomized controlled prospective study conducted in the Department of Physiology in association with the Department of Biochemistry, Maulana Azad Medical College and associated hospitals, New Delhi over a period of 1 year (November 2018 to November 2019). Clearance from the Ethics Committee was taken for the prior to initiation of the study and the necessary guidelines were followed. Since human subjects were used, study was done in accordance with the principles of Declaration of Helsinki. We included 30 subject volunteers who were offsprings of hypertensive parents (either one or both having a known history of Essential hypertension) selected from nearby communities aged 18-21 years with normal BMI (18.5-25kg/m2) ([Table 1]). Women were tested during menstrual cycle days 3-8 to minimize potential gender differences in cardio-vascular reactivity during stress. 21 Subjects with BMI >25kg/m2, history of hypertension or co-morbid conditions like endocrinal disorders, cardiovascular, respiratory, musculoskeletal, neurological, psychological abnormalities, etc., chronic alcoholics, tobacco or drug abusers were excluded from the study. The primary objective of the study was to evaluate the effect of acute bout of exercise on serum cortisol levels in non-hypertensive offspring of hypertensives when exposed to mental stress. The secondary objective was to use the results as a tool to detect subjects who are prone to develop hypertension hence taking preventive measures. The subjects were asked to refrain from tea, coffee, chocolates and ice-cream at least 12 hours prior to testing. Resting BP and HR were measured using a cardiac monitor (BIOPAC model). Ambient room temperature was maintained to avoid the effect of temperature on HR, BP and S. Cortisol during the test and exercise (temperature effect). Proper history taking and general physical examination was done. The 30 subjects (Male: Female = 15:15) meeting the above criteria were recruited for the study (done in the morning at around 8 am) after taking proper consent. They were labelled as :-
Group 1 (Pre-exercise group): The subjects performing MAT without exercise. Group 2 (Post-exercise group): The same subjects performing MAT after exercise. ([Figure 1],[Figure 2],[Figure 3])
Group 1–the subjects were rested (seated upright) for 10 minutes after which the measurement of BP, HR and Serum cortisol was done. This resting value was labeled as R-1. The subjects were then exposed to mental arithmetic test (MAT) for 5 minutes. During the MAT, subjects were asked to serially subtract 17 from a four-digit prime number (2479) at planned intervals and were asked to do the calculation in their mind. They were made to say the answer as fast as possible trying to keep pace with a metronome that was making a sound at every 30 seconds. The serial calculations had to be done continuously for 5 minutes. Thereafter their BP, Heart Rate and Serum Cortisol were measured again and labeled as T-1.
Group 2 − The subjects were similarly rested (seated upright) for 10 minutes after which the measurement of BP, Heart Rate and S. cortisol was done. This resting value was labeled as R-2. This was followed by 20 minutes of Bicycle ergometry exercise. The intensity of exercise was adjusted at 60%- 70% of maximal HR as calculated according to WHO formula (220–Age in years). This was followed by 30 minutes of rest (seated upright). The subjects were then exposed to mental arithmetic test for 5 minutes. Thereafter their BP, Heart Rate and Serum cortisol were measured again and labeled as T-2. We then compared (T2–R2) known as Cardio-Adrenal Reactivity (CAR) with exercise vs CAR without exercise (T1-R1).
Blood test: Two ml of blood sample was withdrawn for estimation S. cortisol. The serum was separated by centrifugation at room temperature at the rate of 3000 revolutions per minute after which it was stored at −80°C. Quantitative determination of Serum Cortisol was done by Electro-chemiluminescence based immunoassay (ECLIA) method done on ‘Elecsys’ immunoassay (cobas e 411) analyzers based on “Competitive principle”. Total duration of assay was around 18 minutes. Normal values of serum cortisol by this method: Morning hours (7–10 AM): 171–536 nmol/L. Statistical analysis: It was done using statistical package for social sciences (SPSS- software version 25). Paired t-test was applied for comparison and p value <0.05 was considered significant.
| Observations and Results|| |
CARDIOADRENAL REACTIVITY (CAR): The CAR was more in Group 1 compared to Group 2 and the difference was statistically significant [Table 2] and [Table 3].
| Discussion|| |
In this fast-paced 20th century stress is inevitable, therefore the people are bound to face many challenges or stress- either mental, physical or psychological, which can lead to various physiological adaptations to cope up. There are studies indicating that children of hypertensive parents tend to exhibit high stress reactivity influenced by both genetic and environmental factors.
An important factor for hypertension is increased activity of HPA axis (Hypothalamo-Pituitary- Adrenal Axis). When a person is exposed to stressful situation HPA axis gets activated, leading to stimulation of adrenal cortex and release of cortisol into blood. Increase in the level of various stress hormones, especially cortisol is responsible for the various physiological reactions to stress i.e. fight or flight response. Serum cortisol has a permissive role in maintaining cardiovascular reactivity, hence promoting hypertension. Cortisol increases renal plasma flow, and glomerular filtration rate from the kidneys thus increasing sodium and water retention leading to hypervolemia thus, resulting in hypertension.
Previous reactivity studies in this area have solely focused on BP and HR responses to stress. A fewer studies have examined Cortisol secretion in response to stress in hypertensives and persons at risk for hypertension. In a study by Kirschbaum C et al., significant positive correlation was found between adrenocortical stress response and repeated psychological stress. To date, there is paucity of data correlating adrenocortical reactivity to mental stress and their relation to the development of cardiovascular diseases later. Most of the studies in the past have been done in hypertensive patients themselves and not in their offspring.
In our study, the adrenocortical reactivity (ACR) was calculated by measuring the change in serum cortisol value between the baseline and after the completion of mental arithmetic stress test. It was found that serum cortisol levels are increased after exposure to MAT. Further it was observed that serum cortisol reactivity was attenuated after exposure to acute bout of exercise. The mean ± S.D. values for change in serum cortisol is significantly higher in the Group 1 (ACR to MAT Pre-exercise) than that in the Group 2 (ACR to MAT post-exercise), implying that acute bout of exercise has significantly decrease ACR in the children of hypertensive parents. This finding is in close agreement with M. al’Absi et al. who proposed that Cortisol responses to mental stress are more persistent and greater in persons at high risk for hypertension i.e. offspring of hypertensive parent relative to low risk normotensives. This is because of the fact that several BP related changes are affected by Serum Cortisol as it regulates the expression of genes involved in BP. This is reinforced by Kirsch Baum et al. in his study which showed that Cortisol response to human CRH and mental stress can be significantly increased by hereditary factors.
| Conclusion|| |
Assessment of the Cardioadrenal reactivity showed statistically significant change after mental arithmetic test, in between with and without exercise groups. Therefore, we conclude that acute exercise can reduce the adrenocortical reactivity to stress in the offsprings of hypertensive parents, hence could serve as a preventive tool for development of hypertension in future.
Fundings were under the supervision of the Department of Physiology, MAMC, Delhi with proper approval from the finance department. Subjects didn’t have to do any extra expenses.
I would like to express my gratitude to my Professors and mentors who guided me throughout this study. Also, this study would have been incomplete without the help of my fellow colleagues and parents. I would like to thank them all.
The manuscript has been read and approved by all the authors, that the requirements for authorship as stated earlier in this document have been met, and that each author believes that the manuscript represents honest work
Financial support and sponsorship
Conflicts of interest
There has been no conflict of interests whatsoever during this study.
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[Figure 1], [Figure 2], [Figure 3]
[Table 1], [Table 2], [Table 3]