Abnormal sympathetic functioning is linked to familial hypertension in nonathletic young males
Jayesh Dalpatbhai Solanki1, Ajay P Kapadiya2, Hemant B Mehta1, Chinmay J Shah1
1 Department of Physiology, Government Medical College, Bhavnagar, Gujarat, India
2 Government Medical College, Bhavnagar, Gujarat, India
|Date of Submission||30-Jul-2018|
|Date of Acceptance||24-Dec-2018|
|Date of Web Publication||24-Apr-2019|
Dr. Jayesh Dalpatbhai Solanki
F1, Shivganga Appartments, Plot No 164, Bhayani Ni Waadi, Opp., Bawaliya Hanuman Temple, Gadhechi Wadlaa Road, Bhavnagar - 364 001, Gujarat
Source of Support: None, Conflict of Interest: None
BACKGROUND: Sympathetic overactivity mediates abnormal cardiovascular outcome that is affected by stress, lack of physical activity (PA), and familial hypertension (HTN). It can be assessed by blood pressure-based sympathetic function tests.
OBJECTIVE: We studied sympathetic function tests in young nonathletic males in relation to measures of obesity, PA, and familial HTN.
METHODOLOGY: We recruited 100 males (mean age: 19 years) and measured body mass index (BMI) and body composition parameters by tetrapolar bioelectrical impedance such as total body fat, visceral fat, subcutaneous fat, and skeletal muscle mass. Using instrument cardiac autonomic neuropathy system of Recorders and Medicare System Company, India, blood pressures (supine, standing, and post hand grip) were recorded and studied quantitatively and qualitatively.
RESULTS: Physically active and inactive individuals (n = 50 each) had comparable age, BMI, measures of obesity, and sympathetic function tests. However, individuals with familial HTN (n = 37) showed significantly higher obesity measures and blood pressures (supine: systolic blood pressure [SBP] – 133 vs. 115 and diastolic blood pressure [DBP] – 79 vs. 76; standing: SBP – 136 vs. 122 and DBP – 80 vs. 76; post hand grip: SBP – 136 vs. 125 and DBP – 86 vs. 81). Qualitatively, postural hypotension was seen in only two individuals, while worst grading was in post hand grip test significantly and more so in physically inactive group (30%, 28%, and 42% vs. 16%, 20%, and 64%) and individuals with positive familial HTN (32%, 38%, and 30% vs. 17%, 13%, and 70%).
CONCLUSION: Familial HTN, but not physical inactivity, affects sympathetic functioning in nonathletic young male medical personnel. It asks for other lifestyle modifications for better cardiovascular health as primary prevention.
Keywords: Blood pressure, family history, hypertension, physical activity, sympathetic
|How to cite this article:|
Solanki JD, Kapadiya AP, Mehta HB, Shah CJ. Abnormal sympathetic functioning is linked to familial hypertension in nonathletic young males. J Edu Health Promot 2019;8:88
|How to cite this URL:|
Solanki JD, Kapadiya AP, Mehta HB, Shah CJ. Abnormal sympathetic functioning is linked to familial hypertension in nonathletic young males. J Edu Health Promot [serial online] 2019 [cited 2019 Nov 18];8:88. Available from: http://www.jehp.net/text.asp?2019/8/1/88/257007
| Introduction|| |
With decline in communicable diseases, global focus is now shifted to noncommunicable diseases which are aftermaths of civilized culture. Our cardiovascular system is governed by autonomic nervous system, and sympathetic overdrive is known to be a cardiac risk factor. Stress, physical inactivity, and family history of hypertension (HTN) can increase sympathetic tone, which can be judged by simple sympathetic function tests. Measurement of heart rate and blood pressures is a simple parameter wherein former is the index of parasympathetic tone and latter is the index of sympathetic tone. These simple measures can easily reveal the picture that can give proof linking beneficial effect of physical activity (PA) on cardiovascular health as indicated by autonomic balance. Hence, we compared blood pressure-based sympathetic function tests between physically active and sedentary 18–35 years aged individuals.
| Methodology|| |
Study type and subjects
We conducted a cross-sectional study in clinical research laboratory of the physiology department of our medical college. Prior approval was taken from the institutional review board of our college and permission was taken from the physiology department of our college. Written informed consent was taken from participants undergoing study, and they were informed about benefit, objectivity, and aim of this study. Case group had 50 young athletic males, enrolled from our institute, doing minimum 5 h of moderate exercise in a week. Control group had 50 young sedentary males, enrolled from our institution, not involved in active exercise and living sedentary lifestyle.
Inclusion and exclusion criteria
We included male participants with known status of familial HTN, ready for written informed consent, aged between 18 and 35 years, without any medical or drug history. All cases were doing at least 5 h of regular moderate exercise in a week and controls were not. We excluded participants who were trained athletic individuals, not giving written informed consent, not knowing familial HTN status, known to have cardiovascular disease (CVD), addict to substance abuse or taking any medications affecting autonomic nervous system, and using any other lifestyle interventions such as yoga and meditation.
Assessment of body composition
A digital, portable noninvasive instrument Omron Karada Scan (Body Composition Monitor, Model HBF-510, Omron Healthcare Singapore Pvt. Limited, China) working on the principle of tetrapolar bioelectrical impedance analysis (BIA) was used. After entering age, gender, and height taken by standiometer, instrument was calibrated and a participant was allowed to stand on the instrument. It passes electric current of 500 μA at frequency 5 kHz to scan the whole body to derive regional body composition. BIA displays body weight (kg), body mass index (BMI), total body fat (TBF) %, visceral fat (VF) %, subcutaneous fat (SF), and skeletal muscle mass (SkMM).
Sympathetic function tests
We used cardiac autonomic neuropathy (CAN) system instrument of Recorders and Medicare Systems Pvt. Ltd., India. It is a computer-based CAN analysis system with interpretation. It measures:
- Resting systolic blood pressure (SBP) and diastolic blood pressure (DBP): A participant is given 5-min rest and then SBP and DBP measurement is done in the right brachial artery by instrument only
- SBP and DBP fall in response to standing: After recording resting BP, a participant stands unaided and immediately next BP measurement is done
- Rise in DBP in response to isometric exercise handgrip test
- A participant generates a maximum handgrip with handgrip dynamometer. Thereafter, 30% of maximum value is sustained for a period of time or until exhaustion, 1 min. Moreover, at the end of exercise, post test BP measurement is done
- Grading of postural hypotension – Grades 0, 1, and 2 based on supine to standing blood pressure changes
- Grading of post hand grip test blood pressure changed – Grades 0, 1, and 2 based on blood pressure changes after as compared to before sustained hand grip isometric exercise.
The data were expressed as mean ± standard deviation for quantitative variables and as number (percentage) for categorical variables. All calculations were accomplished by GraphPad InStat 3 software (demo version free software of GraphPad Software, Inc., California, USA). Observed difference in mean distribution of quantitative variables was compared by Student's t-test or Mann–Whitney U-test. Categorical data were tested for significant difference in distribution between groups by Chi-square test. Any observed difference was considered statistically significant with P < 0.05.
| Results|| |
There were equal numbered physically active and inactive males and former group chose cricket, body building, cycling, walking, and other sports [Figure 1]. None of the participants was involved in competitive sports or taking training as athlete. These groups had comparable age (mean: 19 years), height, weight, BMI (mean: 21 kg/m2), and heart rate (mean: 79 vs. 81). Physically active individuals had slightly better body composition profile and blood pressure results of sympathetic function testing, but except TBF (17% vs. 20%), all were statistically insignificant. Subgroup with positive family history of HTN (FH+, n = 37) was comparable to subgroup with negative family history of HTN (FH−, n = 63) in age and heart rate. FH − group had significantly better obesity measures than FH + group (weight – 59 vs. 68 kg, BMI – 20 vs. 24 kg/m2, TBF – 17 vs. 21%, VF – 7 vs. 5%, SF – 12 vs. 15%, and SkMM – 36 vs. 34%). As compared to FH − group, FH + group had more adverse blood pressures (supine: SBP – 133 vs. 115 and DBP – 79 vs. 76; standing: SBP – 136 vs. 122 and DBP – 80 vs. 76; post hand grip: SBP – 136 vs. 125 and DBP – 86 vs. 81) and rate pressure product (105 vs. 93) [Table 1].
|Table 1: Baseline and clinical parameters (mean±standard deviation) of whole study group and subgroups stratified by physical activity or family history of hypertension|
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Qualitative analysis of grading for sympathetic function test was done during change in posture from supine to standing and following isometric hand grip (IHG) test. All but two participants were free from postural hypotension (Grade 0), and these two participants were physically inactive having positive family history of HTN. Post hand grip test revealed sympathetic dysfunction to be more in physically inactive than active individuals (Grade 0 – 30% vs. 16%, Grade 1 – 28% vs. 20%, and Grade 2 – 42% vs. 64%) and in FH + group than FH − group (Grade 0 – 17% vs. 32%, Grade 1 – 13% vs. 38%, and Grade 2 – 70% vs. 30%), and these were statistically significant differences [Table 2].
|Table 2: Qualitative comparison of sympathetic functioning-postural hypotension grading and posthandgrip test grading between subgroups|
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| Discussion|| |
Self-reported moderate PA proved insignificant for sympathetic functioning, as assessed by blood pressure-based tests, among medical professionals. Other studies, done mostly in general population, contradict to this and mostly, highlight lesser sympathetic tone in individuals with active than sedentary lifestyle.,, This contrast can be due to few facts. First, we included only male participants. Middle-aged males tend to have more sympathetic control of cardiovascular system than females who have more of a parasympathetic control. This gender bias is absent after 50 years. Second, mean age was 19 years which may deny assessment of effect of aging. Autonomic tone is better in young individuals, and hence, postural sympathetic response was normal in all but 2 out of 100 participants. Third, physically active participants were not trained athletes. It is only strenuous anaerobic variety of exercise which can turn vagal tone to sympathetic tone at rest and moderate exercise is not harmful in this regard. Even participants doing moderate exercise had near-normal sympathetic tone, and this is in line with recommended intensity for healthy heart. Severe high-intensity anaerobic exercises rather impose a risk responsible for sudden cardiac death as previously documented. Fourth, all participants were exposed to mental stress of medical profession which may overshadow the impact of PA or inactivity. Parameters of body composition were not significantly better with PA. It can be due to lack of lifestyle modification apart from irregular PA and stressful way of living. Diet, sleep, salt intake, and other variables can blunt the benefits of moderate PA in young individuals.
Positive family history of HTN imposed higher blood pressures (supine, standing, and post handgrip) and higher rate pressure products despite comparable heart rate. This sympathetic dysfunction is known and supported by other studies.,, Such difference at age <35 years also underscores onset of early cardiovascular aging in individuals with familial HTN. Aging induces changes of reduced compliance and loss of elasticity of the aorta that increases impedance, and with early wave reflection, there is an increased workload on the heart which, in our case, was evident as significantly higher RPP. Such functional and structural changes define vascular phenotype of HTN, and we highlighted the same. Individual with a known history of HTN in family should better adapt to healthy lifestyle as primary prevention for them. Cases with familial HTN had significantly worst measures of obesity with increased overall obesity as weight, BMI, visceral obesity as VF, and reduced SkMM. This also supports the linkage of obesity to sympathetic over activity in individuals with inheritance of HTN. It also highlights that simple measures of weight control by healthy life measures can be used more so when stress level is continuous like medical profession. Comparable heart rate (mean: 80) in all groups indicates that parasympathetic tone is not much affected at this age. High rate pressure product despite comparable heart rate in cases with familial HTN highlights the importance of blood pressure and sympathetic over activity at this young age that needs corrective attention.
We observed a significantly better profile of sympathetic responsiveness to IHG test with PA and in the absence of familial HTN. IHG exercise training might be a simple, effective, inexpensive, and nonpharmacological method in lowering blood pressure. Static exercises are not useful in assessing the cardiovascular status of an individual or in predicting cardiovascular events. Our physically active participants were doing mainly dynamic exercise that leads to better IHG profile suggesting comparatively reduced CVD risk in them. Regular exercise is known to inculcate better sympathetic adjustment to isometric conditions.
In a recent study based on pulse wave analysis by Mobil-O-Graph, we found that young first-degree relatives of diabetics had significantly higher arterial stiffness parameters indicating vascular progeria. Using the same instrument in our population, we found higher central hemodynamics in young aged first-degree relatives of hypertensives. In both these studies,, alike this study, positive family history of diabetes or HTN rather than PA was a significant factor. These results support our observation but with respect to other parameters of cardiovascular health.
Good habits are being consolidated during school and college life, but sedentary modern lifestyle denies inclusion of structured and measurable athletic activities which are beneficial for health. Picture becomes even worse among science stream people more so in medical students. Although sympathetic tone was not proved to be affected by the presence of moderate PA, we have other tools to study it further and there are other health benefits of exercise, which were not present only in one facet that we questioned. In medical professionals, level of perceived stress and predominance of type A personality are suggested as culprits and their contribution cannot be neglected among study participants who were exposed to it.
Our study was limited by small sample size, exclusion of females, narrow range of age, presence of confounding factors, exclusion of parasympathetic function tests, absence of vertical follow-up, and lack of quantification of PA.
| Conclusion|| |
Positive family history of HTN, but not physical inactivity, affects sympathetic functioning in non-athletic young male medical personnel. It clues to other lifestyle modifications for better cardiovascular health as primary prevention of its aftermath, HTN.
We are thankful to the physiology department of our government medical college for allowing us to conduct this study and the medical personnel for their participation. We kindly acknowledge the Indian Council of Medical Research for selecting, approving, and funding this project under short-term studentship program 2015 for undergraduate medical students.
Financial support and sponsorship
This study was financially supported by the Indian Council of Medical Research under short-term studentship program of undergraduate medical students for the year 2015.
Conflicts of interest
There are no conflicts of interest.
| References|| |
World Health Organization. Global Status Report on Noncommunicable Diseases 2010. Geneva, Switzerland: WHO Press; 2011.
Rahmouni K. Obesity, sympathetic overdrive, and hypertension: The leptin connection. Hypertension 2010;55:844-5.
Brotman DJ, Golden SH, Wittstein IS. The cardiovascular toll of stress. Lancet 2007;370:1089-100.
Ino-Oka E, Sekino H, Ohtaki Y, Inooka H. Effects of daily physical activity level on the degree of sympathetic tone. Intern Med 2009;48:19-24.
Goldstein IB, Shapiro D, Weiss RE. How family history and risk factors for hypertension relate to ambulatory blood pressure in healthy adults. J Hypertens 2008;26:276-83.
Zygmunt A, Stanczyk J. Methods of evaluation of autonomic nervous system function. Arch Med Sci 2010;6:11-8.
Kenney WL. Parasympathetic control of resting heart rate: Relationship to aerobic power. Med Sci Sports Exerc 1985;17:451-5.
Guyenet PG. The sympathetic control of blood pressure. Nat Rev Neurosci 2006;7:335-46.
Patil SG, Dhanakshirur G, Aithala MR, Das KK. Comparison of the effects of yoga and lifestyle modification on grade-I hypertension in elderly males: A preliminary study. Int J Clin Exp Physiol 2014;1:68-72. [Full text]
Anjana RM, Pradeepa R, Das AK, Deepa M, Bhansali A, Joshi SR, et al.
Physical activity and inactivity patterns in India – Results from the ICMR-INDIAB study (Phase-1) [ICMR-INDIAB-5]. Int J Behav Nutr Phys Act 2014;11:26.
Mueller PJ. Exercise training and sympathetic nervous system activity: Evidence for physical activity dependent neural plasticity. Clin Exp Pharmacol Physiol 2007;34:377-84.
Laitinen T, Hartikainen J, Vanninen E, Niskanen L, Geelen G, Länsimies E, et al.
Age and gender dependency of baroreflex sensitivity in healthy subjects. J Appl Physiol (1985) 1998;84:576-83.
Kuo TB, Lin T, Yang CC, Li CL, Chen CF, Chou P, et al.
Effect of aging on gender differences in neural control of heart rate. Am J Physiol 1999;277:H2233-9.
Iellamo F, Legramante JM, Pigozzi F, Spataro A, Norbiato G, Lucini D, et al.
Conversion from vagal to sympathetic predominance with strenuous training in high-performance world class athletes. Circulation 2002;105:2719-24.
Haskell WL, Lee IM, Pate RR, Powell KE, Blair SN, Franklin BA, et al.
Physical activity and public health: Updated recommendation for adults from the American College of Sports Medicine and the American Heart Association. Med Sci Sports Exerc 2007;39:1423-34.
Corrado D, Basso C, Pavei A, Michieli P, Schiavon M, Thiene G, et al.
Trends in sudden cardiovascular death in young competitive athletes after implementation of a preparticipation screening program. JAMA 2006;296:1593-601.
Dahlin M, Joneborg N, Runeson B. Stress and depression among medical students: A cross-sectional study. Med Educ 2005;39:594-604.
Ranasinghe P, Cooray DN, Jayawardena R, Katulanda P. The influence of family history of hypertension on disease prevalence and associated metabolic risk factors among Sri Lankan adults. BMC Public Health 2015;15:576.
Kyvelou SM, Vyssoulis GP, Karpanou EA, Adamopoulos DN, Deligeorgis AD, Cokkinos DV, et al.
Arterial stiffness in offspring of hypertensive parents: A pilot study. Int J Cardiol 2008;129:438-40.
Kyvelou SM, Vyssoulis GP, Karpanou EA, Adamopoulos DN, Gialernios TP, Spanos PG, et al.
Arterial hypertension parental burden affects arterial stiffness and wave reflection to the aorta in young offsprings. Int J Cardiol 2010;144:156-60.
McEniery CM, Yasmin, Hall IR, Qasem A, Wilkinson IB, Cockcroft JR, et al.
Normal vascular aging: Differential effects on wave reflection and aortic pulse wave velocity: The Anglo-Cardiff collaborative trial (ACCT). J Am Coll Cardiol 2005;46:1753-60.
Garg R, Malhotra V, Kumar A, Dhar U, Tripathi Y. Effect of isometric handgrip exercise training on resting blood pressure in normal healthy adults. J Clin Diagn Res 2014;8:BC08-10.
Bhandari B, Kumar L, Datta A, Sircar S. Effect of sub maximal dynamic and static exercises on QTc interval in healthy young men. J Clin Diagn Res 2015;9:CC01-4.
Chrysant SG. Current evidence on the hemodynamic and blood pressure effects of isometric exercise in normotensive and hypertensive persons. J Clin Hypertens (Greenwich) 2010;12:721-6.
Solanki JD, Mehta HB, Shah CJ. Pulse wave analyzed cardiovascular parameters in young first degree relatives of type 2 diabetics- a cross-sectional study. Indian Heart J 2018;70:341-5.
Solanki JD, Mehta HB, Shah CJ. Pulse wave analyzed cardiovascular parameters in young first degree relatives of hypertensives. J Res Med Sci 2018;23:72.
] [Full text]
Paffenbarger RS Jr., Wing AL, Hyde RT, Jung DL. Physical activity and incidence of hypertension in college alumni. Am J Epidemiol 1983;117:245-57.
[Table 1], [Table 2]