Stefan and Irina: Factors Influencing Heart Rate Variability.

Introduction

The measurement and analysis of heart rate variability (HRV), which is based on the variation between consecutive NN intervals, has become an established procedure over the past two decades1-4 since the publication of the first guidelines5. Not only have there been advances in recording technology (smaller, more mobile, more accurate devices)6, but NN intervals can now also be measured by small chest strap and pulse watch systems7,8. Technological developments have decreased the costs of recording and analysis and have facilitated outpatient applications.

The variability of the successive differences between the NN intervals depends on sympathetic and parasympathetic influences. Mathematical algorithms can be used to calculate various HRV parameters from a time series of successive NN intervals. It is customary to make a distinction between so-called HRV parameters of the time domain and frequency domain and so-called non-linear HRV parameters5,7,9.

A decrease in HRV has been shown to correlate with an increase in mortality, for example after myocardial infarcts10-12, after bypass operations13, or in connection with cardiac insufficiency14.

HRV is influenced by a number of physiological factors such as various diseases. Awareness of these mediators or confounders is of great importance in the analysis and assessment of HRV both in scientific studies and in clinical practice.

Methods

This document, which is based on a selective survey of references and supplemented by information from national and international guidelines5,7, presents the main endogenous, exogenous, and constitutional factors. The references primarily cover metaanalyses and systematic reference surveys on the subject and is supplemented by extensive cohort studies.

Results

In addition to non-influenceable physiological parameters, a number of factors emanate from the lifestyle habits of the test persons, from the consequences of these habits and from external circumstances. A host of diseases go hand in hand with a decrease in HRV, while the influence on the vegetative nervous system can be regarded more as a result of diseases and only rarely as the potential cause of this decrease.

Physiological factors

Non-influenceable physiological factors include age, gender and circadian rhythm. A person’s HRV first increases sharply until they reach the age of one and continues to increase considerably until they reach the age of 15, while the resting heart rate decreases15. Their HRV then decreases as they grow older16-18. It also seems clear that there is a difference between men and women in the way the autonomous nervous system is regulated and thus in the sympathetic-parasympathetic balance, and this manifests itself in differing HRVs16,19-26. This difference between the genders seems to become less prominent when people reach the age of 50, a fact that is attributed to the postmenopausal hormonal changes that take place in women27,28. HRV, like a number of other physiological parameters, is subject not only to age and gender, but also to a circadian rhythm29. This must be taken into account in particular with short-term measurements ranging from a few minutes to a few hours are made. HRV increases at night and decreases considerably during the morning hours.

Genetics

While a genetic disposition of the HRV is discussed in twin studies30, Riese et al.31 did not establish any connection between eight key genes for the presence of acetylcholine receptors as part of the autonomous nervous system and the HRV level in an analysis of several cohort studies involving a total of 6,470 test persons.

In contrast, ethnic origin seems to have an influence on HRV. In a metaanalysis based on a systematic reference survey involving 17 studies and a total of 11,162 test persons, Hill et al.32 established a significantly higher short-term resting HRV in Afro-American test persons than in American test persons of European origin.

Diseases

The effects of various diseases on HRV have been examined in many studies. HRV is lower throughout among patients with the diseases concerned than among healthy test persons.

Sepsis

There is evidence that HRV decreases among people with severe acute diseases, including multiple organ failure, and that this decrease correlates with an increase in mortality33,34.

Heart diseases

A decrease in NRV has been found among people with heart disease and cardiac insufficiency35 or who have suffered a heart attack1. It has been known since the mid-1980s and was confirmed in a meta-analysis that a decrease in HRV correlates with an increase in mortality10. Also Hypertension reduced HRV36.

Lung diseases

People with a chronic obstructive pulmonary disease (COPD) also seem to have lower HRV37 and the degree to which the HRV is lower correlates with the severity of the COPD.

Renal diseases

HRV is also shown to be lower in patients with chronic kidney insufficiency than in healthy controls38.

Psychiatric diseases

People suffering from a series of psychiatric symptoms such as anxiety disorder39, panic attacks39,40, posttraumatic stress disorders41, epilepsy42, anorexia43, borderline personality disorder44 and depressions39,45,46 have been found to have lower HRV parameters.

It is in discussion if the reduction of HRV in patient with depression is caused by the depression itself or by the medication. O’Regan et al. have shown in a study with 4,750 peoples from Ireland that the medications lead to be the factor that reduced the HRV.47 On the other hand Yeh et al. have detected, that the depression itself reduced the HRV and not the medication. They compared 618 patients with a major depression with 506 healthy peoples48.

Metabolic diseases

HRV is also shown to be lower among people with metabolic diseases such as diabetes mellitus2,4. With respect to the metabolic syndrome, however, only women have been found to have lower HRV, and not men49.

Other diseases

While HRV studies concern a wide range of other diseases, there are at present only isolated studies on a major share of these diseases and most of them cover small groups of patients. A systematic review has revealed that only headaches50 correlated with a decrease in HRV.

Diseases with no influence on HRV

Systematic reviews have revealed that some diseases, e.g. rheumatoid arthritis, cause no clear changes in the HRV of those suffering from them51.

Lifestyle habits

In addition to these non-influenceable physiological factors, there are further factors, notably those related to the lifestyle habits of the test persons. These can have both a positive and a negative influence on HRV. They include physical fitness or sporting activity, increased body weight, which is sometimes negatively associated with the first two factors, active and passive smoking and regular alcohol abuse. People who have an active lifestyle and maintain a good or high level of physical fitness or above-average sporting activity can achieve an increase in their basic parasympathetic activity and thus an increase in their HRV52-56. Cumulative or too intensive sporting activity (e.g. competition series, overtraining syndrome), however, brings about a decrease in HRV52,54. In contrast, an elevated body weight or elevated free-fat mass57 correlates with a decrease in HRV. Both active and passive smoking lead to an increase in HRV58. Regular chronic alcohol abuse above the alcohol quantity of a standard drink for women or two standard drinks for men reduces HRV, while moderate alcohol consumption up to these quantities does not change the HRV and is not associated with an increase59.

External factors

In addition to climatic conditions and job-related parameters, several harmful substances and medications also have a direct or indirect influence on HRV. Climatic factors lead to changes in HRV due to the physiological reaction of the vegetative nervous system. Heat increases sympathetic nervous system activity, reducing HRV60,61. Long-term exposure to cold (e.g. at work or during the winter months) has not been found to have an influence on HRV60,62,63 due to adaptation effects, e.g. after 60 days. Exposure to noise likewise leads to a decrease in HRV because it increases sympathetic nervous system activity64-66. Induced pain also results in a lowering of HRV due to the activation of the physiological sympathetic nervous system67.

Night shift work over many years results in lower HRV due to the chronodisruption68-70. There seems to be a connection here between the length of time a person has done such shift work and the degree of the decrease in HRV.

Fig 1.

The different factors influencing HRV grouped into four main areas, * = HRV decrease as a result of a physiological reaction to a physical stimulus. Provides a summary of the results referring to the factors and covers the four main areas, i.e. non-influenceable physiological factors, illnesses, influenceable lifestyle factors, and external factors.

icfj.2016.6.18-g001.jpg

Some harmful substances (including acute diesel inhalation71, chronic exposure to lead72-73, cadmium74 and neurotoxic styrene75,76) and some medications (e.g. beta blockers, ACE inhibitors, antiarrhythmics and psychotropic drugs5) have been found to have a direct or indirect influence on HRV. In contrast, a systematic review by Gribble et al.77 merely revealed indications that exposure to mercury brings about a reduction in HRV. With respect to the effects of very early exposure to mercury, only a 14-year follow-up study involving children from the Faroe Islands has established an association between reduced HRV among children of seven and fourteen years of age and the mercury content in the umbilical cord blood at their births only77,78.

Summary

A decrease in HRV has been observed not only in connection with non-influenceable physiological factors such as age, gender and ethnic origin, but also in conjunction with a large number of acute and chronic diseases. Numerous lifestyle factors have both a positive and a negative influence on HRV. There are also physical influences that affect HRV. These must on no account be disregarded. Although not all the factors on the list have yet been fully studied, awareness of the many factors is of crucial importance in the measurement of HRV (both under laboratory conditions and during medical practice), its analysis and its assessment.

Declarations of Interest

The authors declare no conflicts of interest

Acknowledgements

The authors agree to abide by the requirements of the “Statement of publishing ethics of the International Cardiovasular Forum Journal”79.

References

1. 

Huikuri HV Mäkikallio TH. Heart rate variability in ischemic heart disease. Auton Neurosci 2001; 90: 95–101

2. 

Karayannis G, Giamouzis G, Cokkinos DV, Skoularigis J, Triposkiadis F Diabetic cardiovascular autonomic neuropathy: clinical implications. Expert Rev Cardiovasc Ther 2012; 10: 747–765 10.1586/erc.12.53

3. 

Korpelainen JT, Sotaniemi KA, Huikuri HV, Myllylä VV Circadian rhythm of heart rate variability is reversibly abolished in ischemic stroke. Stroke 1997; 28: 2150–2154

4. 

Kuehl M, Stevens MJ Cardiovascular autonomic neuropathies as complications of diabetes mellitus. Nat Rev Endocrinol 2012; 8: 405–416 10.1038/nrendo.2012.21

5. 

European Society of Cardiology und North American Society of Pacing and Electrophysiology. Heart rate variability: standards of measurement, physiological interpretation and clinical use. Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology. Circulation 1996; 93: 1043–1065

6. 

Körber T, Ismer B, von Knorre GH Influences of Holter recording technology on time domain heart rate variability - laboratory investigations. Herzschr Elektrophys 2000; 11: 59–65

7. 

Sammito S, Thielmann B, Seibt R, Klussmann A, Weippert M, Böckelmann I Guideline for the application of heart rate and heart rate variability in occupational medicine and occupational science. ASU International Edition 2015; 10.17147/ASUI.2015-06-09-03

8. 

Wallén MB, Hasson D, Theorell T, Canlon B, Osika W Possibilities and limitations of the Polar RS800 in measuring heart rate variability at rest. Eur J Appl Physiol 2012; 112: 1153–1165 10.1007/s00421-011-2079

9. 

Sassi R, Cerutti S, Lombardi F, Malik M, Huikuri HV, Peng CK, Schmidt G, Yamamoto Y, Gorenek B, Lip GY, Grassi G, Kudaiberdieva G, Fisher JP, Zabel M, Macfadyen R Advances in heart rate variability signal analysis: joint position statement by the e-Cardiology ESC Working Group and the European Heart Rhythm Association co-endorsed by the Asia Pacific Heart Rhythm Society. Europace 2015; 17: (9)1341–1353 10.1093/europace/euv015

10. 

Buccelletti E, Gilardi E, Scaini E, Galiuto L, Persiani R, Biondi A, Basile F, Silveri NG Heart rate variability and myocardial infarction: systematic literature review and metaanalysis. Eur Rev Med Pharmacol Sci 2009; 13(4)299–307 10.1002/14651858.CD006577.pub3

11. 

Huikuri HV, Stein PK Heart rate variability in risk stratification of cardiac patients. Prog Cardiovasc Dis 2013; 56: (2)153–159 10.1016/j.pcad.2013.07.003

12. 

Song T, Qu XF, Zhang YT, Cao W, Han BH, Li Y, Piao JY, Yin LL, Da Cheng H Usefulness of the heart-rate variability complex for predicting cardiac mortality after acute myocardial infarction. BMC Cardiovasc Disord 2014; 14: 59 10.1186/1471-2261-14-59

13. 

Lakusic N, Mahovic D, Sonicki Z, Slivnjak V, Baborski F Outcome of patients with normal and decreased heart rate variability after coronary artery bypass grafting surgery. Int J Cardiol 2013; 166: (2)516–518 10.1016/j.ijcard.2012.04.040

14. 

Sandercock GR, Brodie DA The role of heart rate variability in prognosis for different modes of death in chronic heart failure. Pacing Clin Electrophysiol 2006; 29: (8)892–904

15. 

Eyre ELJ, Duncan MJ, Birch SL, Fisher JP The influence of age and weight status on cardiac autonomic control in healthy children: a review. Auton Neurosci 2014; 186: 8–21 10.1016/j.autneu.2014.09.019

16. 

Abhishekh HA, Nisarga P, Kisan R, Meghana A, Chandran S, Trichur Raju, Sathyaprabha TN Influence of age and gender on autonomic regulation of heart. J Clin Monit Comput 2013; 27: (3)259–264 10.1007/s10877-012-9424-3

17. 

Shiogai Y, Stefanovska A, McClintock PV Nonlinear dynamics of cardiovascular ageing. Phys Rep 2010; 488: (2-3)51–110

18. 

Voss A, Schulz S, Schroeder R, Baumert M, Caminal P Methods derived from nonlinear dynamics for analysing heart rate variability. Phil Trans R Soc A 2009; 367: (1887)277–296 10.1098/rsta.2008.0232

19. 

Agelink MW, Malessa R, Baumann B, Majewski T, Akila F, Zeit T, Ziegler D Standardized tests of heart rate variability: normal ranges obtained from 309 healthy humans, and effects of age, gender, and heart rate. Clin Auton Res 2001; 11: (2)99–108

20. 

Barantke M, Krauss T, Ortak J, Lieb W, Reppel M, Burgdorf C, Pramstaller PP, Schunkert H, Bonnemeier H Effects of gender and aging on differential autonomic responses to orthostatic maneuvers. J Cardiovasc Electrophysiol 2008; 19(12)1296–303 10.1111/j.1540-8167.2008.01257.x

21. 

Jensen-Urstad K, Storck N, Bouvier F, Ericson M, Lindblad LE, Jensen-Urstad M Heart rate variability in healthy subjects is related to age and gender. Acta Physiol Scand 1997; 160: (3)235–241

22. 

Ramaekers D, Ector H, Demyttenaere K, Rubens A, Van de Werf F Association between cardiac autonomic function and coping style in healthy subjects. Pacing Clin Electrophysiol. 1998; 21: (8)1546–1552

23. 

Snieder H, van Doornen LJ, Boomsma DI, Thayer JF Sex differences and heritability of two indices of heart rate dynamics: a twin study. Twin Res Hum Genet 2007; 10: (2)364–372

24. 

Sookan T, McKune AJ Heart rate variability in physically active individuals: reliability and gender characteristics. Cardiovasc J Afr 2012; 23: (2)67–72 10.5830/CVJA-2011.108

25. 

Tsuji H, Venditti FJ Jr, Manders ES, Evans JC, Larson MG, Feldman CL, Levy D Determinants of heart rate variability. J Am Coll Cardiol 1996; 28: (6)1539–1546

26. 

Umetani K, Singer DH, McCraty R, Atkinson M Twenty-four hour time domain heart rate variability and heart rate: relations to age and gender over nine decades. J Am Coll Cardiol 1998; 31: (3)593–601

27. 

Fagard RH A population-based study on the determinants of heart rate and heart rate variability in the frequency domain. Verh K Acad Geneeskd Belg 2001; 63: (1)57–89

28. 

Huikuri HV, Pikkujamsa SM, Airaksinen KE, Ikäheimo MJ, Rantala AO, Kauma H, Lilja M, Kesäniemi YA Sex-related differences in autonomic modulation of heart rate in middle-aged subjects. Circulation 1996; 94: (2)122–125

29. 

Rodríguez-Colón S, He F, Bixler EO, Fernandez-Mendoza J, Vgontzas AN, Berg A, Kawasawa YI, Liao D The circadian pattern of cardiac autonomic modulation and obesity in adolescents. Clin Auton Res 2014; 24: 265–273 10.1007/s10286-014-0257-7

30. 

Riese H, Rosmalen JGM, Ormel J, van Roon AM, Oldehinkel AJ, Rijsdijk FV The genetic relationship between neuroticism and autonomic function in female twins. Psychol Med 2007; 37: (2)257–267

31. 

Riese H, Muñoz LM, Hartman CA, Ding X, Su S, Oldehinkel AJ, van Roon AM, van der Most PJ, Lefrandt J, Gansevoort RT, van der Harst P, Verweij N, Licht CM, Boomsma DI, Hottenga JJ, Willemsen G, Penninx BW, Nolte IM, de Geus EJ, Wang X, Snieder H Identifying genetic variants for heart rate variability in the acetylcholine pathway. PloS ONE 2014; 9: (11)e112476 10.1371/journal.pone.0112476

32. 

Hill LK, Hu DD, Koenig J, Sollers JJ, 3rdKapuku G, Wang X, Snieder H, Thayer JF Ethnic differences in resting heart rate variability: a systematic review and meta-analysis. Psychosom Med 2015; 77: (1)16–25 10.1097/PSY.0000000000000133

33. 

Schmidt H, Hoyer D, Hennen R, Heinroth K, Rauchhaus M, Prondzinsky R, Hottenrott K, Buerke M, Müller-Werdan U, Werdan K Autonomic dysfunction predicts both 1- and 2-month mortality in middle-aged patients with multiple organ dysfunction syndrome. Crit Care Med 2008; 36: (3)967–970 10.1097/CCM.0B013E3181653263

34. 

Schmidt H, Lotze U, Ghanem A, Anker SD, Said SM, Braun-Dullaeus R, Oltmanns G, Rose S, Buerke M, Müller-Werdan U, Werdan K, Rauchhaus M Relation of impaired interorgan communication and parasympathetic activity in chronic heart failure and multiple-organ dysfunction syndrome. J Crit Care 2014; 29: (3)367–373 10.1016/j.jcrc.2013.12.015

35. 

Guzzetti S, Magatelli R, Borroni E, Mezzetti S Heart rate variability in chronic heart failure. Auton Neurosci 2001; 90: (1-2)102–5

36. 

Carthy ER Autonomic dysfunction in essential hypertension: A systematic review. Ann Med Surg (Lond) 2013; 3: (1)2–7 10.1016/j.amsu.2013.11.002

37. 

Roque AL, Valenti VE, Massetti T, da Silva TD, Monteiro CB, Oliveira FR, de Almeida Junior ÁD, Lacerda SN, Pinasco GC, Nascimento VG, Granja Filho LG, de Abreu LC, Garner DM, Ferreira C Chronic obstructive pulmonary disease and heart rate variability: a literature update. Int Arch Med 2014; 7: 43 10.1186/1755-7682-7-43

38. 

Zhang J, Wang N Prognostic significance and therapeutic option of heart rate variability in chronic kidney disease. Int Urol Nephrol 2014; 46: 19–25 10.1007/s11255-013-0421-3

39. 

Birkhofer A, Schmidt G, Förstl H Heart and brain -- the influence of psychiatric disorders and their therapy on the heart rate variability. Fortschr Neurol Psychiat 2005; 73: (4)192–205

40. 

Friedmann BH, Thayer JF Autonomic balance revisited: panic anxiety and heart rate variability. J Psychosom Res 1998; 44: (1)133–51

41. 

Sammito S, Thielmann B, Zimmermann P, Böckelmann I Influence of post-traumatic stress disorder on heart rate variability as marker of the autonomic nervous system — a systematic review. Forts Neurol Psych 2015; 83: 30–37 10.1055/s-0034-1398779

42. 

Lotufo PA, Valiengo L, Benseñor IM, Brunoni AR A systematic review and meta-analysis of heart rate variability in epilepsy and antiepileptic drugs. Epilepsia 2012; 53: (2)272–282 10.1111/j.1528-1167.2011.03361.x

43. 

Chalmers JA, Quintana DS, Abbott MJA, Kemp AH Anxiety Disorders are associated with reduced heart rate variability: a meta-analysis. Front Psychiatry 2014; 5: 80 10.3389/fpsyt.2014.00080

44. 

Koenig J, Kemp AH, Feeling NR, Thayer JF, Kaess M Resting state vagal tone in borderline personality disorder: A meta-analysis. Prog Neuropsychopharmacol Biol Psychiatry 2016; 64: 18–26 10.1016/j.pnpbp.2015.07.002

45. 

Kapfhammer HP The relationship between depression, anxiety and heart disease - a psychosomatic challenge. Psychiatr Danub 2011; 23: (4)412–424

46. 

Stapelberg NJ, Hamilton-Craig I, Neumann DL, Shum DH, McConnell H Mind and heart: heart rate variability in major depressive disorder and coronary heart disease - a review and recommendations. Aust N Z J Psychiatry 2012; 46: (10)946–957 10.1177/0004867412444624

47. 

O’Regan C, Kenny RA, Cronin H, Finucane C, Kearney PM Antidepressants strongly influence the relationship between depression and heart rate variability: findings from The Irish Longitudinal Study on Ageing (TILDA). Psychol Med 2015; 45: (3)626–36 10.1017/S0033291714001767

48. 

Yeh TC, Kao LC, Tzeng NS, Kuo TB, Huang SY, Chang CC, Chang HA Heart rate variability in major depressive disorder and after antidepressant treatment with agomelatine and paroxetine: Findings from the Taiwan Study of Depression and Anxiety (TAISDA). Prog Neuropsychopharmacol Biol Psychiatry 2016; 64: 60–67 10.1016/j.pnpbp.2015.07.007

49. 

Stuckey MI, Tulppo MP, Kiviniemi AM, Petrella RJ Heart rate variability and the metabolic syndrome: a systematic review of the literature. Diabetes Metab Res Rev 2014; 30: (8)784–793 10.1002/dmrr.2555

50. 

Koenig J, Williams DWP, Kemp AH, Thayer JF Vagally mediated heart rate variability in headache patients - a systematic review and meta-analysis. Cephalgia 2015; pii: 0333102415583989

51. 

Adlan AM, Lip GYH, Paton JFR, Kitas GD, Fisher JP Autonomic function and rheumatoid arthritis: a systematic review. Semin Arthritis Rheum 2014; 44: (3)283–304 10.1016/j.semarthrit.2014.06.003

52. 

Aubert AE, Seps B, Beckers F Heart rate variability in athletes. Sports Med 2003; 33: 889–919

53. 

Bernardi L, Piepoli ME Autonomic nervous system adaption during physical exercise. Ital Heart J 2001; 2: 831–839

54. 

Hottenrott K, Hoos O, Esperer HD Heart rate variability and physical exercise. Current status. Herz 2006; 31: (6)544–552

55. 

Routledge FS, Campbell TS, McFetridge-Durdle JA, Bacon SL Improvements in heart rate variability with exercise therapy. Can J Cardiol 2010; 26: (6)303–312

56. 

Sandercock GRH, Bromley PD, Brodie DA Effects of exercise on heart rate variability: inferences from meta-analysis. Med Sci Sports Exerc 2005; 37: (3)433–439

57. 

Fraley MA, Birchem JA, Senkottaiyan N, Alpert MA Obesity and the electrocardiogram. Obes Rev 2005; 6: (4)275–81

58. 

Dinas PC, Koutedakis Y, Flouris AD Effects of active and passive tobacco cigarette smoking on heart rate variability. Int J Cardiol 2013; 163: (2)109–115 10.1016/j.ijcard.2011.10.140

59. 

Karpyak VM, Romanowicz M, Schmidt JE, Lewis KA, Bostwick JM Characteristics of heart rate variability in alcohol-dependent subjects and nondependent chronic alcohol users. Alcohol Clin Exp Res 2014; 38: (1)9–26 10.1111/acer.12270

60. 

Ren C, O’Neill MS, Park SK, Sparrow D, Vokonas P, Schwartz J Ambient temperature, air pollution, and heart rate variability in an aging population. Am J Epidemiol 2011; 173: (9)1013–1021 10.1093/aje/kwq477

61. 

Wu S, Deng F, Liu Y, Shima M, Niu J, Huang Q, Guo X Temperature, traffic related air pollution, and heart rate variability in a panel of healthy adults. Environ Res 2013; 120: 82–89 10.1016/j.envres.2012.08.008

62. 

Bortkiewicz A, Gadzicka E, Szymczak W, Szyjkowska A, Koszada Wł, odarczyk W, Makowiec-Dabrowska T Physiological reaction to work in cold microclimate. Int J Occup Med Environ Health 2006; 19: (2)123–131

63. 

Harinath K, Malhotra AS, Pal K, Prasad R, Kumar R, Sawhney RC Autonomic nervous system and adrenal response to cold in man at Antarctica. Wilderness Environ Med 2005; 16: (2)81–91

64. 

Kraus U, Schneider A, Breitner S, Hampel R, Rückerl R, Pitz M, Geruschkat U, Belcredi P, Radon K, Peters A Individual daytime noise exposure during routine activities and heart rate variability in adults: A repeated measures study. Environ Health Perspect 2013; 121: (5)607–612

65. 

Lee GS, Chen ML, Wang GY Evoked response of heart rate variability using short-duration white noise. Auton Neurosci 2010; 155: (1-2)94–97 10.1016/j.autneu.2009.12.008

66. 

Schnell I, Potchter O, Epstein Y, Yaakov Y, Hermesh H, Brenner S, Tirosh E The effects of exposure to environmental factors on heart rate variability: An ecological perspective. Environ Pollut 2013; 183: 7–13 10.1016/j.envpol.2013.02.005

67. 

Koenig J, Jarczok MN, Ellis RJ, Hillecke TK, Thayer JF Heart rate variability and experimentally induced pain in healthy adults: a systematic review. Eur J Pain 2014; 18: (3)301–314 10.1002/j.1532-2149.2013.00379.x

68. 

Ha M, Kim J, Park J, Chung HK Blood pressure and heart rate variability in workers of 8-hour shifts. J Hum Ergol (Tokyo) 2001; 30(1-2)229–33

69. 

Lindholm H, Sinisalo J, Ahlberg J, Hirvonen A, Hublin C, Partinen M, Savolainen A Attenuation of vagal recovery during sleep and reduction of cortisol/melatonin ratio in late afternoon associate with prolonged daytime sleepiness among media workers with irregular shift work. Am J Ind Med. 2012; 55: (7)643–649 10.1002/ajim.22042

70. 

Wehrens SM, Hampton SM, Skene DJ Heart rate variability and endothelial function after sleep deprivation and recovery sleep among male shift and non-shift workers. Scand J Work Environ Health 2012; 38: (2)171–181 10.5271/sjweh.3197

71. 

Brito JM, Belotti L, Toledo AC, Antonangelo L, Silva FS, Alvim DS, Andre PA, Saldiva PH, Rivero DH Acute cardiovascular and inflammatory toxicity induced by inhalation of diesel and biodiesel exhaust particles. Toxicol Sci. 2010; Jul116(1)67–78 10.1093/toxsci/kfq107

72. 

Böckelmann I, Pfister EA, McGauran N, Robra B-P Assessing the suitability of cross-sectional and longitudinal cardiac rhythm tests with regard to identifying effects of occupational chronic lead exposure. J Occup Environ Med 2002; 44: (1)59–65

73. 

Murata K, Araki S, Yokoyama K, Nomiyama K, Nomiyama H, Tao YX, Liu SJ Autonomic and central nervous system effects of lead in female glass workers in China. Am J Ind Med 1995; 28: (2)233–244

74. 

Feng W, He X, Chen M, Deng S, Qiu G, Li X, Liu C, Li J, Deng Q, Huang S, Wang T, Dai X, Yang B, Yuan J, He M, Zhang X, Chen W, Kan H, Wu T Urinary metals and heart rate variability: a cross-sectional study of urban adults in Wuhan, China. Environ Health Perspect 2015; 123: (3)217–22 10.1289/ehp.1307563

75. 

Murata K, Araki S, Yokoyama K, Maeda K Autonomic and peripheral nervous system dysfunction in workers exposed to mixed solvents. Int Arch Occup Environ Health 1991; 63: 335–340

76. 

Murata K, Araki S, Yokoyama K Assessment of the peripheral, central, and autonomic nervous system function in styrene workers. Am J Ind Med 1991; 20: 775–784

77. 

Gribble MO, Cheng A, Berger RD, Rosmann L, Guallar E Mercury exposure and heart rate variability: a systematic review. Curr Envir Health Rep 2015; 2: (3)304–14 10.1007/s40572-015-0053-0

78. 

Grandjean P, Murata K, Budtz-Jørgensen E, Weihe P Cardiac autonomic activity in methylmercury neurotoxicity: 14-year follow-up of a Faroese birth cohort. J Pediatr 2004; 144: (2)169–76

79. 

Shewan LG, Coats AJS, Henein M Requirements for ethical publishing in biomedical journals. International Cardiovascular Forum Journal 2015; 2: 2 10.17987/icfj.v2i1.4



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