Research Article

Age-related differences of rate and in the age group of 45–55 years – A regression analysis P. E. Jai Rexlin, V. B. Preejitha*, M. P. Brundha

ABSTRACT

Aim: The aim of this study is to determine the heart rate (HR) and respiratory rate (RR) differences between the age group of 45–55 years and correlate it with the age. Introduction: HR is the number of contractions (beats) of the heart/min (bpm). It is usually equal or close to the pulse measured at any peripheral point. The normal resting adult human HR is 60–100 bpm. Tachycardia is a fast HR, defined as above 100 bpm at rest. Bradycardia is a slow HR, defined as below 60 bpm at rest. When the heart is not beating in a regular pattern, this is referred to as arrhythmia. The RR is the number of breaths/ min. The typical RR for a healthy adult at rest is 12–18 breaths/min. Abnormal RRs – , dyspnea, , , , bradypnea, , , Biot’s respiration, Cheyne–Stokes respiration, and Kussmaul . Materials and Methods: A sample size of 100 healthy individuals was considered for this study between the age group of 45 and 55 years were selected randomly. Their HR and RR were measured at rest manually and were statistically analyzed. Results and Discussion: According to the regression analysis, 52% of the RR has a correlation to age, whereas only 32% of the HR has a correlation to the age. Conclusion: From the graph, it is evident that as the age increases, HR and RR decreases. Moreover, RR is more relevant according to the regression analysis. KEY WORDS: Heart rate, Regression analysis, Respiratory rate

INTRODUCTION HR is the number of contractions (beats) of the heart/ min (bpm). It is usually equal or close to the pulse Heartbeat and respiration are two prominent measured at any peripheral point. The normal resting physiological functions that are both modulated by adult human HR is 60–100 bpm. Tachycardia is a fast the fluctuations of the autonomic nervous system. HR, defined as above 100 bpm at rest. Bradycardia Hence, they carry information which may be used to is a slow HR, defined as below 60 bpm at rest. When gain insight into the autonomic control of the heart of the heart is not beating in a regular pattern, this is the lung. Alterations of these modulations may appear referred to as arrhythmia. HR reflects the balance during aging or during the progress of a disease.[1] of sympathetic and parasympathetic activity and is As a part of the general clinical examination, four influenced by several modifiable and non-modifiable [6] vital signs are routinely recorded: Heart rate (HR), factors. respiratory rate (RR), blood pressure, and temperature. The balancing action of the sympathetic nervous To derive meaningful information for any patient, we system and parasympathetic nervous system branches must compare the vital signs recorded against a normal of the autonomic nervous system controls the HR. or reference range. Normal values for temperature are well-established,[2] and there is good evidence for Increased sympathetic nervous system or diminished normal values of blood pressure at various ages.[3-5] parasympathetic nervous system activity results in With regard to RR and HR, however, there is little cardioacceleration. Conversely, a low sympathetic evidence on which to base our normal values. nervous system or a high parasympathetic nervous system activity causes cardio-deceleration.[7] Access this article online The RR is the number of breaths/min. The typical Website: jprsolutions.info ISSN: 0975-7619 RR for a healthy adult at rest is 12–18 breaths/min.[8]

Department of Pathology, Saveetha Dental College, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai, Tamil Nadu, India

*Corresponding author: Dr. V. B. Preejitha, Department of Pathology, Saveetha Dental College, Saveetha Institute of Medical and Technical Sciences, Saveetha University, 162, Poonamalle High Road, Chennai - 600 077, Tamil Nadu, India. Phone: +91-6383842981. E-mail: [email protected]

Received on: 19-09-2019; Revised on: 15-10-2019; Accepted on: 26-11-2019

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Abnormal RRs – apnea, dyspnea, hyperpnea, tachypnea, RESULTS hypopnea, bradypnea, orthopnea, platypnea, Biot’s respiration, Cheyne–Stokes respiration, and .

In view of the lack of evidence behind the values that are commonly quoted, we undertook a study to investigate the differences in HR and RR in 45–55 years population.[9]

MATERIALS AND METHODS A sample size of 100 healthy individuals was considered between the age group of 45–55 years and was selected randomly.

The HR and RR were measured at rest manually. From the graph, it is evident that as the age increases HR decreases.

From the graph, as the age increases RR decreases.

HR was measured by counting the number of heartbeats And also through the regression analysis, it was found over a period of 60 s by firmly and gently pressing the that only 32% of the HR had a correlation to the age, first and second fingertips against the wrist. whereas 52% of the RR had a correlation to the age.

The RR was measured by counting the number of DISCUSSION breaths/min through counting how many times the chest rises. HR at rest varies widely, but a pattern of distribution seems to exist. Indeed, in recent large studies, there Moreover, then the values were collected and seems to be a continuous increase in risk with HR, statistically analyzed through the regression analysis. at least for values above 60 beats/min, with no evidence of a threshold.[10,11] The respiratory rate Regression analysis is a statistical method to examine is an early indicator of disease, yet many clinicians the relationship between two or more variables of underestimate its vital role and hospitals report a poor interest. In this study, the relationship between HR and level of respiratory rate recording.[12] RR against age was examined through the regression analysis. From the epidemiological data presented in the previous article, it seems desirable to maintain HR Inclusion Criteria in the normal rather than in the high range, and Only healthy individuals without any underlying specifically, to maintain resting HR substantially systemic diseases were included in this study. below the traditionally defined tachycardia, the threshold of 90 or 100 beats/min.[7] Exclusion Criteria Individuals with underlying systemic diseases were When considering a desirable or optimal HR for an excluded from the study to avoid any errors. individual patient, demographic and measurement

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Table 1: Mean values in correlation with the age. Moreover, RR is more Age Heart rate (bpm) Respiratory rate (bpm) relevant to age. (mean) (mean) 45–50 81 16 REFERENCES 51–55 75 15 1. Cysarz D, Zerm R, Bettermann H, Frühwirth M, Moser M, Kröz M. Comparison of respiratory rates derived from heart rate variability, ECG amplitude, and nasal/oral airflow. Ann factors also must be taken into account. The HR has Biomed Eng 2008;36:2085-94. been reported to decrease with age in the previous 2. Lowrey GH. Growth and Development of Children. St Louis: study,[13] this study also proves to be the same. In the Mosby; 1986. present study, HR decreased with the increase in age 3. Voors AW, Webber LS, Berenson GS. Resting heart rate and pressure-rate product of children in a total biracial community: and had 32% correlation with the age, according to the The Bogalusa heart study. Am J Epidemiol 1982;116:276-86. regression analysis. 4. de Swiet M, Fayers P, Shinebourne EA. Blood pressure in first 10 years of life: The Brompton study. BMJ 1992;304:23-6. Nevertheless, the data that have been presented in the 5. Dark P, Woodford M, Vail A, Mackway-Jones K, Yates D, previous study suggest that an improved understanding Lecky F. Systolic hypertension and the response to blunt trauma in infants and children. Resuscitation 2002;54:245-53. of the relationship between HR, its modification, and 6. Valentini M, Parati G. Variables influencing heart rate. Prog cardiovascular health is important and potentially Cardiovasc Dis 2009;52:11-9. beneficial. To realize this benefit, the awareness of 7. Fox K, Borer JS, Camm AJ, Danchin N, Ferrari R, Lopez the potential importance of knowing the HR must be Sendon JL, et al. Resting heart rate in cardiovascular disease. [7] J Am Coll Cardiol 2007;50:823-30. enhanced. 8. Kim EB, Susan MB, Scott B, Heddwen B. Ganong’s Review of Medical Physiology. 24th ed. New York: McGraw-Hill Of the four vital signs, RR, in particular, is often Education; 2012. p. 619. not recorded, even when the patient’s primary be an 9. Wallis LA, Healy M, Undy MB, Maconochie I. Age related important predictor of serious events such as cardiac reference ranges for respiration rate and heart rate from 4 to [14] 16 years. Arch Dis Child 2005;90:1117-21. arrest. 10. Jouven X, Empana JP, Schwartz PJ, Desnos M, Courbon D, Ducimetière P. Heart-rate profile during exercise as a predictor If the RR is below normal, it could indicate central of sudden death. N Engl J Med 2005;352:1951-8. nervous system dysfunction. If the RR is above normal, 11. Diaz A, Bourassa MG, Guertin MC, Tardif JC. Long-term it could indicate underlying condition. Some variation prognostic value of resting heart rate in patients with suspected [15] or proven coronary artery disease. Eur Heart J 2005;26:967-74. in RR occurs naturally as the age increases, and in 12. McBride J, Knight D, Piper J, Smith GB. Long-term effect of the present study, the RR decreases with increase in introducing an early warning score on respiratory rate charting age and has 52% correlation with the age. on general wards. Resuscitation 2005;65:41-4. 13. Palatini P, Benetos A, Julius S. Impact of increased heart The RR is a very important vital sign. One study found rate on clinical outcomes in hypertension: Implications for antihypertensive drug therapy. Drugs 2006;66:133-44. that an elevated RR was a better determinant of people 14. Cretikos MA, Bellomo R, Hillman K, Chen J, Finfer S, who were stable versus unstable than HR or blood Flabouris A. Respiratory rate: The neglected vital sign. Med J pressure [Table 1].[16] Aust 2008;188:657-9. 15. Lockett E. Normal Respiratory Rate: For Kids and Adults Healthline. San Francisco, California: Healthline Media; 2019. CONCLUSION 16. Lynne E. Normal Respiratory Rates in Adults and Children. Verywell Health; 2020. Available from: https:// From the above-mentioned graph, it was evident www.verywellhealth.com/what-is-a-normal-respiratory- that, as the age increases, HR and RR decreases. rate-2248932. According to the regression analysis, respiratory age is 52% in correlation, whereas HR is only 32% Source of support: Nil; Conflicts of interest: None Declared

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