Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Original Articles Acta Cardiol Sin 2008;24:35-8 Pediatric Cardiology Reference Values of Brachial-Ankle Pulse Wave Velocity in Children Chin-Fu Wang,1 Yu-Tsun Su1 and Kai-Sheng Hsieh2 Background: Arterial wall properties are important parameters reflecting the physical characteristics of the arteries. They bear relationship to cardiac-arterial interactions of the various arterial wall properties. Values of pulse wave velocity (PWV), especially the brachial-ankle PWV (baPWV) are a practical predictor of the severity of atherosclerosis in adults. However, changes of value of baPWV in healthy children (8-19 years old) have rarely been assessed. We therefore investigated the changes in values of baPWV in healthy Taiwanese children. Method: Between Oct. 2004 and Dec. 2005, in the Pediatric Cardiovascular Outpatient Department of Kaohsiung Veterans General Hospital, we measured values of baPWV and other vital measurements in 123 healthy (systolic blood pressure (SBP) 120 mmHg, body mass index (BMI) 24 and no underlying heart disease) children (51 boys and 72 girls). The relationship between baPWV and vital measurements was analyzed by linear regression and step-wise multiple linear regression using SPSS 10.0 software. Result: The value of baPWV could be predicted by ankle diastolic pressure (aDBP) and body height (Ht) (baPWV = 279.78 + 5.02 * aDBP + 2.67 * Ht, p < 0.05). It also increased with age, body weight (Wt), brachial systolic blood pressure (bSBP), and brachial diastolic blood pressure (bDBP), independently. It was not statistically correlated with BMI, heart rate (HR) or ankle systolic blood pressure (aSBP). Conclusion: Based on our results, it is worthwhile to use values of baPWV as indicators of changes in arterial wall properties in healthy Taiwanese children. Key Words: Pulse wave velocity · Blood pressure · Body mass index tion.1 It is believed that the value of baPWV increases with age and is a practical predictor of the severity of atherosclerosis in adults. Although atherosclerosis is rare in childhood, it is important to emphasize the ability of reference values of baPWV to reflect changes in arterial walls in children. In the past, there have been few studies 2-5 of developing children in other countries, or of adults in Taiwan. 6 Therefore, we investigated values of baPWV and analyze correlations between baPWV and vital measurements in healthy Taiwanese children. INTRODUCTION Arterial wall properties are important parameters reflecting the physical characteristics of the arteries. They bear relationship to cardiac-arterial interactions of the various arterial wall properties. Measuring the value of baPWV is recognized as a simple and non-invasive method of screening for arterial stiffness in a large popula- Received: May 8, 2007 Accepted: December 24, 2007 1 Department of Pediatrics, E-Da Hospital/I-Shou University; 2 Department of Pediatrics, Veterans General Hospital, Kaohsiung, Taiwan. Address correspondence and reprint requests to: Dr. Kai-Sheng Hsieh, Department of Pediatrics, Veterans General Hospital, No. 386, Ta-Chung 1st Rd, Kaohsiung 81364, Taiwan. Tel: 886-7-342-2121 ext. 8202; E-mail: [email protected] METHODS Between Oct. 2004 and Dec. 2005, we routinely measured values of baPWV, blood pressures of four 35 Acta Cardiol Sin 2008;24:35-8 Chin-Fu Wang et al. both prepubescent and postpubescent females were lower than those in the corresponding male groups (Table 3). In order to clarify the interactions among baPWV, age and gender, two-way ANOVA was performed. The results are shown in Table 4. The linear regression analysis of the values of baPWV and each correlated factor is shown in Figure 1. According to the results of step-wise multiple linear limbs, heart rate, body height, and body weight in 123 healthy children (8-19 years old, 51 boys and 72 girls) in the Pediatric Cardiovascular Outpatient Department of Kaohsiung Veterans General Hospital. Patients were examined in supine position, and sphygmomanometer cuffs were wrapped on the brachia and ankles. The cuffs inflated and deflated automatically, and pulse wave contours from the four extremities were recorded simultaneously. Pulse transit time between the brachial and ankle regions was computed from the pulse volume recording. Brachial-ankle PWV was determined from the pulse transit time and the distance between these two segments. The distance of each segment was calculated automatically, based on the height of the subject. 5 All measurements were taken by the same technician using the volume plethysmographic machine, Colin VP-1000 (Made in Japan).7 The inclusion criteria for subjects in our study were (1) normal age-related SBP ( 120 mmHg), (2) normal age-related BMI ( 24), (3) absence of underlying cardiovascular disease, and (4) absence of lipid disorder as reported by the family. The reference values of age-related SBP and BMI were published by the Department of Heath in Taiwan, 2002. Values of baPWV and blood pressures of the right arm and ankle were included in the analysis. We divided the subjects into groups on the basis of gender and pubescent stage. The values of baPWV, age, Ht, Wt, blood pressure, HR and BMI were analyzed by linear regression and step-wise multiple linear regression, using SPSS 10.0 software. Table 1. Characteristics of subjects n = 123 Age (years) Wt (kg) Ht (cm) BMI (kg/m2) HR (bpm) rbaPWV (cm/s) lbaPWV (cm/s) rbSBP (mmHg) rbDBP (mmHg) lbSBP (mmHg) lbDBP (mmHg) raSBP (mmHg) raDBP (mmHg) laSBP (mmHg) laDBP (mmHg) Female (72) 12.1 ± 2.7 046.6 ± 11.7 154.5 ± 15.1 19.2 ± 2.3 072 ± 11 1011 ± 159 0996 ± 142 108 ± 90 57 ± 5 109 ± 90 58 ± 6 125 ± 21 61 ± 8 121 ± 17 62 ± 8 12.7 ± 3.0 42.4 ± 8.3 150.6 ± 10.8 18.6 ± 2.3 071 ± 11 0979 ± 159 0959 ± 153 105 ± 90 57 ± 7 105 ± 90 57 ± 6 114 ± 15 61 ± 9 112 ± 13 60 ± 8 P < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 Wt: weight; Ht: height; BMI: body mass index; HR: heart rate; rbaPWV: right brachial-ankle pulse wave velocity; lbaPWV: left brachial-ankle pulse wave velocity; rbSBP: right brachial systolic blood pressure; rbDBP: right brachial diastolic blood pressure; lbSBP: left brachial systolic blood pressure; lbDBP: right brachial diastolic blood pressure; raSBP: right ankle systolic blood pressure; raDBP: right ankle diastolic blood pressure; laSBP: left ankle systolic blood pressure; laDBP: left ankle diastolic blood pressure. RESULTS Table 2. Pearson’s correlations of rbaPWV with each factor On the basis of gender, the characteristics of the two groups are summarized in Table 1. Systolic blood pressure and body weight were higher in the male group than in the female group. Although there was no statistically significant difference between baPWV in the two groups, female subjects had smaller values of baPWV than males. Correlations between baPWV and each factor are shown in Table 2. In females, age, Ht, Wt, bSBP, bDBP, and aDBP correlated positively with baPWV. This was different from males. On the other hand, values of baPWV in groups of Acta Cardiol Sin 2008;24:35-8 Male (51) Age Wt Ht BMI HR rbSBP rbDBP raSBP raDBP Male (51) Female (72) All (123) 0.218 0.203 0.234 -0.0210.104 0.176 *0.310* 0.023 **0.419** *0.352** 0.276* 0.283* 0.117* -0.037-* *0.331** 0.300* 0.208* 0.248* 0.287** 0.251** 0.266** 0.073** 0.021** 0.281** 0.300** 0.138** 0.316** *P < 0.05; **P < 0.01 36 Brachial-Ankle Pulse Wave Velocity in Children Table 3. rbaPWV (Mean ± SD, cm/s) of subjects divided on the basis of pubescent stage Male Prepuberty (8~11 y/o) Postpuberty (12~19 y/o) n = 22 960 ± 179 n = 29 1050 ± 1320 Female Table 4. Two-way ANOVA of rbaPWV for age and gender Variable P Sex Age Sex * Age n = 27 > 0.05 929 ± 129 n = 45 > 0.05 1009 ± 1680 F P 1.015 1.909 1.465 < 0.05 Figure 1. Relationships between rbaPWV and vital measurements (95% confidence interval). regression analysis with a 95% confidence interval, the value of baPWV was dependent on both aDBP and Ht (baPWV = 279.78 + 5.02 * aDBP + 2.67 * Ht, p < 0.05). male hormones affect the changes of arterial stiffening. However, in our study, prepubescent females had smaller values of baPWV than males (Table 3). We consider that precocious puberty may result those differences from other reports.5,8,9 On the other hand, age was positively correlated with baPWV in all subjects and females but not in males. We found the interaction of age and gender did not statistically affect the values of baPWV (Table 4). This result was also different from that in other reports. Nevertheless, the females had lower values of baPWV than the males. The structures of vessels change when an increase in DISCUSSIONS According to previous studies in children5 and adults, females have lower values of baPWV than males. Other studies8-10 reported that values of baPWV in prepubescent females were higher than those in males and then became lower after puberty. It was believed that fe8,9 37 Acta Cardiol Sin 2008;24:35-8 Chin-Fu Wang et al. 2. Avolio AP, Chen SG, Wang RP, et al. Effects of aging on changing arterial compliance and left ventricular load in a northern Chinese urban community. Circulation 1983;68:50-8. 3. Cheung YF, Brogan PA, Pilla CB, et al. Arterial distensibility in children and teenagers: normal evolution and the effect of childhood vasculitis. Arch Dis Child 2002;87:348-51. 4. Senzaki H, Akagi M, Hishi T, et al. Age-associated changes in arterial elastic properties in children. Eur J Pediatr 2002;161: 547-51. 5. Niboshi A, Hamaoka K, Sakata K, et al. Characteristics of brachial-ankle pulse wave velocity in Japanese children. Eur J Pediatr 2006;165(9):625-9. 6. Chuang SY, Chen CH, Cheng CM, Chou P. Combined use of brachial-ankle pulse wave velocity and ankle-brachial index for fast assessment of arteriosclerosis and atherosclerosis in a community. Int J Cardiol 2005;98(1):99-105. 7. Munakata M, Ito N, Nunokawa T, et al. Utility of automated brachial ankle pulse wave velocity measurements in hypertensive patients. Am J Hypertens 2003;16:653-7. 8. London GM, Gurein AP, Pannier B, et al. Influence of sex on arterial hemodynamics and blood pressure: role of body height. Hypertension 1995;37:1374-80. 9. Tomiyama H, Yamashina A, Arai T, et al. Influences of age and gender on results of noninvasive brachial-ankle pulse wave velocity measurement: a survey of 12517 subjects. Atherosclerosis 2003;30:303-9. 10. Ahimastos AA, Formosa M, Dart AM, et al. Gender differences in large artery stiffness pre- and postpuberty. J Clin Endocrinol Metab 2003;88:5375-80. 11. Yang L, Gao YJ, Lee RM. Quinapril effects on resistance artery structure and function in hypertension. Naunyn Schmiedebergs Arch Pharmacol 2004;370:444-51. 12. Athanase B, Chris A, Jeanne MB, et al. Determinants of accelerated progression of arterial stiffness in normotensive subjects and in treated hypertensive subjects over a 6-year period. Circulation 2002;105:1202-7. 13. Boutouyrie P, Tropeano AI, Asmar R, et al. Aortic stiffness is an independent predictor of primary coronary events in hypertensive patients: a longitudinal study. Hypertension 2002;39:10-5. 14. Shiotani A, Motoyama M, Matsuda T, et al. Brachial-ankle pulse wave velocity in Japanese university students. Intern Med 2005; 44(7):696-701. 15. Nakamura U, Iwase M, Nohara S, et al. Usefulness of brachialankle pulse wave velocity measurement: correlation with abdominal aortic calcification. Hypertens Res 2003;26:163-7. 16. Okamura T, Moriyama Y, Kadowaki T, et al. Noninvasive measurement of brachial-ankle pulse wave velocity is associated with serum C-reactive protein but not with alpha-tocopherol in Japanese middle-aged male workers. Hypertens Res 2004; 27:173-80. 17. Giral P, Atger V, Amar J, et al. A relationship between aortic stiffness and serum HDL3 cholesterol concentrations in hypercholesterolaemic, symptom-free men. J Cardiovasc Risk 1994;1: 53-8. blood pressure causes an augmentation of vascular tension.11-13 Increased cardiac output associated with age also strongly affects increases in blood pressure, and age-related increases in values of baPWV. In our study, blood pressure correlated positively with baPWV but heart rate did not. These results imply that heart rate can not statistically represent cardiac output, although cardiac output is the product of heart rate and stroke volume (CO = HR ´ SV). Unfortunately, we did not measure the stroke volume or ejection fraction in children by echocardiography. The values of cardiac output were not available. The value of BMI is usually considered to be a predictor of obesity, but it is not proportional to serum lipid levels. Therefore, higher BMI values are not correlated with hyperlipidemia, which predisposes to atherosclerosis. Several previous studies14-17 reported that baPWV was positively correlated with serum lipid levels but not with BMI. Although BMI is proportional to body weight, these measurements have different influences on the values of baPWV. Our results show that body weight correlated positively with baPWV but BMI did not. In addition, we did not check the serum lipid levels in subjects, so the relationship between baPWV and serum lipid levels was not clear. Although no subjects suffered cardiovascular disease, higher values of baPWV were measured in many patients. According to their family’s description, no lipid disorder had previously been found. Therefore, in order to know the exact metabolic conditions in our subjects, examinations of lipid profiles should be considered. According to our results, it is worthwhile to use values of baPWV as indicators of changes in arterial walls in healthy Taiwanese children. The values provide information regarding the health of developing children. In Taiwan, baPWV in adults has been studied.6 The results were consistent with those in previous studies elsewhere. More studies are necessary to determine and elaborate on the clinical significance of values of baPWV in children’s development. REFERENCES 1. Yamashina A, Tomiyama H, Takeda K, et al. Validity, reproducibility, and clinical significance of noninvasive brachial-ankle wave velocity measurement. Hypertens Res 2002;25:359-64. Acta Cardiol Sin 2008;24:35-8 38