Maturation of Cardiovagal Autonomic Function From Childhood to Young Adult Age

Abstract

Background-Cardiovagal autonomic control declines with age in adult subjects, which is related in part to increasing stiffness of the barosensory vessel wall. It is not known, however, whether autonomic function changes with age in children. Methods and Results-We studied 137 healthy subjects divided into 4 age groups: group 1, 7 to 14 years; group 2, 11 to 14 years; group 3, 15 to 18 years; and group 4, 19 to 22 years. Brachial artery pressure was measured by sphygmomanometry and continuous radial artery pressure and carotid artery pulse pressure (⌬P) by applanation tonometry. The R-R interval was derived from the ECG. Autonomic function was assessed by spontaneous sequence and frequency-domain indices, which indicate the extent of coupling between fluctuations in heart rate and systolic pressure. Carotid artery diastolic diameter (DD) and pulsatile distension (⌬D) were measured by echo wall tracking; carotid compliance coefficient (CC) was defined as ⌬D/⌬P and distensibility coefficient as 2⌬D/DD · ⌬P. , with no significant changes afterward. CC and DC were inversely proportional to age (rϭϪ0.49 and Ϫ0.62, respectively, PϽ0.001). The efficiency of neural integrative mechanisms, estimated as the ratio of spontaneous indices and CC, more than doubled from group 1 to group 3. Spontaneous indices were linearly related to measures of cardiac vagal activity. Conclusions-The increase in spontaneous indices from early childhood to adolescence, despite gradual stiffening of the carotid artery, may indicate improved cardiovagal autonomic function, which is most likely a result of maturation of neural mechanisms, attaining peak level at adolescence.

Short-Term Heart Rate Variability in a Population-Based Sample of 10-Year-Old Children

“…These results are similar to previous research and support the notion that the timing of pubertal development coincides with the emergence and maturation of neural autonomic mechanisms [5,6,19,29]. Similar to the limited pediatric data of other studies, shorter sleep duration was associated with reduced HRV [24,32].…”

“…When all covariates were included in the models simultaneously, heart rate (β avg = −0. [19,48]. No comparisons could be made for SDANN and SDNNi, as they are infrequently reported in studies.…”

“…Further, important developmental factors are often not considered. Limited findings suggest younger age [19,37], pubertal status [5], greater physical activity [5,26], and consolidated sleep [18,19] are associated with a predominance of parasympathetic activity and reduced sympathetic modulation; yet, these have not been considered when deriving normative values. Collectively, these limitations hinder and bias interpretation and their practical applicability among clinicians.…”

Impaired short-term blood pressure regulation and autonomic dysbalance in children with type 1 diabetes mellitus

“…A negative correlation of BRS with systolic BP was also found (r=−0.23, p=0.009 in the entire patient group; r=−0.25, p=0.02 in the normotensive subgroup; r=−0.35, p=0.005 in the hypertensive subgroup). Comparing the BRS of our study population with normative data, 111 patients (74%) and five control patients (8.6%) showed a BRS SDS of <2 [20]. We explored the effects of disease-related factors, such as age at onset, height and weight, disease duration, daily insulin dose, HbA 1c concentration and total and LDL-cholesterol concentrations, by carrying out a multiple regression analysis.…”

“…Thus, impaired BRS may identify an at-risk group of diabetic children and adolescents at an early stage. During childhood, consecutive maturation of the autonomic nervous system has been shown [20]. The baroreflex function improves gradually until the age of 16 years in healthy adolescents.…”