Early Progression of the Autonomic Dysfunction Observed in Pediatric Type 1 Diabetes Mellitus

Abstract

Abstract-To focus on early cardiac and vascular autonomic dysfunction that might complicate type 1 diabetes mellitus in children, we planned an observational, cross-sectional study in a population of 93 young patients, under insulin treatment, subdivided in 2 age subgroups (children: 11.5Ϯ0.4 years; adolescents: 19.3Ϯ0.2 years). Time and frequency domain analysis of RR interval and systolic arterial pressure variability provided quantitative indices of the sympatho-vagal balance regulating the heart period, of the gain of cardiac baroreflex, and of the sympathetic vasomotor control. Sixty-eight children of comparable age served as a reference group. At rest, systolic arterial pressure and the power of its low-frequency component were greater in patients than in controls, particularly in children (14.0Ϯ2.3 versus 3.1Ϯ0.3 mm Hg 2 ). Moreover, baroreflex gain was significantly reduced in both subgroups of patients. Standing induced similar changes in the autonomic profiles of controls and patients. A repeat study after 1 year showed a progression in low-frequency oscillations of arterial pressure and a shift toward low frequency in RR variability. Data in young patients with type 1 diabetes mellitus show a significant increase in arterial pressure, a reduced gain of the baroreflex regulation of the heart period, and an increase of the low-frequency component of systolic arterial pressure variability, suggestive of simultaneous impairment of vagal cardiac control and increases of sympathetic vasomotor regulation. A repeat study after 1 year shows a further increase of sympathetic cardiac and vascular modulation, suggesting early progression of the autonomic dysfunction. Key Words: autonomic nervous system Ⅲ baroreflex Ⅲ children Ⅲ diabetes mellitus Ⅲ sympathetic nervous system Ⅲ vasculature C ardiovascular autonomic neuropathy is a severe, frequently underrecognized complication of diabetes mellitus, of which the presence approximately doubles the all-cause mortality risk. 1 Traditionally, clinical markers of diabetic cardiovascular autonomic neuropathy are based on a battery of tests 2 requiring the active collaboration of patients; however, new methods have been described to assess the integrity of autonomic function, such as spectral analysis of RR interval variability 3,4 or baroreflex sensitivity (BRS) 5,6 , that can be obtained automatically from computer analysis of noninvasive ECG and arterial pressure wave recordings, without needing the active participation of patients. These latter methods have been considered more sensitive 7 than traditional tests and, thus, could be particularly suited to assess initial changes in autonomic performance, particularly in young patients affected by type 1 diabetes mellitus (T1DM).In adults, available data suggest that, with time, cardiovascular autonomic neuropathy 8 becomes characterized by reduced vagal control of the sinoatrial node, as expressed by reduced RR variance and baroreflex gain, together with impaired vascular regulation, as exemplified by reduced orthostati...

Geometric indexes of heart rate of variability identifies autonomic alterations in young patients with type 1 diabetes mellitus

“…However, another study did not find similar results compared with the present one for LF ms² index (42), which can be due to exogenous insulin increasing sympathetic activity, displacing the balance to the LF component (42), or by the methodological limitations for evaluation this sympathetic activity, because the LF index do not demonstrate a pure activity of this ANS component (43).…”

Impaired diffusing capacity for carbon monoxide in children with type 1 diabetes: is this the first sign of long-term complications?

“…Blood has been drawn for HbA1c analyzed by a fully automated high-performance liquid-chromatographic system (Variant II, Bio-Rad Laboratories, Munich, Germany); moreover, levels of hemoglobin and lipids were evaluated in all subjects. Autonomic function and albumin excretion rate have been evaluated as previously reported [10,11]. In particular, autonomic function was assessed as follow: after a preliminary 10-min rest period in supine position, allowed for stabilization, blood pressure waveforms, ECG, and respiratory activity are continuously recorded over a 10-min baseline and over a subsequent 7-min period of active standing.…”

Blood pressure variability in relation to autonomic nervous system dysregulation: the X-CELLENT study

“…A more complicated methodology involving spectral analysis of the R-R interval and the SBP variability was employed by Lucini et al to investigate the impaired ANS regulation in hypertensive patients. 12,13 Compared with those parameters, our dSBP/dHR is the simplest index and is conveniently derived from 24-h ABPM, thereby rendering it more pragmatic for clinical practice.…”