Children and Adolescents Macrovascular Reactivity Level and Dynamics, But Not the Microvascular Response, is Associated with Body Mass Index and Arterial Stiffness Levels

Abstract

Childhood obesity associates not only reduced, but also slowed macrovascular reactivity. Microvascular response to transient ischemia is preserved in obese children. Macro and microvascular responses would be non-associated phenomena in childhood. During childhood, VR dynamics would depend on the arterial stiffness.

Maternal nutritional restriction during gestation impacts differently on offspring muscular and elastic arteries and is associated with increased carotid resistance and ventricular afterload in maturity

“…In this regard, it is noteworthy that our group has experience in evaluating ovine and human cardiovascular systems in-vivousing both, invasive and non-invasive approaches. [25][26][27]41,42 Third, sheep are practically non-exposed to modifiable cardiovascular risk factors (unlike other animals who consume pro-atherogenic diets), which could modify the association between nutritional interventions and cardiovascular parameters. Then, potential confusing factors that could explain our cardiovascular findings were reduced.…”

“…Beat-to-beat diameter waveforms were obtained using border detection algorithm. 25,26 Systolic, mean and end-diastolic diameters and arterial intima-media thickness (computed on the posterior wall at end-diastole) were quantified (Hemodyn-4M/Dinap, Argentina). Pulsate diameter was calculated as systolic diameter minus diastolic diameter.…”

“…Blood flow velocity waves were analyzed considering widely used Doppler-derived indexes: resistive Index, pulsatility index and systo-diastolic velocity ratio. 25,26,28 Local characteristic impedance and regional peripheral vascular resistances From pressure and flow signals, 27,29 characteristic impedance was quantified as the ratio between BP (dP/dt; mmHg/s) and blood flow (dF/dt; ml/s) changes observed early in the systolic phase (early ejection). Additionally, carotid and femoral pathways (regional) resistances were quantified as the ratio between mean BP and blood flow.…”

Age- and sex-related profiles for macro, macro/micro and microvascular reactivity indexes: Association between indexes and normative data from 2609 healthy subjects (3-85 years)

“…Vascular reactivity (VR) defined as blood vessels' capability to actively modify the diameter and resistance in response to a stimulus (e.g., blood flow changes) can be non-invasively assessed following post-ischemic vascular response to forearm occlusion [1][2][3][4][5]. Schematically, distal microvessels are stimulated during inflation of a pressure cuff.…”

“…The occlusion causes transient ischemia, which stimulates dilation of distal resistance microvessels [5]. The high flow velocity, perfusion and/or the reduced resistances observed after cuff deflation (during reactive hyperemia (RH)) are considered´microvascular reactivity indexes´ [2][3][4][5][6]. In turn, diameter changes in the conduit artery (brachial artery, BA) before (e.g., low flow-mediated constriction) and after (e.g., flow-mediated dilation (FMD)) cuff-deflation are considered macrovascular reactivity indexes [2].…”