Deep breathing acutely improves arterial dysfunction in obese children: Evidence of functional impairment?

Background and aims: Similarly to diabetes type 2, patients with obesity show insulin resistance and autonomic and vascular abnormalities associated with increased morbidity and mortality. We tested whether arterial dysfunction in obese children may have a functional nature, reversible with appropriate interventions (e.g., by reduction of sympathetic activity), or else results from anatomic arterial modifications (likely irreversible). For this purpose, we tested whether deep breathing (an intervention known to transiently reduce sympathetic activity) could acutely improve arterial function, hence showing a functional abnormality. Methods and results: A total of 130 obese children and 67 age-matched healthy normal-weight control children were recruited. Arterial function was measured by augmentation index (AIx), by direct analysis of blood pressure contour, and by pulse wave velocity (PWV), during spontaneous and controlled breathing. The markers of metabolic syndrome were evaluated at baseline. AIx showed increased values in obese male participants as compared with the control group. Slow breathing acutely reduced Aix in obese children, to a greater extent than in normal-weight control children. Similarly, the blood pressure contour showed higher values in obese children that were significantly attenuated by slow breathing. Baseline PWV was not altered in obese participants. The markers of metabolic syndrome correlated with AIx and PWV. Conclusions: Obese subjects showed impaired arterial function. The acute improvement in vascular abnormalities with reduction in sympathetic activity indicates that this alteration was largely functional, likely related to initial autonomic dysfunction and to metabolic abnormalities. As a consequence, this study provides a rationale for strategies aiming at preventing arterial function deterioration in the early ages. (C) 2014 Elsevier B.V. All rights reserved.