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

Interaction between Autonomic Regulation, Adiposity Indexes and Metabolic Profile in Children and Adolescents with Overweight and Obesity

Early obesity predicts initial modifications in cardiac and vascular autonomic regulation. The aim of this study was to assess the possible interaction between non-invasive measures of autonomic cardiovascular control and peripheral endothelium regulation in children with overweight and obesity. We involved 114 young subjects (77M/37F, 12.7 ± 2.2 years) with normal weight (NW, n = 46) to overweight or obesity (OB, n = 68). Multivariate statistical techniques utilizing a collection of modern indices of autonomic regulation, adiposity indexes and metabolic profile were employed. Resting values show substantial equivalence of data. Conversely, blood pressure variance is greater in NW/OB groups. The correlation matrix between major autonomic and metabolic/hemodynamic variables shows a clustered significant correlation between homogeneous indices. A significant correlation between metabolic indices and endothelial and autonomic control, mostly in its vascular end, was recorded. Particularly, the alpha index is significantly correlated with triglycerides (r = −0.261) and endothelial indices (RHI, r = 0.276). Children with obesity show a link between indices of autonomic and endothelial function, fat distribution and metabolic profile. The optimization of autonomic control, for instance by exercise/nutrition interventions, could potentially prevent/delay the occurrence of structural vascular damage leading to reduced cardiovascular health.

Impact of acute mental stress on segmental arterial stiffness

PURPOSE

It has been reported that acute brief episodes of mental stress (MS) result in a prolonged increase in carotid-femoral pulse wave velocity (cfPWV), an index of aortic stiffness. However, whether acute MS also impacts arterial stiffness in other segments is unclear. The present study aimed to examine the impact of acute MS on segmental arterial stiffness.

METHODS

In the main experiment, 17 young male subjects (mean age, 20.1 ± 0.7 years) performed a 5-min MS and control (CON) task in a random order. Pulse wave velocity (PWV) from the heart to the brachium (hbPWV) and the ankle (haPWV), PWV between the brachial artery and the ankle (baPWV), and the cardio-ankle vascular index (CAVI) were simultaneously measured at baseline and 5, 15, and 30 min after the task.

RESULTS

Compared to baseline values, hbPWV, baPWV, haPWV, and CAVI significantly increased until 30 min after the MS task, whereas these variables did not significantly change following the CON task. At 5 and 30 min after the MS task, percentage changes from baseline were significantly higher in hbPWV (+ 5.2 ± 4.4 and 6.6 ± 4.9%) than in baPWV (+ 2.2 ± 2.1 and 2.2 ± 2.0%) or haPWV (+ 3.6 ± 2.6 and 4.3 ± 2.9%) and were also significantly lower in baPWV than in haPWV.

CONCLUSION

These findings suggest that acute MS elicits an increase in arterial stiffness in various segments and this arterial stiffening is not uniform among the segments.

Cardiorespiratory optimization during improvised singing and toning

We evaluated the effect of different forms of singing on cardiorespiratory physiology, and we aimed at disentangling the role of breathing from that of vocal production. Cardiorespiratory recordings were obtained from 20 healthy adults at rest and during: a) singing of familiar slow songs as in the standard form of Western culture; b) improvised vocalization of free vowel sounds, known as toning. To disentangle the role of breathing from that of vocal production, we compared the vocal conditions with matched breathing-only conditions. Toning significantly improved heart rate variability, ventilatory efficiency and slowed respiration to almost exactly six breaths per minute (p < 0.001), a pattern that is known to optimize cardiovascular function and that coincides with the period of endogenous circulatory rhythms. Singing songs also positively impacted cardiorespiratory function, although to a lesser extent. The breathing pattern imposed upon participants in the absence of vocal production was sufficient to generate the physiological benefits. The effects of toning are similar to what has been previously described as a result of engaging in formal breathing exercises. Toning and singing may offer an engaging and cost effective tool to trigger beneficial respiratory patterns and the related cardiovascular benefits.