Heart rate variability in children with type 1 diabetes mellitus

The effect of family history of hypertension and polymorphism of the ACE gene (rs1799752) on cardiac autonomic modulation in adolescents

This study aims to analyze the behaviour of cardiac autonomic modulation in adolescents with a family history of hypertension along with polymorphism of the ACE gene (rs1799752). The study involved 141 adolescents, with a mean age of 14.89, divided into the following six groups: offspring of normotensive parents (ONP): DD, DI and II; and offspring of hypertensive parents (OHP): DD, DI and II. Blood pressure, body composition, family history of hypertension, sleep disorder, and sexual maturation were assessed for the groups' characterization. Afterwards, an electrocardiogram was performed, and oral mucosal cells were collected to analyze heart rate variability and genotypic research of angiotensin-converting enzyme. The main finding of this study was the decrease of vagal action in group OHP (genotype DD) relative to group ONP (genotype II): LF (%), 54.25 ± 3.14 vs 39.33 ± 3.80; HF (%), 45.74 ± 3.14 vs 60.66 ± 3.80; LF/HF, 1.48 ± 0.23 vs 0.68 ± 0.19. The results also showed changes in the variable diastolic blood pressure (DBP) in OHP (genotype DI) to ONP (genotype II) groups: 72.99 ± 2.33 vs 63.27 ± 1.72; and OHP (genotype DI) to ONP (genotype DD) groups. Adolescents with genotype DD and a family history of arterial hypertension present chances in cardiac autonomic modulation, the cardiac parasympathetic modulation is lower in these adolescents in comparison to participants of ONP + II group.

Sounds of Silence in Times of COVID-19: Distress and Loss of Cardiac Coherence in People With Misophonia Caused by Real, Imagined or Evoked Triggering Sounds

The extreme, unprecedented situations in the current COVID-19 pandemic are risk factors for psychosocial stress for the entire population. However, strict confinement had a particular impact on people suffering from misophonia and their families. Misophonia is a condition in which hearing certain sounds triggers intense anger, disgust and even severe autonomic nervous system responses. This prospective cohort study examined the impact of strict confinement (Spain, March 14-June 21, 2020) on a sample of 24 people (16 women and eight men) who had been diagnosed with moderate to extreme misophonia and were regularly attending a medical psychology center in Barcelona. The 3-month period of confinement caused general emotional maladjustment, distress, and a transitory crisis. Long-term biomonitoring of their heart variability rate (HRV) enabled to identify a significant increase in physiological arousal after the confinement period, which had already been recorded in a loss of cardiac coherence under basal rest/relaxation conditions. Certain auditory stimuli triggered adverse responses, lowered HRV scores, and an increased stress level and heart rate. Loss of cardiac coherence in their responses to these auditory stimuli (triggering mouth, nose and other sounds), as well as to non-triggering mouth, nose and other sounds was increased when compared to two assessments performed during the previous year. Despite the limited sample size, sex differences were observed in the incidence. Loss of cardiac coherence worsened with the severity of the misophonia. Most importantly, imagined or evoked triggering sounds, as well as real ones, were enough to cause the aversive responses, as displayed by the increased loss of cardiac coherence with respect to the at-rest basal level. A semi-structured interview revealed the exceptional nature of the situations, increased hyper-sensorial sensitivity, fear of being infected with or dying from COVID-19, the patients' coping strategies, and the difficulties and constraints they faced. Finally, the article gives recommendations for better management of misophonia. Improved knowledge of this disorder would help address the current lack of health and social care, hopefully preventing this shortfall's impact on social and affective relationships, which are particulary important for well-being now and in the coming periods of physical distancing measures.

Relationship between Vascular Resistance and Sympathetic Nerve Fiber Density in Arterial Vessels in Children With Sleep Disordered Breathing

Background

Sleep disordered breathing in children is associated with increased blood flow velocity and sympathetic overactivity. Sympathetic overactivity results in peripheral vasoconstriction and reduced systemic vascular compliance, which increases blood flow velocity during systole. Augmented blood flow velocity is recognized to promote vascular remodeling. Importantly, increased vascular sympathetic nerve fiber density and innervation in early life plays a key role in the development of early‐onset hypertension in animal models. Examination of sympathetic nerve fiber density of the tonsillar arteries in children undergoing adenotonsillectomy for Sleep disordered breathing will address this question in humans.

Methods and Results

Thirteen children scheduled for adenotonsillectomy to treat sleep disordered breathing underwent pupillometry, polysomnography, flow‐mediated dilation, resting brachial artery blood flow velocity (velocity time integral), and platelet aggregation. The dorsal lingual artery (tonsil) was stained and immunofluorescence techniques used to determine sympathetic nerve fiber density. Sympathetic nerve fiber density was correlated with increased resting velocity time integral (r=0.63; P<0.05) and a lower Neuronal Pupillary Index (r=−0.71, P<0.01), as well as a slower mean pupillary constriction velocity (mean, r=−0.64; P<0.05). A faster resting velocity time integral was associated with a slower peak pupillary constriction velocity (r=−0.77; P<0.01) and higher platelet aggregation to collagen antigen (r=0.64; P<0.05). Slower mean and peak pupillary constriction velocity were associated with higher platelet aggregation scores (P<0.05; P<0.01, respectively).

Conclusions

These results indicate that sympathetic activity is associated with change in both the function and structure of systemic vasculature in children with sleep disordered breathing.