Cardiovascular autonomic nervous function in children conceived by assisted reproductive technology with frozen or fresh embryo transfer.

As a result of epigenetic changes, children conceived by assisted reproduction may be at risk of premature cardiovascular aging with notably increased blood pressures. Their cardiovascular autonomic nervous function is unknown. Therefore, this study investigated the cardiovascular autonomic nervous function in 8-12-yr-old children (51% girls) conceived naturally (n = 33) or by assisted reproduction with frozen (n = 34) or fresh (n = 38) embryo transfer by evaluating heart rate variability, during rest; from provocation maneuvers; and from baroreflex function. Heart rate and blood pressure response to provocation maneuvers and baroreflex function were comparable between children conceived naturally or by assisted reproduction. The mean RR-interval and high-frequency component of heart rate variability were lower in children conceived by assisted reproduction than in children conceived naturally. Children conceived by fresh embryo transfer had ∼17% lower heart rate-corrected standard deviation of normal-to-normal R-R intervals; ∼22% lower heart rate-corrected square root of the mean of the squared difference between successive R-R intervals; and ∼37% higher low-frequency/high-frequency ratio than naturally conceived children. Children conceived by assisted reproduction still had lower heart rate variability and vagal modulation than naturally conceived children after adjustment for confounders. Thus, these results raise the possibility of sympathetic predominance in children conceived by assisted reproduction. Therefore, it is important to reproduce these results in larger and older cohorts as sympathetic predominance relates with cardiovascular and metabolic diseases.NEW & NOTEWORTHY We observed that children conceived by assisted reproductive technology (both frozen and fresh embryo transfer) had lowered heart rate variability during rest as compared with children conceived naturally. During physiological stress maneuvers, however, the cardiovascular autonomic nervous regulation was comparable between children conceived by assisted reproductive technologies and naturally. Our findings highlight the potential that lowered heart rate variability during rest in children conceived by assisted reproductive technologies may precede premature hypertension.

The Effect of Exercise on Cardiovascular Autonomic Nervous Function in Patients with Diabetes: A Systematic Review.

BACKGROUND: Diabetic neuropathy, including autonomic neuropathy, is a severe complication in patients with poorly controlled diabetes. Specifically, cardiovascular autonomic neuropathy (CAN) plays a significant prognostic role in cardiovascular morbidity and mortality. Exercise, an essential component of diabetes treatment, may have a therapeutic effect on patients with diabetes complicated by CAN. However, it remains unclear whether exercise has a therapeutic or protective effect in diabetes patients with CAN. METHODS: The author conducted a systematic search of PubMed/MEDLINE, Embase, and The Cochrane Library, resulting in the identification of eight eligible randomized controlled trials for this review. RESULTS: Exercise, including aerobic exercise combined with resistance training (RT), high-intensity interval training, and progressive RT, has shown a beneficial effect on cardiac autonomic function (CAF) in patients with type 2 diabetes, as measured by heart rate variability, heart rate recovery, and baroreflex sensitivity. However, most studies had low quality. Moreover, there were no relevant studies examining the effect of exercise on CAF in older patients, patients with poorly controlled diabetes, and patients with type 1 diabetes. CONCLUSIONS: Exercise has the potential to manage patients with CAN by balancing sympathetic and parasympathetic nervous system functions; however, further studies are warranted in the future.

[Effect of acupuncture-moxibustion stimulation of combined "Biao-Ben" acupoints on autonomic nervous activity and related factors in rats with irritable bowel syndrome diarrhea].

OBJECTIVE: To observe the effect of acupuncture and moxibustion of the combined "Biao-Ben" acupoints on autonomic nervous function and related factors in rats with irritable bowel syndrome diarrhea (IBS-D). METHODS: Female SD rats were randomly divided into normal control, IBS-D model, "Biao-Ben" acupoint combination, and conventional acupoint combination groups, with 10 rats in each group. The IBS-D model was established by repeated chronic stress stimulation (water or food deprivation, painful tail pinching, exposure to a 43 ℃ environment, forced swimming in 4 ℃ water, day-night inversion and horizontal vibration) for 28 d, and followed by acute restraint stress (wrapping of shoulders, forelimbs and trunk) for 1 h and gavage of senna fluid, once daily for 28 d. For rats of the "Biao-Ben" acupoint combination group, acupuncture and moxibustion were applied to "Guanyuan" (CV4), bilateral "Zusanli" (ST36), and "Neiguan" (PC6), and for rats of the conventional acupoint combination group, acupuncture and moxibustion were applied to bilateral ST36, "Tianshu"(ST25), and "Shangjuxu"(ST37). Both acupuncture and suspension moxibustion treatment were conduced for 15 min, once daily for 21 days. The fecal water content was calculated, and the spontaneous activity behaviors (total distance of crossing and the number of squares crossed in 5 min) were evaluated by open-field tests. The abdominal withdrawal reflex (AWR) was detected. H.E. staining was used to observe the histopathological changes of colon tissue. The domains of heart rate variability (HRV) including low frequency (LF), high frequency (HF), and LF/HF were analyzed using an electrophysiological recorder. The contents of calcitonin gene-related peptide (CGRP) in serum and noradrenaline (NE) in plasma were detected using ELISA. The expression level and immunoactivity of 5-hydroxytryptamine (5-HT) in colon tissues were detected by Western blot and immunofluorescence histochemistry, separately. RESULTS: Compared with the normal group, the model group had a striking increase in fecal water content, AWR scores at 20, 40, 60, and 80 mm Hg, NE and CGRP contents, LF, LF/HF, and 5-HT protein expression and immunoactivity (P<0.01), and an obvious decrease in the total distance of crossing, the number of squares crossed, and HF of HRV (P<0.01). In comparison with the model group, the fecal water content, AWR scores at 20, 40, 60, and 80 mm Hg, NE and CGRP contents, LF, LF/HF, and 5-HT protein expression and immunoactivity were significantly decreased (P<0.01,P<0.05), while the total distance of cros-sing, number of squares crossed, HF of HRV were considerably increased (P<0.01, P<0.05) in both "Biao-Ben" acupoint combination and conventional acupoint combination groups. The effects of the "Biao-Ben" acupoint combination were apparently superior to those of conventional acupoint combination in down-regulating the fecal water content, AWR score at 20, 40, 60 and 80 mm Hg, NE and CGRP contents, LF, LF/HF, and 5-HT expression and immunoactivity, and in increasing the number of squares crossed, and HF of HRV (P<0.01, P<0.05). HE staining showed no pathological changes in colonic mucosa in all groups. CONCLUSION: Acupuncture and moxibustion stimulation of combined "Biao-Ben" acupoints can effectively improve the symptoms (spontaneous activities, visceral hypersensitivity) of IBS-D model rats, which may be related to its functions in regulating autonomic nervous activities, and down-regulating blood NE and CGRP contents and colonic 5-HT protein expression and immunoactivity, and the effects of "Biao-Ben" acupoint combination are superior to those of conventional acupoint combination.

Clinical efficacy and mechanism of transcutaneous neuromodulation on ineffective esophageal motility in patients with gastroesophageal reflux disease.

BACKGROUND: Esophageal motility disorder is one of the pathogenesis of gastroesophageal reflux disease (GERD). The clinical and functional relationship between the ineffective esophageal motility (IEM) and GERD have been found. PPI is a widely used drug of this diaease, but some patients have poor efficacy. The purpose of this study was to investigate the efficacy and possible mechanism of Transcutaneous Neuromodulation in these patients. METHODS: Fifty-six patients with GERD with IEM were enrolled and randomly divided into two groups, one group was TN ST-36 group, the other group was sham TN group. The GERD questionnaire (GerdQ), quality of life score, MOS item short from health survey (SF-36), Hospital Anxiety and Depression Scale (HADS) were used to assess the severity of symptoms. High-resolution esophageal manometry (HRM) test was performed to assess low esophageal sphincter (LES) pressure and distal contractile integral (DCI). The heart rate variability (HRV) test was performed to assess autonomic nervous function. KEY RESULTS: Compared with sham TN, chronic TN treatment decreased the GERD-Q score (p < 0.001). The anxiety score (p = 0.058) and depression score (p = 0.156) were decreased, but there were no statistical differences. Chronic TN treatment also significantly improved the quality of life of patients, mainly in physical function, physical pain, overall health, vitality, social function, emotional function, and mental health. Acute TN treatment increased the DCI (p < 0.001) and LES pressure (p < 0.001) significantly and decreased the combined percentage of failed and weak peristalsis (p < 0.001). Concurrently, acute TN enhanced vagal activity (p < 0.001). CONCLUSIONS AND INFERENCES: IEM is an important link in the pathogenesis of GERD. Chronic TN treatment can significantly improve the clinical symptoms of patients. Acute TN treatment can significantly increase LES pressure and DCI and reduce the frequency of esophageal lost peristalsis and weak peristalsis. The improvement of esophageal motility in GERD patients with IEM by TN treatment may be related to the regulation of autonomic nervous function.

Effect of resistance training on heart rate variability of anxious female college students.

Introduction: Female college students are a group with high incidence of anxiety, and anxiety will lead to the disorder of autonomic nervous system (ANS), which will adversely affect their study and life. Resistance training plays a positive role in improving anxiety, but there is little evidence on whether resistance training can improve ANS of anxious female college students. Heart rate variability (HRV) has gained widespread acceptance in assessing ANS modulation. Therefore, the objective of this study aimed to investigate the effects of resistance training on heart rate variability (HRV) in anxious female college student. Methods: A randomized controlled study of resistance training intervention was conducted in 27 anxious female college students that assigned randomly into an intervention group (n = 14) and a control group (n = 13). The intervention group was intervened by cluster training for 8 weeks. Self-rating anxiety scale (SAS) was used. ANS is evaluated by short-term HRV. Muscle strength was assessed by 1 RM indirect method. Independent-sample t-test was used to test post-test-pre-test scores between the intervention and control groups. Results: After the intervention, SAS score of the intervention group was significantly decreased (P < 0.05), SDNN of the intervention group was significantly increased (P < 0.05) and LF/HF was significantly decreased (P < 0.05). Conclusion: The resistance training intervention adopted in this study significantly increased the HRV of anxious female college students and improved their autonomic nervous disorder.

The Relationship Between Unexplained Chest Pain in Children and Head-Up Tilt Test.

Background: To explore the relationship between unexplained chest pain in children and head-up tilt test (HUTT). Materials and Methods: A total of 825 children with the main symptom of unexplained chest pain were admitted to the Specialist Outpatient Clinic of Children's Cardiovascular Disease from October 2000 to November 2021 at The Second Xiangya Hospital, Central South University. Among them, 473 were male and 352 were female, with a mean age of 10.61 ± 2.21 years. The control group included 58 cases, comprising 35 males and 23 females, with a mean age of 10.26 ± 2.66 years. The detailed history, physical examinations, conventional 12-lead electrocardiogram, chest X-ray, echocardiography, myocardial enzymes, electroencephalogram, and blood series were all examined. Disorders of the chest wall, lung, heart, mediastinum, and esophageal reflux, as well as drug effects, were ruled out. All the children underwent HUTT. Demographic description, univariate analysis, and multivariate logistic regression analysis were used to explore the possible linear or non-linear relationships between the children's unexplained chest pain and HUTT. Results: Among the 825 chest pain cases, 301 (36.48%) were HUTT positive and 524 (63.52%) were HUTT negative. HUTT-positive patients were older than HUTT-negative patients (11.04 ± 2.03 vs. 10.34 ± 2.31 years, P < 0.001). The logistic regression results showed that each year of age increased the probability of being HUTT positive by 17.90% (P < 0.000), and females were 91.30% more likely to be HUTT positive than males (P < 0.000). Conclusion: Clinically unexplained chest pain in children is mainly caused by unbalanced autonomic nervous function. HUTT can help clear the cause of unexplained chest pain.

[Effect of transcutaneous auricular vagus nerve stimulation on nocturnal autonomic nervous function in primary insomnia patients].

OBJECTIVE: To observe the effect of transcutaneous auricular vagus nerve stimulation (taVNS) on the sleep quality and nocturnal heart rate variability (HRV) in patients with primary insomnia. METHODS: Twenty-one patients with primary insomnia were included. Using SDZ-ⅡB electric acupuncture apparatus, Xin (CO15) and Shen (CO10) were stimulated with disperse-dense wave, 4 Hz/ 20 Hz in frequency, (0.2±30%) ms of pulse width and tolerable intensity. Electric stimulation was given once every morning and evening of a day, 30 min each time, for 4 weeks totally. Before and after treatment, the score of Pittsburgh sleep quality index (PSQI), objective sleep structure (total sleep time [TST], sleep latency [SL], wake after sleep onset [WASO], sleep efficiency [SE], the percentages of non-rapid eye movement period 1, 2, 3, and the percentage of rapid eye movement period to TST [N1%, N2%, N3%, REM%] ) and nocturnal HRV (high frequency [HF], low frequency [LF], the ratio of LF to HF [LF/HF], standard deviation for the normal RR intervals [SDNN], squared root of the mean sum of squares of differences between adjacent intervals RR [RMSSD], the percentage of adjacent RR intervals with differences larger than 50 ms in the entire recording [PNN50%], the mean of sinus RR intervals [NNMean] ) were compared in the patients separately. RESULTS: After treatment, the score of each item and the total score of PSQI and SL were all reduced as compared with those before treatment (P<0.01, P<0.001); SE, N3%, LF, HF, LF/HF, SDNN, NNMean and RMSSD were all increased compared with those before treatment (P<0.001, P<0.01). CONCLUSION: The taVNS improves the sleep quality and objective sleep structure in patients with primary insomnia, which is probably related to the regulation of autonomic nervous functions.

Effect of napping on a bean bag chair on sleep stage, muscle activity, and heart rate variability.

Background: Although ample evidence has demonstrated that daytime napping is beneficial for health and cognitive performance, bedding for napping has not yet been scientifically investigated. Objectives: To explore the effect of a bean bag chair on daytime napping and physiological parameters related to sleep. Methods: Fourteen healthy participants were enrolled within the context of a randomized, single-blind, crossover study to evaluate the effects of a bean bag chair in comparison with those of a urethane chair manufactured to have a similar shape. Electroencephalogram, electromyogram, and heart rate variability were recorded and compared between wakefulness and napping. Results: Electroencephalogram analyses revealed no significant differences in sleep architecture or frequency components; however, a significant decrease was found in electromyogram recordings in the trapezius muscle, which represents the neck region (p = 0.019). Additionally, a significant main effect of bedding in the low-frequency/high-frequency ratio (F[1,20] = 4.314, p = 0.037) was revealed. Conclusions: These results suggest that napping in a bean bag chair may provide a comfortable napping environment involving muscle relaxation and proper regulation of the autonomic nervous function.

Effect of transcutaneous auricular vagus nerve stimulation on nocturnal autonomic nervous function in primary insomnia patients / 中国针灸

OBJECTIVE@#To observe the effect of transcutaneous auricular vagus nerve stimulation (taVNS) on the sleep quality and nocturnal heart rate variability (HRV) in patients with primary insomnia.@*METHODS@#Twenty-one patients with primary insomnia were included. Using SDZ-ⅡB electric acupuncture apparatus, Xin (CO15) and Shen (CO10) were stimulated with disperse-dense wave, 4 Hz/ 20 Hz in frequency, (0.2±30%) ms of pulse width and tolerable intensity. Electric stimulation was given once every morning and evening of a day, 30 min each time, for 4 weeks totally. Before and after treatment, the score of Pittsburgh sleep quality index (PSQI), objective sleep structure (total sleep time [TST], sleep latency [SL], wake after sleep onset [WASO], sleep efficiency [SE], the percentages of non-rapid eye movement period 1, 2, 3, and the percentage of rapid eye movement period to TST [N1%, N2%, N3%, REM%] ) and nocturnal HRV (high frequency [HF], low frequency [LF], the ratio of LF to HF [LF/HF], standard deviation for the normal RR intervals [SDNN], squared root of the mean sum of squares of differences between adjacent intervals RR [RMSSD], the percentage of adjacent RR intervals with differences larger than 50 ms in the entire recording [PNN50%], the mean of sinus RR intervals [NNMean] ) were compared in the patients separately.@*RESULTS@#After treatment, the score of each item and the total score of PSQI and SL were all reduced as compared with those before treatment (P<0.01, P<0.001); SE, N3%, LF, HF, LF/HF, SDNN, NNMean and RMSSD were all increased compared with those before treatment (P<0.001, P<0.01).@*CONCLUSION@#The taVNS improves the sleep quality and objective sleep structure in patients with primary insomnia, which is probably related to the regulation of autonomic nervous functions.

Loss of Group II Metabotropic Glutamate Receptor Signaling Exacerbates Hypertension in Spontaneously Hypertensive Rats.

High blood pressure is a major risk factor of cerebro-cardiovascular outcomes. Blood pressure is partly regulated by the autonomic nervous system and its reflex functions; therefore, we hypothesized that pharmacological intervention in the brainstem that can regulate blood pressure could be a novel therapeutic strategy to control hypertension. We infused a group II metabotropic glutamate receptor (mGluR) antagonist (LY341495, 0.40 µg/day), using a mini-osmotic pump, into the dorsal medulla oblongata in young spontaneously hypertensive rats (SHRs), as this area is adjacent to the nucleus tractus solitarius (NTS), of which the neurons are involved in baroreflex pathways with glutamatergic transmission. Blood pressure was recorded for conscious rats with the tail cuff method. A 6-week antagonist treatment from 6 to 12 weeks of age slightly but significantly increased systolic blood pressure by >30 mmHg, compared to that in SHRs without treatment. Moreover, the effect continued even 3 weeks after the treatment ended, and concurred with an increase in blood catecholamine concentration. However, heart rate variability analysis revealed that LY341495 treatment had little effect on autonomic activity. Meanwhile, mRNA expression level of mGluR subtype 2, but not subtype 3 in the brainstem was significantly enhanced by the antagonist treatment in SHRs, possibly compensating the lack of mGluR signaling. In conclusion, mGluR2 signaling in the dorsal brainstem is crucial for preventing the worsening of hypertension over a relatively long period in SHRs, through a mechanism of catecholamine secretion. This may be a specific drug target for hypertension therapy.

The prevalence of orthostatic dysregulation among newly graduated female nurses after employment and its associations with autonomic nervous function, stress, and depressive symptoms.

OBJECTIVES: We aimed to examine the prevalence of orthostatic dysregulation among newly graduated female nurses after employment and its associations with autonomic nervous function, stress, and depressive symptoms. METHODS: This follow-up study included 48 newly graduated female nurses (aged 22 ± 3 years) employed in acute care hospitals. The orthostatic dysregulation symptoms were evaluated using a screening checklist. A sit-to-stand test was conducted to assess the autonomic nervous function. Subjective stress and depressive symptoms were determined using a self-administered questionnaire. The data were collected at baseline on the first month and on the seventh month of employment. Statistical differences within groups were analyzed using paired t-test and McNemar's test. The independent associations of orthostatic dysregulation status with stress and depressive symptoms were analyzed using a multivariate logistic regression model. RESULTS: The percentage of individuals who were diagnosed with orthostatic dysregulation increased from 25.0% at baseline to 35.4% at follow-up. Logistic regression analyses revealed that stress and depressive symptoms were closely associated with orthostatic dysregulation status at follow-up, despite a weak association reported at baseline. The participants were categorized according to their orthostatic dysregulation status: among individuals without orthostatic dysregulation at baseline but with orthostatic dysregulation at follow-up, the increase in autonomic nervous activity, as assessed by the coefficient of variation of the R-R intervals, in response to the postural changes was significantly attenuated at follow-up. Furthermore, this group exhibited a significant increase in stress and depressive symptoms. CONCLUSIONS: At 7 months after employment, newly graduated nurses showed a higher prevalence of orthostatic dysregulation in combination with autonomic nervous system modulation, which was accompanied by an increase in stress and depressive symptoms. These observations suggest that the orthostatic dysregulation is associated with poor mental and physical health among newly graduated nurses in the early phase of employment.

Electrocardiogram Characteristics of Different Motor Types of Parkinson's Disease.

AIM: This study aims to investigate the electrocardiogram characteristics of the different motor types of Parkinson's disease. METHODS: The data on 118 patients with Parkinson's disease (PD), who were initially diagnosed in the Outpatient and Inpatient Department, was collected. Among these 118 PD patients, 74 patients were assigned to the PIGD group, while 44 patients were assigned to the TD group, and their clinical features were analyzed, which included age, course, disease classification, and electrocardiogram parameters (PR, QRS, QT interval, and QTC). RESULTS: The QT interval in PD patients was positively correlated with the course of the disease and Hoehn-Yahr stage, and the QT interval in the PIGD group was longer than that in the TD group. CONCLUSION: A prolonged QT interval may indicate a longer disease period and a more severe disease condition.

Heart Rate Variability Analysis in Episodic Migraine: A Cross-Sectional Study.

Objective: It has been reported that autonomic nervous dysfunction is more prevalent in migraineurs. Heart rate variability (HRV) is a commonly used method to evaluate the cardiac autonomic nervous function modulation. However, HRV changes in migraine are still contradictory. The main objective of this study was to explore the potential HRV change patterns in episodic migraine (EM) and whether there were differences in HRV between EM ictal period and the interictal period. Patients and Methods: We conducted a cross-sectional study including 18 patients with EM and 18 age- and sex-matched controls. The characteristics of demographics, some lifestyle factors, and psychological conditions were assessed at baseline. HRVs including time-domain analysis and frequency-domain analysis were performed in all participants. HRV analyses in migraine were recorded not only in the interictal period but also in the ictal period. Results: All the HRV parameters showed a decreased trend in migraine than controls. Time-domain parameters standard deviation of all NN intervals in 24 h (SDNN) and triangular index were significantly lower in the migraine ictal period than controls separately (SDNN, 56.94 ± 22.09 ± 7.76 vs. 135.78 ± 35.16, p < 0.001; triangular index, 12.61 ± 3.20 vs. 22.11 ± 6.90, p < 0.001). Frequency-domain parameter low-frequency power was also lower in the migraine ictal period than controls (351.28 ± 206.71 vs. 559.61 ± 281.24, p = 0.02). SDNN was much lower in the migraine ictal period than migraine interictal period (56.94 ± 22.09 vs. 115.94 ± 46.88, p < 0.001). HRV changes during migraine interictal period did not differ from the control group. The correlation analysis revealed a negative correlation between visual analog scale and HRV parameters in the migraine ictal period (p = 0.04). Conclusions: The present cross-sectional study indicates that HRV was significantly decreased in EM population especially during the migraine ictal period, which means unbalance of autonomic system in EM. Perhaps larger prospective cohort studies are wanted to validate these findings.

Vitamin D Deficiency and Vasovagal Syncope in Children and Adolescents.

Aims: To investigate the association of vitamin D deficiency with cardiovascular autonomic nervous system function in children and adolescents with vasovagal syncope (VVS). Methods: This study recruited 76 pediatric patients with VVS and 15 healthy children. The 25-hydroxyvitamin D levels in serum among the participants were evaluated. Heart rate variability analysis including SDNN, rMSSD, and SDANN was tested in patients with VVS. The correlation between indices of time-domain analysis and serum vitamin D status of the children with VVS was investigated. Results: In this work, 25-hydroxyvitamin D levels in serum among VVS cases remarkably decreased compared with those among healthy controls (48.76 ± 19.25 vs. 67.62 ± 15.46 nmol/L, p < 0.01). The vitamin D deficient patients with VVS exhibited a lower rMSDD value compared to the non-deficient group with VVS (45.56 ± 16.87 vs. 61.90 ± 20.38 ms, p < 0.001, respectively). Pearson correlation analysis indicated that serum 25-hydroxyvitamin D levels had positive correlation with rMSDD values (r = 0.466, p < 0.001). Conclusions: As suggested by our data, VVS children and adolescents with vitamin D deficiency may have cardiac autonomic dysfunction and cardiac vagal tone decreases with the reduction in vitamin D level.

The acute effects of temperature variability on heart rate variability: A repeated-measure study.

BACKGROUND: The impacts of temperature variability on cardiac autonomic function remain unclear. OBJECTIVE: To explore the short-term associations between daily temperature variability and parameters of heart rate variability (HRV). METHODS: This is a repeated-measure study among 78 eligible participants in Shanghai, China. We defined temperature variability as diurnal temperature range (DTR), the standard-deviation of temperature (SDT) and temperature variability (TV). We evaluated 3 frequency-domain HRV parameters (VLF, LF and HF) and 4 time-domain parameters (SDNN, SDANN, rMSSD and pNN50). We used linear mixed-effect models to analyze the data after controlling for environmental and individual confounders. RESULTS: Temperature variability was significantly associated with decreased HRV, especially on the concurrent day. The exposure-response relationships were almost inversely linear for most parameters. Every one interquartile range (IQR) increase of DTR was associated with a decrease of 3.92% for VLF, 6.99% for LF, 5.88% for HF, 3.94% for rMSSD and 1.30% for pNN50. Each IQR increase of SDT was associated with a decline of 6.48% for LF, 5.91% for HF, 4.26% for rMSSD and 1.87% for pNN50. Every IQR increase of SDT was associated with a decrease of 4.39% for VLF, 7.67% for LF, 6.52% for HF, 3.22% for SDNN, 2.98% for SDANN, 4.05% for rMSSD, and 1.41% for pNN50. The decrements in HRV associated with temperature variability were more prominent in females. CONCLUSION: Temperature variability on the concurrent day could significantly decrease cardiac autonomic function, especially in females.

Effects of inspiratory muscle training on cardiac autonomic nervous function and the life quality of elderly women / 中华物理医学与康复杂志

Objective:To explore the effect of inspiratory muscle training (IMT) on cardiac autonomic nerve function and the life quality of elderly women.Methods:Fifty-six healthy women aged 60 to 70 were randomly divided into an IMT group and a placebo control group (PLA), each of 28. The IMT group was given IMT training 5 times a week for 5 weeks with the inspiratory resistance set at 50% of their maximum inspiratory pressure (MIP). The PLA group was treated similarly, but the inspiratory resistance was set at the 5% of the MIP. Before and after the intervention, both groups were evaluated in terms of heart rate variability (HRV) at rest, and heart rate during the inspiratory phase (HR-in) and expiratory phase (HR-ex) of deep breathing. Their quality of like was quantified using the World Health Organization′s quality of life scale (WHOQOL-100).Results:After the intervention, the average MIP and high frequency power in the HRV spectrum had increased significantly, but the ratio of low frequency to high frequency power had decreased significantly in the IMT group. In deep breathing the average HR-in and HR-ex both had decreased significantly. The average scores on all dimensions of the WHOQOL-100 were significantly higher than before the intervention and higher than those of the control group. Indeed, there were no significant differences in the PLA group′s results before and after the intervention.Conclusions:Five weeks of IMT training can significantly improve the cardiac autonomic nerve function and life quality of elderly women. This provides a reference for prescribing rehabilitation exercise for such women.

A Novel Smartphone App for the Measurement of Ultra-Short-Term and Short-Term Heart Rate Variability: Validity and Reliability Study.

BACKGROUND: Smartphone apps for heart rate variability (HRV) measurement have been extensively developed in the last decade. However, ultra-short-term HRV recordings taken by wearable devices have not been examined. OBJECTIVE: The aims of this study were the following: (1) to compare the validity and reliability of ultra-short-term and short-term HRV time-domain and frequency-domain variables in a novel smartphone app, Pulse Express Pro (PEP), and (2) to determine the agreement of HRV assessments between an electrocardiogram (ECG) and PEP. METHODS: In total, 60 healthy adults were recruited to participate in this study (mean age 22.3 years [SD 3.0 years], mean height 168.4 cm [SD 8.0 cm], mean body weight 64.2 kg [SD 11.5 kg]). A 5-minute resting HRV measurement was recorded via ECG and PEP in a sitting position. Standard deviation of normal R-R interval (SDNN), root mean square of successive R-R interval (RMSSD), proportion of NN50 divided by the total number of RR intervals (pNN50), normalized very-low-frequency power (nVLF), normalized low-frequency power (nLF), and normalized high-frequency power (nHF) were analyzed within 9 time segments of HRV recordings: 0-1 minute, 1-2 minutes, 2-3 minutes, 3-4 minutes, 4-5 minutes, 0-2 minutes, 0-3 minutes, 0-4 minutes, and 0-5 minutes (standard). Standardized differences (ES), intraclass correlation coefficients (ICC), and the Spearman product-moment correlation were used to compare the validity and reliability of each time segment to the standard measurement (0-5 minutes). Limits of agreement were assessed by using Bland-Altman plot analysis. RESULTS: Compared to standard measures in both ECG and PEP, pNN50, SDNN, and RMSSD variables showed trivial ES (<0.2) and very large to nearly perfect ICC and Spearman correlation coefficient values in all time segments (>0.8). The nVLF, nLF, and nHF demonstrated a variation of ES (from trivial to small effects, 0.01-0.40), ICC (from moderate to nearly perfect, 0.39-0.96), and Spearman correlation coefficient values (from moderate to nearly perfect, 0.40-0.96). Furthermore, the Bland-Altman plots showed relatively narrow values of mean difference between the ECG and PEP after consecutive 1-minute recordings for SDNN, RMSSD, and pNN50. Acceptable limits of agreement were found after consecutive 3-minute recordings for nLF and nHF. CONCLUSIONS: Using the PEP app to facilitate a 1-minute ultra-short-term recording is suggested for time-domain HRV indices (SDNN, RMSSD, and pNN50) to interpret autonomic functions during stabilization. When using frequency-domain HRV indices (nLF and nHF) via the PEP app, a recording of at least 3 minutes is needed for accurate measurement.

Early attenuation of autonomic nervous function in senescence accelerated mouse-prone 8 (SAMP8).

The senescence-accelerated mouse (SAM) strain has been established as an inbred strain with an accelerated aging phenotype. SAM prone-8 (SAMP8), one of the SAM strain, exhibits learning disability, immune deficiency, and circadian rhythm loss at a relatively young age. However, it has not been clarified whether aging affects the autonomic nervous activity in SAMP8. The aim of this study was to clarify the utility of SAMP8 in age-related studies of autonomic nervous function. Electrocardiogram (ECG), body temperature, and locomotor activity were recorded to evaluate bio-behavioral activities. Autonomic nervous activity was evaluated via power spectral analysis of heart rate variability from ECG recordings. SAMP8 significantly decreased both biological and autonomic nervous functions, and the animals exhibited circadian rhythm loss of locomotive activity at as early as 40 weeks of age compared with a control strain at the same age. We concluded that the SAMP8 strain can be used as an animal model for age-related studies of autonomic nervous function.

Improvement of glycemic control by treatment for insomnia with suvorexant in type 2 diabetes mellitus.

INTRODUCTION: Acute and chronic insomnia can exacerbate type 2 diabetes mellitus (T2DM). We investigated suvorexant (an anti-insomnia drug that targets the orexin system) effects on sleep architecture and glucose metabolism in T2DM patients with insomnia. MATERIALS AND METHODS: This 7 day open-label, single-arm, intervention trial included 18 subjects with T2DM and insomnia. After 1 day acclimatization, daily glucose levels, sleep architecture, and autonomic nervous function were evaluated by continuous glucose monitoring (CGM), single-channel electroencephalography, and accelerometry, respectively. RESULTS: Suvorexant treatment for 3 days significantly increased total sleep time and sleep efficiency, with partial suppression of sympathetic nerve activity. CGM-measured 24 h mean glucose level decreased significantly from 157.7 ±â€¯22.9 to 152.3 ±â€¯17.8 mg/dL, especially in the early glucose surge after the midnight nadir (from 28.3 ±â€¯15.0 to 18.2 ±â€¯9.9 mg/dL), and until supper with a significant improvement in homeostasis model assessment of insulin resistance from 4.0 ±â€¯2.8 to 2.9 ±â€¯1.6, respectively. CONCLUSIONS: Suvorexant treatment for insomnia of subjects with T2DM significantly improved CGM-measured daily glycemic control, which was associated with changes in sympathomimetic tone and/or improved insulin sensitivity. The amelioration of insomnia may therefore be a target for improving glycemic control in T2DM patients with insomnia.

Changes in heart rate deceleration capacity and variability in resting children with vasovagal syncope / 中华实用儿科临床杂志

Objective To investigate the changes in heart rate deceleration capacity( DC)and heart rate va-riability(HRV)parameters in children with vasovagal syncope(VVS),to assess the basic autonomic function of children with VVS,and to explore the reference value of DC for the diagnosis of VVS in children. Methods VVS group included 62 patients diagnosed with VVS in the Cardiovascular Department of Children＇s Hospital Affiliated to Capital Institute of Pediatrics from June 2015 to December 2017,56 outpatients undergoing physical examination were selected as the healthy control group,and the changes in DC and HRV matched to age and gender were analyzed respectively. Indexes of DC and HRV of both groups of children in health control group and children with VVS were compared among different age groups or different genders. Results (1)Analysis of DC and HRV based on age or gender:whether in healthy children or in children with VVS,DC and HRV parameters varied significantly in the range of different ages,while they were the same in children with different genders.(2)Comparison of DC and HRV in school-age and puberty children between VVS group and healthy control group:in school-aged children,DC of VVS group was significantly higher than that of healthy control group[(6. 8 ± 1. 0)ms υs.(6. 0 ± 0. 7)ms,t= -2. 412,P<0. 01]. Mean square root rates of succe-ssive normal sinus RR interval differences(rMSSD)increased,and the difference was significant( P<0. 05). In chil-dren at puberty,DC in children of VVS group was significantly higher than that in the healthy control group[(7. 4 ± 1. 2)ms υs.(6. 6 ± 1. 1)ms,t= -2. 742,P<0. 01],rMSSD,LF and HF value were significantly higher compared with those of the healthy control group(all P<0. 05).(3)Predictive value of DC on VVS:the binary Logistic regression analysis found that only DC was associated with VVS in different age groups. By using receiver operating characteristic curve to analyze the predictive value of DC on VVS,it was found that when making DC 6. 5 ms for school age and 7. 0 ms at puberty as the threshold,a better prediction of VVS could be achieved with good sensitivity and specificity. Conclusions Children＇s autonomic nervous function changes with age,and DC and HRV parameters change signifi-cantly during adolescence and at school age. Children with VVS may have abnormally increased vagal tone. When DC≥6. 5 ms at school age or DC≥7. 0 ms at puberty,it may have a reference value for the diagnosis of VVS.