Changes in heart-rate variability of survivors of nasopharyngeal cancer during Tai Chi Qigong practice

Social Isolation, Loneliness, and Cardiovascular Mortality: The Role of Health Care System Interventions

PURPOSE OF REVIEW

The world is proliferating rapidly, with science and technology advancing at an incredible rate. These advances have, however, ushered in an age with a rise in social isolation (SI) and loneliness. SI is an objective term that refers to lacking social contact or support. On the other hand, loneliness is subjective and refers to feeling alone or isolated. These concepts are rapidly gaining prominence mainly due to their negative impact on the physical and psychological health of the population, mainly through behavioural modifications that encompass substance abuse, decreased physical activity and unhealthy food habits, and poor sleep hygiene. This review summarizes the pathophysiology, evaluates the evidence behind impact of SI on cardiovascular mortality, and interventions to overcome SI.

RECENT FINDINGS

Through proposed mechanisms, such as activation of the sympathetic nervous system and the hypothalamic-pituitary-adrenal axis, both SI and loneliness have strong evidence linking them to cardiovascular morbidity and mortality. A systematic review and meta-analysis of 90 prospective cohort studies including 2,205,199 individuals reported that SI was independent predictor of cardiovascular mortality with a point estimate of 1.34 (95% confidence interval:1.25-1.44). The evidence so far is compelling and necessitates urgent action with the implementation of strict policies to tackle this issue. As healthcare professionals, it becomes even more critical to remain vigilant, recognize this insidious pandemic, and take appropriate action.

Effect of a 16-Session Qigong Program in Non-Hodgkin Lymphoma Survivors: A Randomized Clinical Trial

Background: The treatment associated with non-Hodgkin lymphoma patients may cause adverse effects on their physical and psychological condition. The aim of this study is to detect the response to an eight-week, 16-session, 60-min presential Qigong program in anxiety, depression and vagal nerve activity alongside a control group. Methods: A randomized controlled clinical trial was managed. Randomization was carried out by generating a numerical sequence of three cycles through the software EPIDAT 4.1. Numbers were placed in sealed opaque envelopes for assignment to the different groups. Results: Anxiety levels were substantially decreased in the experimental group, with a large effect size (F = 30.38, p < 0.00). Depression levels had an improvement in the experimental group in contrast to the control group, reaching statistical significance (F = 19.19, p < 0.00). Heart Rate Variability unveiled significant results in terms of between-group differences, with a large effect size in the HRV Index (F = 15.80, p < 0.00), SDNN (F = 8.82, p < 0.00), and RMSSD (F = 6.72, p < 0.01) in the time domain, and a medium effect size in the HF (F = 9.78, p < 0.003), LF (F = 9.78, p < 0.00), and LF/HF Ratio (F = 18.44, p < 0.00) in the frequency domain, which were all bettered in the experimental group, after the Qigong program. Conclusions: Qigong therapy can be an effective therapeutic activity in consonance with traditional medicine to improve psychological health and autonomic nervous system balance in non-Hodgkin lymphoma survivors.

Cardiac Autonomic Modulation in Response to Three Types of Exercise in Patients with Type 2 Diabetic Neuropathy

Purpose

Physical exercise is necessary in the handling DM, but it is not distinct which kind of physical exercise can improve cardiac autonomic modulation in T2DM. The purpose of this study was to compare the effects of three different modalities of exercise (aerobic, resistant, and combined) on cardiac autonomic modulation as measured by HRV in patients with type 2 diabetic neuropathy.

Methods

The participants were 45 men (age: 55.24 ± 8.11 years, weight: 89.5 ± 13.4 kg, height: 171.85 ± 6.98 cm, duration of diabetes: 12.51 ± 6.46 years) with type 2 diabetic neuropathy who were clinically free from signs and symptoms of cardiovascular disease. Participants were randomly assigned to one of four groups: aerobic-training (n = 11), dynamic resistant-training (n = 11), Combined-training (n = 11), or a non-exercise control group (n = 12). The exercise groups performed aerobic and resistant exercise for 25-45 min per day, 3-5 times per week for 12 weeks. Anthropometrics, biochemical markers (FBS, HbA1c, Lipid Profile, and Insulin), and heart rate variability in the exercise laboratory and under ambulatory conditions by 3-channel ECG digital Holter recorder were examined.

Results

All time and frequency-domain HRV parameters (except LF power) were significantly improved in the exercise groups, compared with the control group (p < 0.05). SDNN, rMSSD, and HF power were boosted, LF power was not different, and the LF/HF ratio decreased after versus before exercise training, independent of exercise modality. HbA1c in aerobic and resistant-training groups, and insulin and LDL in the resistant-training group were decreased after exercise training (p < 0.05).

Conclusions

Exercise training, independent of modality, in patients with type 2 diabetic neuropathy who were clinically free of the cardiovascular disease cause to significant progress in cardiovascular autonomic function assessed by HRV via enhancing cardio-vagal and reducing cardio-sympathetic tone.

Can Exercise Reduce the Autonomic Dysfunction of Patients With Cancer and Its Survivors? A Systematic Review and Meta-Analysis

Background: Cancer therapies have increased patient survival rates, but side effects such as cardiotoxicity and neurotoxicity can lead to autonomic nervous and cardiovascular system dysfunction. This would result in a decrease in parasympathetic activity and the enhancement of sympathetic activity. Heart rate variability (HRV), which reflects autonomic modulation, is a valuable physiological tool since it correlates with cancer-related fatigue, stress, depression, and mortality in patients with cancer.

Objective: This study aimed to analyze the effects of exercise programs on the autonomic modulation, measured by the HRV of patients with cancer and its survivors.

Methods: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed, and the quality of the articles was assessed with the Physiotherapy Evidence Database (PEDro) scale. The meta-analysis statistic procedure was performed by using RevMan software version 5.3.

Results: From the 252 articles found, six studies were included in the review involving 272 participants aged 30–75 years. Exercise programs had a mean length of 10.4 ± 4.6 weeks, a frequency of 3 ± 1.4 days/week, and a mean duration of 78 ± 23.9 min. In time-domain HRV measures, exercise may increase in the SD of normal-to-normal intervals [p < 0.00001, with a mean difference (MD) of 12.79 ms from 9.03 to 16.55] and a decreased root mean square of successive R–R interval differences (p = 0.002, with an MD of 13.08 ms from 4.90 to 21.27) in comparison with control groups (CG). The frequency-domain data reveal that the exercise group (EG) improve significantly more than the CGs in low frequency [absolute power: p < 0.0001, with a standardized mean difference (SMD) of 0.97 from 0.61 to 1.34; relative power: p = 0.04, with an MD = −7.70 from −15.4 to −0.36], high-frequency [absolute power: p = 0.001, with a SMD of 1.49 from 0.32 to 2.66; relative power: p = 0.04, with an MD of 8.00 normalized units (n.u.) from 0.20 to 15.80], and low-to-high frequency ratio (p = 0.007 with an MD of −0.32 from −0.55 to −0.09).

Conclusion: Exercise programs could lead to positive effects on the autonomic modulation of patients with cancer and its survivors. More beneficial changes may occur with resistance and endurance workouts. However, due to the low number of interventions performed, further research is needed to substantiate the findings and to provide additional insights regarding the exercise intensity required to increase the autonomic modulation of the patient.

Mind-Body and Psychosocial Interventions May Similarly Affect Heart Rate Variability Patterns in Cancer Recovery: Implications for a Mechanism of Symptom Improvement

Background:

Advancements in early detection and treatment of cancer have led to increased survival rates and greater need to identify effective supportive care options for resolving symptoms of survivorship. Many non-pharmacological approaches to symptom management during and after cancer treatment involve emotional self-regulation as a central strategy for improving well-being. Identifying commonalities among these strategies’ mechanisms of action may facilitate understanding of what might be useful for optimizing intervention effects. Heart rate variability (HRV) parameters are indicative of improved autonomic nervous system (ANS) balance and resiliency and reduced emotional distress and are thus identified as a mechanism to discuss as a marker of potential for intervention efficacy and a target for optimization.

Methods:

HRV data from 2 studies, 1 examining a mind-body intervention and 1 examining a psychosocial intervention, are presented as a point of discussion about preliminary associations between the interventions, change in HRV, and emotional distress reduction.

Results:

HRV significantly decreased in sympathetic activity in response to a mind-body intervention (Qigong/Tai Chi), and increased vagal tone in response to a psychosocial (storytelling) intervention. In both, these changes in HRV parameters were associated with improved emotional states.

Conclusion:

Our preliminary data suggest that HRV may serve as an important marker of underlying changes that mediate emotional regulation; this observation deserves further investigation. If identified as a worthy target, focusing on interventions that improve HRV within the context of interventions for cancer patients may be important to key outcomes and clinical practice.

Effectiveness of physical activity interventions in improving objective and patient-reported outcomes in head and neck cancer survivors: A systematic review

OBJECTIVE

To assess the effectiveness of physical activity interventions in improving objective and patient-reported outcomes in HNC survivors.

INTRODUCTION

Multiple guidelines recommend that head and neck cancer (HNC) survivors participate in regular physical activity. Physical activity is associated with improved outcomes and mortality in healthy individuals as well as in certain cancer populations. However, the effectiveness of physical activity interventions in HNC survivors is inadequately understood.

METHODS AND RESULTS

Our literature search through December 2018 identified 2,392 articles. After de-duplication, title and abstract review, full-text review and bibliographic search, 20 studies met all inclusion criteria. Inclusion criteria included any full-body physical activity intervention in HNC survivors that did not target discrete organ sites or functions (e.g. swallowing). Study cohorts included 749 predominantly male participants with a mean age range of 48-63 years. At their conclusion, physical activity interventions were associated with at least one significant improvement in an objective or patient-reported outcome in 75% of studies. Aerobic capacity and fatigue were the most commonly improved outcomes. None of the included studies evaluated associations with survival or recurrence. Although traditional aerobic and resistance interventions were more common, a greater proportion of alternative physical activity (yoga and Tai Chi) interventions demonstrated improved objective and patient-reported outcomes.

CONCLUSION

Physical activity interventions in HNC survivors often conferred some improvement in objective and patient-reported outcomes. Additional highly-powered, randomized controlled studies are needed to establish the optimal type, intensity, and timing of physical activity interventions as well as their impact on oncologic outcomes.

The Health Promoting Mindfulness or Qigong Educational Programs for Beneficial Lifestyle Changes of Cancer Survivors

This study used heart rate variability (HRV) to monitor levels of cancer-related fatigue (CRF) and quality of life (QOL) of cancer survivors subjected to program measures at different psychosomatic or functional levels. A longitudinal study was conducted at a cancer center in Taiwan. Fifty-two cancer survivals were randomly assigned to either the mindfulness group (n = 25) or the Qigong group (n = 27). Both groups received a 12-week mindfulness and Qigong programs, respectively. Improvements in CRF, QOL, and HRV after a 12-week program and at the 3-month follow-up point. For the long-term effects in both mindfulness and Qigong groups, CRF showed a significant downward trend (p < 0.05), but a significant upward trend was observed in HRV (p < 0.001). Mindfulness and Qigong exhibited different effectiveness in individuals, indicating that the mental and physical aspects of health are equally essential and should be addressed in a complementary combination. These findings are worthy of being shared with cancer survivors to benefit their physical and mental well-being. We suggest that healthcare professionals incorporate mindfulness and Qigong in cancer survivors' daily life as means to encourage lifestyle changes for improving their health.

Spectral analysis of heart rate variability for trauma outcome prediction: an analysis of 210 ICU multiple trauma patients

PURPOSE

This study aimed to test and compare short-term spectral HRV indices with most used trauma scorings in outcome prediction of multiple trauma, and then to explore the efficacy of their combined application.

METHODS

A prospective study was conducted for patients with blunt multiple trauma admitted to an emergency intensive care unit (ICU) between January 2016 and December 2017. Short-term spectral HRV indices on admission were measured, including normalized low-frequency power (nLF), normalized high-frequency power (nHF), and the nLF/nHF ratio. Injury severity score (ISS), new injury severity score (NISS), and revised trauma score (RTS) were evaluated for each patient, as well as probability of survival (Ps) by trauma and injury severity score (TRISS) model. The primary outcome was 30-day mortality and secondary outcomes were incidence of multiple organ dysfunction syndrome (MODS) and length of ICU stay.

RESULTS

Two hundred and ten patients were recruited. The nLF/nHF ratio, RTS, and Ps_(TRISS) were independent predictors of 30-day mortality, while nLF/nHF, NISS and RTS were independent predictors of MODS. The area under the receiver operating characteristic (ROC) curve (AUC) of nLF/nHF for 30-day mortality prediction was 0.924, comparable to RTS (0.951) and Ps_(TRISS) (0.892). AUC of nLF/nHF-RTS combination was 0.979, significantly greater than that of each alone. Combination of nLF/nHF and Ps_(TRISS) showed an increased AUC (0.984) compared to each of them. The nLF/nHF ratio presented a similar AUC (0.826) to NISS (0.818) or RTS (0.850) for MODS prediction. AUC of nLF/nHF-RTS combination was 0.884, significantly greater than that of nLF/nHF. Combination of nLF/nHF and NISS showed a greater AUC (0.868) than each alone. The nLF/nHF ratio, NISS, RTS, and Ps_(TRISS) were correlated with length of ICU stay for survivors, with correlation coefficients 0.476, 0.617, - 0.588, and - 0.539.

CONCLUSIONS

These findings suggest that the short-term spectral analysis of HRV might be a potential early tool to assess injury severity and predict outcome of multiple trauma. Combination of nLF/nHF and conventional trauma scores can provide more accuracy in outcome prediction of multiple trauma.

Impact of supportive therapy modalities on heart rate variability in cancer patients - a systematic review

Purpose: To systematically review literature for interventional studies and their impact on autonomic dysfunction assessed by heart rate variability in cancer patients.Methods: Research was conducted using the databases Medline/Pubmed, Scopus, and Web of science from their inception to October 2017. Original articles with an interventional design that reported changes in at least one heart rate variability parameter as outcome parameter were included and described.Results: Ten studies were identified as eligible for subsequent analysis. The main application field in oncological therapy setting was music therapy intervention, Traditional Chinese Medicine related treatments, exercise interventions, relaxation, and myofascial release techniques. Breast cancer was the most frequently described single cancer entity. Heart rate variability recording was performed with standard electrocardiography devices or wearable heart rate monitors, within a time range between 5 and 20 min and a sampling rate varying from 200 to 1000 Hz. No adverse events were reported in all studies.Conclusions: Supportive therapy modalities may have the potential to enhance vegetative functioning. In this context, heart rate variability analysis appears to be an easily applicable and safe method to evaluate cancer related autonomic dysfunction. More large prospective multicentre randomised controlled trials are needed.Implication for rehabilitationMost cancer patients face autonomic dysfunction due to the disease itself the applied treatments or combination of both.HRV measurement is an easy and safe method to asses autonomic dysfunction.Supportive treatments targeting on an elevation of the vagal tone and autonomic balance in general might have beneficial effects for cancer patients.

Promoting Physical and Psychological Rehabilitation Activities and Evaluating Potential Links Among Cancer-Related Fatigue, Fear of Recurrence, Quality of Life, and Physiological Indicators in Cancer Survivors

Objectives: Cancer-related fatigue and fear of recurrence (FOR) are the most common symptoms in cancer survivors and severely affect quality of life (QOL). This study aims to promote and evaluate the effectiveness of physical and psychological rehabilitation activities for cancer survivors. Methods: A longitudinal study with an interventional research design was conducted. A total of 80 participants were randomly assigned to experimental groups E1 (Qigong exercise [QE]) or E2 (stress management [SM]) or the control group. The E1 and E2 groups received QE and SM, respectively, as interventions once a week for 12 weeks, and effects were assessed. Cancer-related fatigue, FOR, QOL, and heart rate variability (HRV) were evaluated at baseline (T0), after 12 weeks (T1), and at the 3-month follow-up (T2). Results: QE and SM effectively strengthened the physical and psychological functions of cancer survivors at the T1 phase. Although differences in FOR and QOL were not statistically significant, the scores were decreased and increased, respectively. Although the effects during the T2 phase were not as significant as those during T1, the score progress was maintained. The effects on HRV were significantly different among the E1, E2, and control groups at T1, which shows that the performance of both experimental groups was better than that of the control group. Conclusions: Physical and psychological rehabilitation activities should be practiced periodically and should be led by professional staff. Long-term educational resources and care should also be provided. HRV can be used to efficiently monitor the status of the mind-body balance and is a more suitable index than questionnaires for physical and psychological function evaluation in cancer survivors.

Acute Physiological and Psychological Effects of Qigong Exercise in Older Practitioners

Qigong is a gentle exercise that promotes health and well-being. This study evaluated the acute physiological and psychological effects of one session of qigong exercise in older practitioners. A total of 45 participants (mean age, 65.14 years) were recruited. Meridian electrical conductance, State-Trait Anxiety Inventory (STAI), heart rate variability (HRV), and Short Form 36 (SF-36) were evaluated and compared before and after one session of qigong exercise. The results revealed that the electrical conductance of all meridians, except spleen and bladder meridians, increased significantly (p < 0.05). Compared with baseline values, upper to lower body ratio and sympathetic/vagal index were significantly improved and closer to 1 (p = 0.011 and p = 0.007, resp.). STAI-S and STAI-T scores decreased significantly (p < 0.001 and p = 0.001, resp.). The RR interval of HRV decreased significantly (p = 0.035), a significant positive correlation was observed between kidney meridian electrical conductance and SF-36 physical scores (r = 0.74, p = 0.018), and a positive correlation was observed between pericardium meridian electrical conductance and SF-36 mental scores (r = 0.50, p = 0.06). In conclusion, one session of qigong exercise increased meridian electrical conductance, reduced anxiety, and improved body and autonomic nervous system balance. These findings provide scientific evidence for acute physiological and psychological effects of qigong exercise in older practitioners.

Loneliness, Social Isolation, and Cardiovascular Health

SIGNIFICANCE

Social and demographic changes have led to an increased prevalence of loneliness and social isolation in modern society. Recent Advances: Population-based studies have demonstrated that both objective social isolation and the perception of social isolation (loneliness) are correlated with a higher risk of mortality and that both are clearly risk factors for cardiovascular disease (CVD). Lonely individuals have increased peripheral vascular resistance and elevated blood pressure. Socially isolated animals develop more atherosclerosis than those housed in groups.

CRITICAL ISSUES

Molecular mechanisms responsible for the increased cardiovascular risk are poorly understood. In recent reports, loneliness and social stress were associated with activation of the hypothalamic-pituitary-adrenocortical axis and the sympathetic nervous system. Repeated and chronic social stress leads to glucocorticoid resistance, enhanced myelopoiesis, upregulated proinflammatory gene expression, and oxidative stress. However, the causal role of these mechanisms in the development of loneliness-associated CVD remains unclear.

FUTURE DIRECTIONS

Elucidation of the molecular mechanisms of how CVD is induced by loneliness and social isolation requires additional studies. Understanding of the pathomechanisms is essential for the development of therapeutic strategies to prevent the detrimental effects of social stress on health. Antioxid. Redox Signal. 28, 837-851.

Effects of Tai Chi Exercise on Cancer-Related Fatigue in Patients With Nasopharyngeal Carcinoma Undergoing Chemoradiotherapy: A Randomized Controlled Trial

CONTEXT

Tai Chi exercise has been shown to improve cancer-related fatigue (CRF) and autonomic nervous system (ANS) balance in some cancer patients or survivors; however, such effects are yet to be verified in nasopharyngeal carcinoma (NPC) patients undergoing chemoradiotherapy.

OBJECTIVES

To explore the effects of Tai Chi exercise on CRF in NPC patients undergoing chemoradiotherapy and then to evaluate ANS information indicated by heart rate variability parameters and their association with CRF.

METHODS

A randomized controlled trial of Tai Chi exercise was conducted from January 2014 to August 2015. Participants in the Tai Chi group practiced Tai Chi a one-hour session, five sessions/week during chemoradiotherapy. Participants in the control group received usual care. The primary end points were scores of the multidimensional fatigue symptom inventory-short form (MFSI-SF). Secondary end points were heart rate variability parameters, including normalized low-frequency (nLF) power, normalized high-frequency (nHF) power, and the nLF/nHF ratio, and their association with CRF.

RESULTS

One hundred fourteen patients were recruited in this study, and 83 patients completed the trial. The Tai Chi group and the control group had comparable baseline characteristics. After chemoradiotherapy, the Tai Chi group exhibited lower MFSI-SF total score and three negative subscale (general, physical, and emotional fatigue) scores and higher vigor score compared with the control group (P < 0.01 for all). The nLF/nHF ratio was significantly lower in the Tai Chi group compared to the control group after chemoradiotherapy. The MFSI-SF total score was markedly correlated with the nLF/nHF ratio.

CONCLUSION

Tai Chi exercise is conducive to alleviate CRF in NPC patients undergoing chemoradiotherapy. The improvement in ANS balance might fit into the process of Tai Chi for CRF management in this population.

Heart Rate Variability as a Marker of Distress and Recovery: The Effect of Brief Supportive Expressive Group Therapy With Mindfulness in Cancer Patients

Objectives. We aimed to investigate the effects of brief supportive expressive group therapy with mindfulness for cancer patients and to assess the utility of heart rate variability (HRV) as a biomarker of distress and treatment effect. Methods. A total of 28 female patients with nonmetastatic cancer at a university hospital in South Korea received a 4-week modified group therapy for distress reduction. The BESTMIND (Brief Expression and Support Therapy with Mindfulness) program consisted of supportive–expressive group therapy and mindfulness-based stress reduction. The subjective outcomes of distress, anger, sleep quality, and sense of well-being and the physiological outcome of HRV were assessed before and after the program. Results. After the program, patients showed significantly reduced distress, perceived stress, anger, and sleep disturbance and increased quality of life. No significant change was observed in the degree of mindfulness. A significantly increased SD in the normal beat-to-beat intervals and normalized high-frequency (HF 0.15-0.4 Hz) power from spectral analysis were observed after treatment. According to the correlation analyses, HF power correlated with depression scores, and normalized HF power was associated with depression, anxiety, perceived stress, and anger at baseline. The pretreatment and posttreatment comparison indicated that an increase in HF power was associated with a decrease in anger. Conclusions. These results suggest the effectiveness of this modified group-based program for distress reduction and also provide preliminary evidence for the use of HRV as a biomarker of distress and recovery. HF power from HRV variables may serve as a quantitative biomarker of the treatment response of distress management, including anger.

Qigong and Tai-Chi for Mood Regulation

Qigong and Tai-Chi are traditional self-healing, self-cultivation exercises originating in ancient China. These exercises are characterized by coordinated body posture and movements, deep rhythmic breathing, meditation, and mental focus based on traditional Chinese medicine theories. Although the exact mechanisms of Qigong's and Tai-Chi's effects on physical and mental well-being are unknown, these practices may be viewed as meditative movements and share many of the healing elements observed in mindfulness meditation. Clinical studies including randomized controlled trials and meta-analyses have shown that both Qigong and Tai-Chi have beneficial effects on psychological well-being and reduce symptoms of anxiety and depression. Qigong and Tai-Chi frequently involve anchoring attention to interoceptive sensations related to breath or other parts of the body, which has been shown to enhance nonreactivity to aversive thoughts and impulses. Preliminary studies suggest that the slow movements in Qigong and Tai-Chi with slowing of breath frequency could alter the autonomic system and restore homeostasis, attenuating stress related to hypothalamus-pituitary-adrenal axis reactivity and modulating the balance of the autonomic nervous system toward parasympathetic dominance. Qigong's and Tai-Chi's effects on emotion regulation could occur through changes in multiple prefrontal regions, the limbic system, and the striatum or in the expression of genes linked to inflammatory responses and stress-related pathways.

Physical Exercise Improves Heart Rate Variability in Patients with Type 2 Diabetes: A Systematic Review

PURPOSE OF REVIEW

The aim of the present systematic review is to provide an up-to-date analysis of the research on the effects of exercise programs on heart rate variability (HRV) in individuals with type 2 diabetes mellitus (T2DM). An electronic search of the literature (PubMed, PEDro and Web of Science) was performed. "HRV", "heart rate variability", "exercise", "physical" and "diabetes" were the terms used for article retrieval. Lastly, 15 articles were selected. PRISMA methodology was employed and data were extracted according to the PICOS approach.

RECENT FINDINGS

Although HRV is not routinely measured in the management of T2DM, it is an important measure due to its relation with mortality and diabetic neuropathy. Physical exercise has become a therapy for T2DM, because it improves physical fitness and functional capacity, enhances metabolic control and insulin sensitivity, reduces inflammatory markers and neuropathy symptoms and can increase the regenerative capacity of cutaneous axons, slowing or preventing neuropathy progression. However, it is not clear to what extent physical exercise can improve HRV in this population. Participation in the 15 selected studies was similar in men and women (48.01% men and 51.99% women). All the intervention programs included aerobic training, and it was complemented by strength training in four studies. Duration of physical exercise sessions ranged between 30 and 75 min, the frequency being between 2 and 7 days/week. Statistically significant improvements in groups with diabetes, relative to baseline, were observed in nine studies. More than 3 days per week of aerobic training, complemented by strength training, during at least 3 months seems to improve HRV in T2DM. Weekly frequency might be the most important factor to improve HRV. These aspects could help to design better programs based in scientific evidence, incorporating HRV as an important variable associated with diabetic neuropathy and mortality.

Impact of personality-oriented programs of physical rehabilitation on the heart rate variability in women with post-mastectomy syndrome

Introduction. The aim of the study was to determine the effect of personality-oriented physical rehabilitation programs on the heart rate variability in women with post-mastectomy syndrome. Methods. The following methods were applied: theoretical analysis of scientific and methodologic literature data, heart rate variability analysis, and mathematical statistical methods. The subjects of the study were 50 women with late symptoms of post-mastectomy syndrome. The study was conducted during the ambulatory rehabilitation stage after Madden radical mastectomy. All the indicators of the heart rate variability were equivalent in the main and comparison groups at the beginning of rehabilitation. The impact of training was examined every 6 months over the course of a year. Results. Measurements were taken three times: at the beginning of rehabilitation and after 6 and 12 months. It was found that most of the investigated parameters of heart rate variability in both groups steadily improved during the year of rehabilitation. The average values of stress index and amplitude of mode after 12 months of rehabilitation were lower in the main group than in the comparison group but the values of the standard deviation of normal-to-normal intervals and the very low-frequency component of the spectrum were better by 6.48 ms (p < 0.05) and 203.29 ms2 (p < 0.05), respectively. Conclusions. The personality-oriented programs of physical rehabilitation were effective in augmenting heart rate variability and restoring autonomic balance in patients with post-mastectomy syndrome.

Effects of circuit exercise on autonomic nerve system of survivors after surgery of breast cancer

[Purpose] This study aimed to investigate the effects of exercise on the autonomic nervous system of breast cancer survivors by measuring heart rate variability during an 8-week circulation exercise program. [Subjects and Methods] This intervention study included 22 volunteer female participants, younger than 65 years, who were selected from patients who had been diagnosed with carcinoma in situ and primary invasive breast cancer, stage I-III, in accordance with the American Joint Committee on Cancer (2009) and had undergone breast surgery. [Results] Despite the statistically significant differences in the low-frequency range (log), the high-frequency range (log), the standard deviation of the N-N interval, and the root mean square of differences values, which are heart rate variability indicators after exercise, between the two groups, no statistically significant difference was found in the low-frequency range/the high-frequency range values between the two groups. [Conclusion] The improvement in heart rate variability during the 8-week circulation exercise program confirms the increase in the activity of the autonomic nervous system of breast cancer patients after surgery.