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

Effect of exercise training on cardiac autonomic function in type 2 diabetes mellitus: a systematic review and meta-analysis

BACKGROUND

Cardiac autonomic neuropathy (CAN) is an underdiagnosed complication of type 2 diabetes mellitus (T2DM) and is associated with cardiovascular morbidity and mortality. Cardiac autonomic reflex tests (CARTs) are the gold standard; they are non-invasive and clinically feasible for screening CAN. The objective of the present meta-analysis was to examine exercise's effect on cardiac autonomic function using CARTs in T2DM.

METHODS

The Preferred Reporting Items for Systematic Review and Meta-Analysis Checklist (PRISMA) was used. Electronic databases were systematically used to retrieve relevant studies after title and abstract screening. Studies utilizing exercise training with cardiac autonomic function (CARTs) outcomes in individuals with type 2 diabetes mellitus were included. The meta-analysis was conducted using RevMan 5.4.1, using the random effects model, and appropriate tests for heterogeneity. The Cohrane ROB-2 tool was used for randomized controlled trials (RCTs) and the ROBINS-I tool for non-RCT for risk of bias assessment were used.

RESULTS

Three studies were included (two for meta-analysis), considering the outcome of the E:I ratio, 30:15 ratio, and Valsalva ratio. The studies did not show any influence on the E:I and 30:15 ratio in the pooled analysis with a low risk of ineffectiveness for the exercise intervention. Exercise training significantly affected the Valsalva ratio. A different type of exercise intervention was utilized in all three studies. There was a low to moderate certainty for the evidence.

CONCLUSION

The results indicate that further robust and high-quality randomized controlled trials utilizing cardiac autonomic reflex tests (which have clinical and physiological relevance) in type 2 diabetes mellitus are required for drawing conclusions.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42023445561.

Cardiorespiratory fitness, atrial fibrillation and stroke: a review of the evidence in 2024

INTRODUCTION

The body of evidence linking cardiorespiratory fitness (CRF) levels with the risk of atrial fibrillation (AF) and stroke - two interconnected cardiovascular conditions - is not entirely consistent. Furthermore, specific CRF thresholds beyond which the risk of AF or stroke might not decrease are not well defined.

AREAS COVERED

This review summarizes research evidence on the role of CRF in the development of AF and stroke including dose-response relationships in general population participants, explores the biological mechanisms through which CRF may exert its effects, assesses the potential implications for clinical care and population health, identifies gaps in the current evidence, and suggest directions for future research. MEDLINE and Embase were searched from inception until July 2024 to identify observational longitudinal and interventional studies as well as systematic reviews and meta-analyses related to these study designs.

EXPERT OPINION

In the general population, increasing levels of CRF, achieved through consistent physical activity, can significantly reduce the likelihood of developing AF and stroke. The findings also advocate for a tailored approach to exercise prescriptions, acknowledging the plateau in benefits for AF risk beyond certain CRF levels, while advocating for higher intensity or prolonged activity to further reduce stroke risk.

Physical exercise as treatment for adults with type 2 diabetes: a rapid review

Background

Type 2 diabetes mellitus (T2DM) is a leading cause of disability-adjusted life years (DALY). Physical exercise is an effective non-pharmacological intervention to promote glycaemic control in T2DM. However, the optimal exercise parameters for glycemic control in individuals with T2DM remain unclear.

Objective

This study aimed to analyze the relationship between physical training variables - frequency, intensity, type, duration, volume, and progression - and glycemic control in individuals with T2DM.

Methods

A rapid systematic literature review was conducted on PubMed and LILACS databases. The PICOT strategy was employed to define the inclusion criteria. Eligible studies had to assess the impact of exercise parameters (frequency, intensity, type, duration, volume, and progression) on glycemic control indicators, primarily glycosylated hemoglobin (HbA1c). Randomized and non-randomized clinical trials were included in the review. The methodological quality of each study was assessed using the PEDro scale (PROSPERO - CRD 42021262614).

Results

Out of 1188 papers initially identified, 18 reports met the inclusion criteria and were included in the analysis. A total of 1,228 participants with T2DM (1086 in exercise groups) were included in the selected studies. Among these studies, 16 (88.9%) were RCTs and 2 (11.1%) were nRCTs. The age of participants ranged from 43.1 and 68.9 years, and the average intervention duration was 16.8 weeks. Data on adherence to the intervention, adverse events, detailed intervention protocol, and its impacts on glycaemic control, lipid profile, blood pressure, anthropometric measures, medication, body composition, and physical fitness are reported.

Conclusion

The evidence supports the safety and effectiveness of physical exercises as non-pharmacological interventions for glycemic control. Aerobic, resistance and combined training interventions were associated with reductions in HbA1c and fasting glucose. The diversity of the physical exercise intervention protocols investigated in the studies included in this review is an important limitation to generalizing evidence-based practice. The call for action is mandatory to implement large-scale education programs on the prevention of diabetes and public health policies aimed to include well-planned and supervised exercise programs as an essential part of the primary prevention of type 2 diabetes.

Systematic Review Registration

PROSPERO, identifier (CRD42021262614).

Theoretical Derivation of a Telephone-Based Health Coaching Intervention for Promoting Physical Activity and Healthy Nutrition

Present research regarding interventions to change behavior suffers from insufficient communication of their theoretical derivation. This insufficient communication is caused by the restrictions imposed by most of the relevant scientific journals. This impedes further intervention development. In this article, a telephone-based health coaching (TBHC) intervention is introduced using a format outside these restrictions. This intervention is seen as a combination of (1) the activities performed with the target persons, i.e., its core, and (2) measures to ensure the quality of the intervention. The theoretical derivation of the core is presented. The core is seen to consist of (1) the style of coach-patient interaction and (2) the contents of this interaction. The style of coach-patient interaction was derived from self-determination theory and was concretized using motivational interviewing techniques. The contents of the coach-patient interaction were derived from the health action process approach and were concretized using behavior-change techniques. The derivation led to (1) a set of 16 coaching tools referring to the different states in which a patient might be and containing state-specific recommendations for performing the coaching session, and (2) guidelines for selecting the appropriate coaching tool for each session. To ensure the quality of the intervention, a coach-training program before and supervision sessions during the TBHC were added.

A Nonrandomized Trial of the Effects of Passive Simulated Jogging on Short-Term Heart Rate Variability in Type 2 Diabetic Subjects

Background

Diabetes mellitus has reached global epidemic proportions, with type 2 diabetes (T2DM) comprising more than 90% of all subjects with diabetes. Cardiovascular autonomic neuropathy (CAN) frequently occurs in T2DM. Heart rate variability (HRV) reflects a neural balance between the sympathetic and parasympathetic autonomic nervous systems (ANS) and a marker of CAN. Reduced HRV has been shown in T2DM and improved by physical activity and exercise. External addition of pulses to the circulation, as accomplished by a passive simulated jogging device (JD), restores HRV in nondiseased sedentary subjects after a single session. We hypothesized that application of JD for a longer period (7 days) might improve HRV in T2DM participants.

Methods

We performed a nonrandomized study on ten T2DM subjects (age range 44-73 yrs) who were recruited and asked to use a physical activity intervention, a passive simulated jogging device (JD) for 7 days. JD moves the feet in a repetitive and alternating manner; the upward movement of the pedal is followed by a downward movement of the forefoot tapping against a semirigid bumper to simulate the tapping of feet against the ground during jogging. Heart rate variability (HRV) analysis was performed using an electrocardiogram in each subject in seated posture on day 1 (baseline, BL), after seven days of JD (JD7), and seven days after discontinuation of JD (Post-JD). Time domain variables were computed, viz., standard deviation of all normal RR intervals (SDNN), standard deviation of the delta of all RR intervals (SDΔNN), and the square root of the mean of the sum of the squares of differences between adjacent RR intervals (RMSSD). Frequency domain measures were determined using a standard Fast Fourier spectral analysis, as well as the parameters of the Poincaré plots (SD1 and SD2).

Results

Seven days of JD significantly increased SDNN, SDΔNN, RMSSD, and both SD1 and SD2 from baseline values. The latter parameters remained increased Post-JD. JD did not modify the frequency domain measures of HRV.

Conclusion

A passive simulated jogging device increased the time domain and Poincaré variables of HRV in T2DM. This intervention provided effortless physical activity as a novel method to harness the beneficial effects of passive physical activity for improving HRV in T2DM subjects.

Blood hemoglobin A1c might predict adverse differences in heart rate variability in a diabetic population: Evidence from the Midlife in the United States (MIDUS) study

Background

Cardiac autonomic neuropathy in population with diabetes mellitus (DM) is frequent and linked with high risk of cardiovascular mortality. However, studies on whether blood hemoglobin A1c (HbA1c) levels are related to adverse differences in heart rate variability (HRV) in individuals with DM are scarce.

Aim

We aimed to investigate the association of blood HbA1c levels with adverse differences in HRV, which is an indicator of cardiac autonomic control, in adult individuals with and without DM.

Methods

Data were collected from the Midlife in the United States (MIDUS) study, and 928 individuals were analyzed for the relationship between blood HbA1c levels and HRV through a cross-sectional analysis.

Results

Participants with DM had significantly higher HRV than those without DM. The smooth curve suggested inverse relationships between blood HbA1c levels and HF- and LF-HRV seen in participants with DM but not in those without DM after controlling for all covariates (age, sex, BMI, smoking, number of drinking years and exercise). Furthermore, linear regression analysis demonstrated that elevated blood HbA1c levels did contribute to adverse differences in HF-HRV (Sβ= -0.118; 95% CI -0.208, -0.027; P=0.012) and LF-HRV (Sβ= -0.097; 95% CI -0.177, -0.017; P=0.019) after controlling for these covariates in participants with DM, while in participants without DM, blood HbA1c was not significantly related to adverse differences in HF-HRV (Sβ=0.095; 95% CI -0.059, 0.248; P=0.228) or LF-HRV (Sβ=0.043; 95% CI -0.103, 0.189; P=0.565). DM has a significant modifying effect on associations between blood HbA1c and adverse differences in HF-HRV (P for interaction=0.019) and LF-HRV (P for interaction=0.029).

Conclusions

We reported strong evidence that elevated blood levels of HbA1c were associated with adverse differences in HRV in the diabetic population but not in the nondiabetic population. This finding supported that long-term hyperglycemia is related to autonomic nerve injury in the diabetic population. Blood HbA1c might be a good indicator of cardiac autonomic neuropathy.

Exercise, Physical Activity, and Cardiometabolic Health: Insights into the Prevention and Treatment of Cardiometabolic Diseases

Physical activity (PA) and exercise are widely recognized as essential components of primary and secondary cardiovascular disease (CVD) prevention efforts and are emphasized in the health promotion guidelines of numerous professional societies and committees. The protean benefits of PA and exercise extend across the spectrum of CVD, and include the improvement and reduction of risk factors and events for atherosclerotic CVD (ASCVD), cardiometabolic disease, heart failure, and atrial fibrillation (AF), respectively. Here, we highlight recent insights into the salutary effects of PA and exercise on the primary and secondary prevention of ASCVD, including their beneficial effects on both traditional and nontraditional risk mediators; exercise "prescriptions" for ASCVD; the role of PA regular exercise in the prevention and treatment of heart failure; and the relationships between, PA, exercise, and AF. While our understanding of the relationship between exercise and CVD has evolved considerably, several key questions remain including the association between extreme volumes of exercise and subclinical ASCVD and its risk; high-intensity exercise and resistance (strength) training as complementary modalities to continuous aerobic exercise; and dose- and intensity-dependent associations between exercise and AF. Recent advances in molecular profiling technologies (ie, genomics, transcriptomics, proteomics, and metabolomics) have begun to shed light on interindividual variation in cardiometabolic responses to PA and exercise and may provide new opportunities for clinical prediction in addition to mechanistic insights.

High-intensity interval training for 12 weeks improves cardiovascular autonomic function but not somatosensory nerve function and structure in overweight men with type 2 diabetes

AIMS/HYPOTHESIS

It remains unclear whether and which modality of exercise training as a component of lifestyle intervention may exert favourable effects on somatosensory and autonomic nerve tests in people with type 2 diabetes.

METHODS

Cardiovascular autonomic and somatosensory nerve function as well as intraepidermal nerve fibre density (IENFD) were assessed in overweight men with type 2 diabetes (type 2 diabetes, n = 20) and male glucose-tolerant individuals (normal glucose tolerance [NGT], n = 23), comparable in age and BMI and serving as a control group, before and after a supervised high-intensity interval training (HIIT) intervention programme over 12 weeks. Study endpoints included clinical scores, nerve conduction studies, quantitative sensory testing, IENFD, heart rate variability, postural change in systolic blood pressure and spontaneous baroreflex sensitivity (BRS).

RESULTS

After 12 weeks of HIIT, resting heart rate decreased in both groups ([mean ± SD] baseline/12 weeks: NGT: 65.1 ± 8.2/60.2 ± 9.0 beats per min; type 2 diabetes: 68.8 ± 10.1/63.4 ± 7.8 beats per min), while three BRS indices increased (sequence analysis BRS: 8.82 ± 4.89/14.6 ± 11.7 ms²/mmHg; positive sequences BRS: 7.19 ± 5.43/15.4 ± 15.9 ms²/mmHg; negative sequences BRS: 12.8 ± 5.4/14.6 ± 8.7 ms²/mmHg) and postural change in systolic blood pressure decreased (-13.9 ± 11.6/-9.35 ± 9.76 mmHg) in participants with type 2 diabetes, and two heart rate variability indices increased in the NGT group (standard deviation of R-R intervals: 36.1 ± 11.8/55.3 ± 41.3 ms; coefficient of R-R interval variation: 3.84 ± 1.21/5.17 ± 3.28) (all p<0.05). In contrast, BMI, clinical scores, nerve conduction studies, quantitative sensory testing, IENFD and the prevalence rates of diabetic sensorimotor polyneuropathy and cardiovascular autonomic neuropathy remained unchanged in both groups. In the entire cohort, correlations between the changes in two BRS indices and changes in [Formula: see text] over 12 weeks of HIIT (e.g. sequence analysis BRS: r = 0.528, p=0.017) were observed.

CONCLUSIONS/INTERPRETATION

In male overweight individuals with type 2 diabetes, BRS, resting heart rate and orthostatic blood pressure regulation improved in the absence of weight loss after 12 weeks of supervised HIIT. Since no favourable effects on somatic nerve function and structure were observed, cardiovascular autonomic function appears to be more amenable to this short-term intervention, possibly due to improved cardiorespiratory fitness.

The cholinergic anti-inflammatory pathway in humans: State-of-the-art review and future directions

The parasympathetic nervous system modulates inflammation through efferent vagus nerve signaling. Tracey (2002) termed this process as the cholinergic anti-inflammatory pathway (CAP). Interest in the potential practical use of this immune-modulatory process is increasing alongside increasing appreciation for the role of systemic inflammation in the etiology of somatic and psychological disease. A diverse literature exists providing expansive correlational evidence and some preliminary experimental evidence of the CAP in humans. However, so far this literature has not been well integrated and critically evaluated. This review describes the current state-of-the-art of research into vagus nerve driven parasympathetic control of inflammation in humans. Substantial limitations and gaps in the literature are identified, and promising directions for future research are highlighted.

Cardiac Autonomic Modulation and Response to Sub-Maximal Exercise in Chilean Hypertensive Miners

Cardiac autonomic modulation in workers exposed to chronic intermittent hypoxia (CIH) has been poorly studied, especially considering hypertensive ones. Heart rate variability (HRV) has been proven as valuable tool to assess cardiac autonomic modulation under different conditions. The aim of this study is to investigate the cardiac autonomic response related to submaximal exercise (i.e., six-minute walk test, 6MWT) in hypertensive (HT, n = 9) and non-hypertensive (NT, n = 10) workers exposed for > 2 years to CIH. Participants worked on 7-on 7-off days shift between high altitude (HA: > 4.200 m asl) and sea level (SL: < 500 m asl). Data were recorded with electrocardiography (ECG) at morning upon awakening (10 min supine, baseline), then at rest before and after (5 min sitting, pre and post) the 6MWT, performed respectively on the first day of their work shift at HA, and after the second day of SL sojourn. Heart rate was higher at HA in both groups for each measurement (p < 0.01). Parasympathetic indices of HRV were lower in both groups at HA, either in time domain (RMSSD, p < 0.01) and in frequency domain (log HF, p < 0.01), independently from measurement's time. HRV indices in non-linear domain supported the decrease of vagal tone at HA and showed a reduced signal's complexity. ECG derived respiration frequency (EDR) was higher at HA in both groups (p < 0.01) with interaction group x altitude (p = 0.012), i.e., higher EDR in HT with respect to NT. No significant difference was found in 6MWT distance regarding altitude for both groups, whereas HT covered a shorter 6MWT distance compared to NT (p < 0.05), both at HA and SL. Besides, conventional arm-cuff blood pressure and oxygen blood saturation values (recorded before, at the end and after 5-min recovery from 6MWT), reported differences related to HA only. HA is the main factor affecting cardiac autonomic modulation, independently from hypertension. However, presence of hypertension was associated with a reduced physical performance independently from altitude, and with higher respiratory frequency at HA.

Respiratory Sinus Arrhythmia as a Physiological Resilience Marker for Children's Health

OBJECTIVE

The current study aimed to test parasympathetic nervous system activity, indexed through resting respiratory sinus arrhythmia (RSA) as a resilience factor that moderates the associations between socioeconomic status (SES), circulating cytokines, and somatic health in children.

METHODS

The sample included 181 parent-child dyads (mean [standard deviation] child age = 9.91 [0.57] years; 50.3% boys). Parents reported on family income, parental education, and subjective social status, to index SES. Children provided serum samples for assaying circulating inflammatory cytokines and had RSA measured during a 5-minute seated resting period. We used a composite measure of inflammation that combined standardized measures of interleukin 6, interleukin 10, and tumor necrosis factor α. Parents reported on their child's global health impairment and number of chronic health conditions.

RESULTS

Lower SES was associated with poorer global health, and higher levels of inflammation were associated with poorer global health, but these associations were not significant among children with high resting RSA. Specifically, resting RSA moderated the association between SES and global health impairment (B = 0.09, standard error [SE] = 0.02, p < .001). Preliminary evidence suggests that resting RSA may also moderate the association between inflammation and global health impairment (B = -0.12, SE = 0.03, p < .001), although this effect was no longer significant after Winsorizing an outlier value of a child with high global health impairment (B = -0.06, SE = 0.03, p = .04).

CONCLUSIONS

High resting RSA may represent a physiological profile of resilience in children, weakening the associations between low SES and poor somatic health, and between greater inflammation and poor somatic health.

Prevention of Peripheral Distal Polyneuropathy in Patients with Diabetes: A Systematic Review

Background: Diabetic peripheral neuropathy (DPN) is the most frequent chronic complication and is that which generates the highest disability and mortality in diabetes mellitus (DM). As it is currently the only microvascular complication of DM without a specific treatment, prevention is essential. The aim of this study was to determine the most effective preventive strategy to avoid or delay the appearance and/or development of DPN in patients with DM. Methods: A systematic search was carried out in the main health science databases (PubMed, Scopus, CINAHL, PEDro and The Cochrane Library) from 1 January 2010 to 31 August 2020. The study selection was conducted by two independent reviewers and data extraction was performed by the author. The eligibility criteria included randomized clinical trials (RCTs) and cohort studies from RCTs. Results: Eleven studies were selected that included 23,595 participants with DM. The interventions evaluated were intensive or standard glycemic control, the use of drugs to achieve glycemic control, and the promotion of a healthy lifestyle and exercise. Intensive glucose control achieved a significant reduction in the development of DPN in TIDM patients, and lifestyle modifications and exercise achieved it moderately in TIIDM patients. Conclusions: The main preventive strategy for DPN is intensive glycemic control with a target HbA1c < 6% in patients with TIDM and standard control of 7.0−7.9 in patients with TIIDM, incorporating lifestyle modifications.

Cardiovascular autonomic modulation differences between moderate-intensity continuous and high-intensity interval aerobic training in women with PCOS: A randomized trial

BACKGROUND

Moderate-intensity continuous training (MICT) is strongly recommended for polycystic ovarian syndrome (PCOS) treatment. However, recent studies have suggested that high-intensity interval training (HIIT) would promote great benefits for cardiac autonomic control. Therefore, we investigated whether the benefits of HIIT related to cardiovascular autonomic control were greater than those of MICT in women with PCOS.

METHODS

Women with PCOS were randomly allocated through a blind draw into three groups: control, MICT, and HIIT. The control group did not undergo exercise, whereas those in the MICT and HIIT groups underwent 16 weeks of aerobic physical training. All groups were evaluated before and after the 16 weeks of intervention in the following aspects: quantification of serum lipids, testosterone, fasting insulin and blood glucose; physical fitness through cardiopulmonary testing; analysis of heart rate variability (HRV) by linear (time domain and frequency domain) and non-linear (symbolic analysis) methods, analysis of blood pressure variability (BPV) and spontaneous baroreflex sensitivity (BRS).

RESULTS

The final analysis, each group comprised 25 individuals. All groups had similar baseline parameters. After 16 weeks, intragroup comparison showed that the MICT and HIIT groups had a reduction in baseline heart rate (P < 0.001; P < 0.001, respectively) and testosterone levels P < 0.037; P < 0.012, respectively) associated with an increase in VO2_peak (MICT, P < 0.001; HIIT, P < 0.001). The MICT (P < 0.36) and HIIT (P < 0.17) groups also showed an increase in cardiac vagal modulation, however only observed in the non-linear analysis. The intergroup comparison showed no differences between the MICT and HIIT groups in any of the hormonal, metabolic and autonomic parameters evaluated, including testosterone, peak oxygen uptake (VO2_peak), HRV, BPV and BRS.

CONCLUSION

HIIT and MICT showed similar results for the different parameters evaluated. This suggests that both training protocols can be recommended for the treatment of PCOS. Brazilian Clinical Trials Registry (RBR-78qtwy).

Efficacy of high-intensity interval training on cardiac autonomic modulation in cardiovascular diseases and lifestyle disorders: a systematic review and meta-analysis

The study aims to investigate the literature on the effect of high-intensity interval training (HIIT) on cardiac autonomic function in individuals with cardiovascular disease (CVD) and lifestyle disorders. We performed electronic database search from CENTRAL, WoS, Scopus, Pubmed, and PEDro up to 25th February 2021. Randomised control trials/quasi-experimental trials/cross-over trials that assessed the effects of HIIT with control/alternative treatment on cardiac autonomic control were included in this review. A total of 11 studies were included for qualitative analysis and among them, 8 were quantitatively analysed. A random-effect model of standardised mean difference (SMD) and mean difference of the respective outcome measures for cardiac autonomic control was determined. The findings of the qualitative analysis revealed the beneficial effects of HIIT on cardiac autonomic modulation. However, the majority of the studies had an unclear or high risk of bias for randomisation, concealment methods, and blinding of participants to the intervention that could have influenced the interpretation of the findings. The SMD revealed a significant effect of HIIT on standard deviation of N-N intervals (SDNN) (ms) [SMD: 0.40, 95% confidence interval (CI): -0.001 to 0.80, P=0.05], high frequency power (HF) (ms2) [0.46, 95% CI: 0.17 to 0.76, P=0.002], and ratio of low and high frequency power, (LF/HF) [-0.80, 95% CI: -1.27 to -0.33, P=0.0008]. In conclusion, HIIT may effectively modulate cardiac autonomic function by increasing parasympathetic dominance, sympathetic withdrawal, and sympathovagal balance in individuals with CVD and lifestyle disorders. The study has a PROSPERO registration number: CRD42021231225

Effects of different exercise interventions on heart rate variability and cardiovascular health factors in older adults: a systematic review

BACKGROUND

Aging impairs physiological processes in the autonomic nervous, endocrine, and cardiovascular systems which are associated with increased risk of cardiovascular disease. Heart rate variability (HRV), the beat-to-beat variations of successive heartbeats, is an indicator of cardiac autonomic control and cardiovascular health. Physical activity has beneficial effects on cardiovascular health. However, no review has been conducted to summarize the effects of different exercise modalities on HRV in older adults. Therefore, the aim of this systematic review was to summarize the effects of endurance, resistance, coordinative, and multimodal exercise interventions on resting HRV and secondary health factors in healthy older adults aged 60 years in average and over.

METHODS

Five databases (PubMed, Scopus, SPORTDiscus, Ovid, and Cochrane Library) were searched for eligible studies published between 2005 and September 8th, 2020. Two reviewers independently assessed the studies for potential inclusion. Outcome measures were changes in resting HRV indices, baroreflex sensitivity, blood pressure, body fat, body mass, body mass index, cardiac output, distance in the six-minute walking test, stroke volume, total peripheral resistance, and VO2 max or VO2 peak from pre to post intervention. The methodological quality of the final data set was assessed using two scales (TESTEX and STARDHRV). This review was registered in PROSPERO: CRD42020206606.

RESULTS

The literature search retrieved 3991 articles, of which 13 were included in the review. Five studies used multimodal, three studies endurance, two studies resistance, two studies coordinative, and one study used an endurance and a resistance training intervention. The majority of the studies revealed significant positive effects on cardiac autonomic control, except for the resistance training interventions. All exercise modalities improved secondary health factors. The methodological quality assessment revealed a few criteria to improve the quality of and comparability between studies.

CONCLUSION

This systematic review revealed beneficial effects on cardiac autonomic control in healthy older adults through endurance, coordinative, and multimodal training but not through resistance training. Secondary health factors improved after all types of physical interventions. Future investigations should more thoroughly adhere to methodological standards of exercise interventions and ECG recording for the assessment of autonomic regulation.

The Effects Of Exercise Training On Physical, Physiological And Psychological Risk Factors Of Patients With Cardiovascular Disease

Background — Exercise training is an important component of wellness for individuals diagnosed with cardiovascular disease (CVD). Exercise may have an effect on cardiovascular risk factors such as hypertension, lipid levels, and other associated physical, psychological, and physiological risk factors. Exercise intensity may further impact those risk factors. Aim — This narrative review of the literature aims to identify the effect of regular physical exercise on modifying risk factors for CVD and increased morbidity and mortality related to CVD. Methods — Published English-language papers from 2011 to 2020, available in Scopus, PubMed, Cochrane, Google Scholar, and Thompson were included in this review. Keywords for this search were exercise training, cardiovascular disease, hypertension, physical function, physiological, and psychological risk factors. Conclusions — Exercise training may be a cost-effective intervention that improves the physical, physiological, and psychological risk factors and the motor function of patients with cardiovascular disease.

Exercise Effects On Cardiovascular Disease: From Basic Aspects To Clinical Evidence

Cardiovascular (CV) disease (CVD) remains the leading cause of major morbidity and CVD- and all-cause mortality in most of the world. It is now clear that regular physical activity (PA) and exercise training (ET) induces a wide range of direct and indirect physiologic adaptations and pleiotropic benefits for human general and CV health. Generally, higher levels of PA, ET, and cardiorespiratory fitness (CRF) are correlated with reduced risk of CVD, including myocardial infarction, CVD-related death, and all-cause mortality. Although exact details regarding the ideal doses of ET, including resistance and, especially, aerobic ET, as well as the potential adverse effects of extreme levels of ET, continue to be investigated, there is no question that most of the world's population have insufficient levels of PA/ET, and many also have lower than ideal levels of CRF. Therefore, assessment and promotion of PA, ET, and efforts to improve levels of CRF should be integrated into all health professionals' practices worldwide. In this state-of-the-art review, we discuss the exercise effects on many areas related to CVD, from basic aspects to clinical practice.

Effects of Different Exercise Interventions on Cardiac Autonomic Control and Secondary Health Factors in Middle-Aged Adults: A Systematic Review

This systematic review was conducted in accordance with the PRISMA guidelines to summarize the existing literature on the effects of different exercise interventions on cardiac autonomic control and secondary health factors. Resting heart rate variability (HRV) was used as indicator of cardiac autonomic control. Secondary factors were related to factors that contribute to cardiovascular health. Studies examining the effects of endurance, resistance, multimodal, or coordinative training interventions in healthy participants aged between 45 and 60 years old on average were considered. The methodological quality of the studies was examined using two assessment scales (TESTEX and STARD_HRV). PROSPERO registration number: CRD42020206606. The literature review retrieved eight studies fulfilling all inclusion criteria. Cardiac autonomic control and cardiovascular health improved after endurance and multimodal interventions. Resistance training had no significant impact on HRV or any secondary health factor. Coordinative exercise interventions showed inconclusive results regarding HRV but showed significant improvements in secondary health factors. The quality assessment tools revealed some methodological and reporting deficits. Despite the small number of studies, we suggest endurance and multimodal interventions including aerobic exercises for the enhancement of cardiac autonomic control and the reduction of cardiovascular risk in middle-aged adults. Further studies need to be conducted to examine the long-term effects of exercise in the midlife period.

WITHDRAWN: Research on the "integration of physical activity and medicine" prevention scheme of chronic disease population based on health risk assessment

Ahead of Print article withdrawn by publisher.

Effects of Different Training Interventions on Heart Rate Variability and Cardiovascular Health and Risk Factors in Young and Middle-Aged Adults: A Systematic Review

Introduction: Heart rate variability (HRV), the beat-to-beat variation of adjacent heartbeats, is an indicator of the function of the autonomic nervous system (ANS). Increased HRV reflects well-functioning of autonomic control mechanism and cardiovascular health. The aim of this systematic review is to provide a systematic overview of the effects of different physical training modalities on resting HRV and cardiovascular health and risk factors (i.e., baroreflex sensitivity, body fat, body mass, body mass index, blood pressure, heart rate recovery, VO₂ max, and VO₂ peak) in young and middle-aged (mean age of the studies samples up to 44 years), healthy adults.

Methods: A systematic review in accordance with the PRISMA guidelines was performed. Studies investigating the effects of different physical interventions (endurance, resistance, high-intensity, coordinative, or multimodal training) on HRV were included. Trials were considered eligible if the intervention lasted for at least 4 weeks and participants were regarded as general healthy. Five electronic databases were searched from 2005 to September 8th, 2020. The methodological quality of eligible studies was assessed by two study quality and reporting assessment scales (TESTEX and STARD_HRV). PROSPERO registration number: CRD42020206606.

Results: Of 3,991 retrieved records, 26 were considered eligible and analyzed. Twelve studies used an endurance training (of which three included high-intensity sessions), six studies resistance training, four studies coordinative training, two studies high-intensity training, and two studies used a multimodal intervention. Overall, the results showed for all types of intervention an improvement in linear and non-linear HRV parameters and cardiovascular health and risk factors. However, quality assessment revealed some methodological and reporting deficits.

Conclusion: This systematic review highlights the benefits of different types of physical training interventions on autonomic function and health parameters in young and middle-aged, healthy adults. In conclusion, higher training intensities and frequencies are more likely to improve HRV. For future studies, we recommend adhering to the criteria of methodological standards of exercise interventions and HRV measurements and encourage the use of non-linear HRV parameters.

Adiposity and physical activity are related to heart rate variability: the African-PREDICT study

BACKGROUND

Physical inactivity contributes significantly to the development of obesity-related cardiovascular disease. Adiposity may lead to reduced heart rate variability (HRV), whereas increased physical activity (PA) has the potential to improve autonomic activity. These associations remain largely unexplored in healthy individuals. We therefore investigated whether adiposity and physical activity (PA) are associated with reduced heart rate variability (HRV) in young adults.

MATERIALS AND METHODS

We examined 403 black and 461 white healthy adults (aged 20-30 years) for HRV, including standard deviation of normal RR intervals (SDNN) and root mean square of successive differences (RMSSD). We measured adiposity, PA levels and blood pressure (BP). Body mass index (BMI) of ≥ 30 kg/m² indicated obesity.

RESULTS

Participants with obesity had lower mean HRV than normal weight (SDNN [95% CI]; 138 [131-145]s vs 161 [158-165]ms), where those with the highest PA had higher SDNN (164 [160-169]ms) and RMSSD (51 [49-53]ms) than the least active individuals (150 [146-155]s) and 46 [44-48]ms)(all P < .01). BMI, waist circumference and body fat associated with lower SDNN (P < .001). With each unit increase of vigorous PA, a favourable higher RMSSD was found (P < .05). One unit increase in diastolic BP was associated with decreased SDNN and RMSSD (P < .001). These findings remained significant in multivariable-adjusted analyses.

CONCLUSIONS

Adiposity and low PA associated independently with depressed autonomic activity in young healthy adults. Sympathovagal imbalance seems to already contribute to elevated diastolic BP at young ages. Our study supports population-based prevention programmes in young adults, improving PA and healthy diet, to curb the development of cardiovascular disease.

Autonomic Rehabilitation: Adapting to Change

Adaption to changes of external environment or internal health, the body-mind connection, or autonomic nervous system must be flexible and healthy. Population health studies with wearable technology and remote monitoring will lead to paradigm shifts in how to approach the physiology of emotion. Heart rate variability as a whole health biomarker could emerge as a foundation for a process beginning with objective habits and skills of real-time modulation with focused breathing for healthier decision making and autonomic health trajectory change. Physical medicine and rehabilitation is uniquely poised to refine an autonomic rehabilitation process in an integrative manner to help individuals adapt.

Short-term aerobic training improves heart rate variability in men living with HIV: a pre-post pilot study

BACKGROUND

Heart rate variability (HRV) a feasible predictor of prognosis in cardiovascular outcomes shown to be reduced in people living with HIV (PLWH).

OBJECTIVE

This study sought to understand the effects of short-term aerobic training (AT) on the resting HRV and endothelial function in this population.

METHODS

PLWH performed 24 sessions of AT protocol. The protocol consists of 40 min of treadmill (60 to 80% of the VO_2max), 3 times per week, for 8 weeks. HRV (standard deviation of all normal RR intervals - SDNN; root mean square of the successive differences - rMSSD; low frequency - LF; high frequency - HF; LF:HF ratio) and endothelial function parameters were evaluated by EndoPAT system pre and post intervention.

RESULTS

7 men, the median age of the sample was 49 years (range, 38-68 years), completed the protocol. AT improved resting HRV parameters: SDNN (p = 0.02, power analysis (PA) 0.54), rMSSD (p = 0.02, PA = 0.99), LF (p = 0.02, PA = 0.85). HF, LF:HF ratio and endothelial function parameters showed no changes.

CONCLUSIONS

The results suggest the short-term AT may improve HRV in men living with HIV.

Chronic Pain and Premature Aging - The Moderating Role of Physical Exercise

Chronic pain induces a multitude of harmful effects; recently it has been suggested that chronic pain is also associated with premature aging, manifested in shortened telomere length (TL). However, evidence for this hypothesis is scarce and inconsistent. The aim was twofold: 1) Investigate whether chronic pain is associated with premature aging, and 2) Determine whether physical exercise (PE) moderates this association if it exists. Participants were 116 male subjects, with (n = 67) and without chronic pain (n = 49). Blood samples for TL analysis were collected and participants were interviewed and completed questionnaires. As a part of the cohort, we included people with physical disability; this variable was controlled in the analysis. The TL of individuals with chronic pain was significantly shorter than that of pain-free individuals. Regression analysis revealed a significant moderating effect of PE on chronic pain and TL, above and beyond the effects of disability, age, and weight. Whereas chronic pain was associated with shorter telomeres in participants who did not exercise, this association was nonsignificant among participants who did exercise. The results suggest that chronic pain is associated with premature ageing; however, PE may mitigate this association and may protect individuals against the harmful effects of chronic pain. PERSPECTIVE: The study suggests that it is important to monitor signs of premature ageing among chronic pain patients as they are at risk. However, chronic pain patients may benefit from regular PE in this respect as it may moderate premature ageing.

Physical Activity Promotes Health and Reduces Cardiovascular Mortality in Depressed Populations: A Literature Overview

Major depression is associated with premature mortality, largely explained by heightened cardiovascular burden. This narrative review summarizes secondary literature (i.e., reviews and meta-analyses) on this topic, considering physical exercise as a potential tool to counteract this alarming phenomenon. Compared to healthy controls, individuals with depression consistently present heightened cardiovascular risk, including "classical" risk factors and dysregulation of pertinent homeostatic systems (immune system, hypothalamic-pituitary-adrenal axis and autonomic nervous system). Ultimately, both genetic background and behavioral abnormalities contribute to explain the link between depression and cardiovascular mortality. Physical inactivity is particularly common in depressed populations and may represent an elective therapeutic target to address premature mortality. Exercise-based interventions, in fact, have proven effective reducing cardiovascular risk and mortality through different mechanisms, although evidence still needs to be replicated in depressed populations. Notably, exercise also directly improves depressive symptoms. Despite its potential, however, exercise remains under-prescribed to depressed individuals. Public health may be the ideal setting to develop and disseminate initiatives that promote the prescription and delivery of exercise-based interventions, with a particular focus on their cost-effectiveness.

The effect of green walking on heart rate variability: A pilot crossover study

We investigated the effects of regular walking in green and suburban environments on heart rate variability (HRV) and blood pressure (BP) in middle-aged adults. Twenty-three adults participated in a non-randomized crossover experiment comprised of once-weekly 50-min moderate-intensity walking sessions. Separated by a two-week washout period, participants walked for three weeks in each of two treatment conditions (green and suburban) in a local arboretum and suburban sidewalks of Chaska, MN. Eleven participants completed green walking first and 12 suburban walking first. Walks were split into 15-min intra-walk phases, with phases representing each walk's beginning, middle, and final 15-min. Repeated measures linear mixed models evaluated (1) HRV phase differences between treatments and HRV change within treatments, and (2) pre- and post-walk BP differences between treatments and pre-to post-walk BP changes. Intra-walk phase analyses revealed higher HRV during green walking vs. suburban walking during phase 2 (p < 0.0001) and phase 3 (p = 0.02). Less HRV reduction was seen between intra-walk phases 1 and 2 during green vs. suburban walking (p = 0.02). Pre-to post-walk changes revealed decreased mean systolic BP for both green (p = 0.0002) and suburban (p = 0.003) walking conditions, but not for diastolic BP. Post-walk BP results were similar after both green walking and suburban walking. In summary, walking sessions in a green environment elicited greater beneficial HRV responses compared to a suburban environment. Additionally, walking in either environment, green or suburban, promoted reductions in systolic BP.

Comparative Effects of High-Intensity Interval Training vs Moderate-Intensity Continuous Training in Phase III of a Tennis-Based Cardiac Rehabilitation Program: A Pilot Randomized Controlled Trial

The aim of the present study was to investigate the effects of two tennis-based cardiac rehabilitation programs using two protocols: high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) in the body composition, physical fitness, heart rate variability, and health-related quality of life. It was performed as a single-blinded randomized controlled trial of 21 people with acute coronary syndrome. The 12-week cardiac rehabilitation program consisted of three sessions per week of 60 min with the main part consisting of 10 sets of 15 s with 15 s of active recovery at 85%–90% of their maximum heart rate or 40 min at 70%–85% of their maximum heart rate in the HIIT and the MICT groups, respectively. Results show that both cardiac rehabilitation programs improved the agility and the mental components of the health-related quality of life (p-value < 0.05). The HIIT protocol also showed a significant improvement in the flexibility of upper and lower limbs (p-value < 0.05). Moreover, significant group × time interaction was found in the handgrip strength in favor of the HIIT group (p-value = 0.035). Nevertheless, no significant effects on cardiorespiratory fitness or heart rate variability were found. Importantly, no adverse event was detected, so HIIT appears to be a safe and effective alternative for the rehabilitation of patients with acute coronary syndrome.

Association between Micronutrients and Heart Rate Variability: A Review of Human Studies

Heart rate variability (HRV) is a measure of the variation between consecutive heartbeats. It provides a marker of the interplay between the parasympathetic and sympathetic nervous systems, and there is an increasing body of evidence confirming an increased HRV is associated with better mental and physical health. HRV may be a useful marker of stress as it represents the ability of the heart to respond to a variety of physiological and environmental stimuli. HRV tends to decrease as we age and is positively associated with physical activity, fitness, and healthier lifestyles. The relation between HRV and micronutrients (vitamins and minerals) has also received some attention in the research literature. In this review, cross-sectional and interventional studies on human populations examining the relation between HRV and micronutrients are appraised. Micronutrients identified and examined in this review include vitamins D, B-12, C, and E; the minerals magnesium, iron, zinc, and coenzyme Q10; and a multivitamin-mineral formula. Due to the paucity of research and significant heterogeneity in studies, definitive conclusions about the effects of these micronutrients on HRV cannot be made at this time. However, there is accumulating evidence suggesting deficiencies in vitamins D and B-12 are associated with reduced HRV, and zinc supplementation during pregnancy can have positive effects on HRV in offspring up until the age of 5 y. To further elucidate the relation between micronutrients and HRV, additional robustly designed and adequately powered studies are required.

Effects of exergames on heart rate variability of women with fibromyalgia: A randomized controlled trial

The objective of the present manuscript was to evaluate the effects of 24-weeks exergame intervention on the heart rate variability (HRV) of women with fibromyalgia. First, 56 women with fibromyalgia were assessed for eligibility. A total of 55 women fulfilled the inclusion criteria and participated in this single-blinded, randomized controlled trial. A 24-weeks of exergames were completed by the exercise group in the university facilities. It was focused on the mobility, postural control, upper and lower limbs coordination, aerobic fitness and strength. A total of 120 min per week, divided into two sessions of 60 min, was completed. A short-term 5 min record at rest was used to assess the HRV. Time (SDNN and RMSSD) and non-linear indexes (Higuchi´s Fractal Dimension, SD1, SD2, ln stress score, and SD1/SD2) of HRV were extracted. Fifty participants (achieving an 89.28% of adherence), recruited from the local fibromyalgia association completed the study. They were randomly divided into an exercise (age = 54.04[8.45]) and a control group (52.72[9.98]). Significant interaction (group*time) effects in SDNN, ln stress score, SD2, and SD1/SD2 ratio were found. The EG showed an increase of SDNN and a decreased ln stress score and SD2. The CG showed an increased ln stress score, SD1/SD2. In conclusion, 24-weeks of exergame intervention based on the tool VirtualEx-FM improved the autonomic control in patients with fibromyalgia. However, significant effects on Higuchi´s fractal dimension were not found. This is the first study using exergame as a therapy in women with fibromyalgia which has led to an improvement the autonomic balance in these patients.

Effects of 8-Week Whole-Body Vibration Training on the HbA1c, Quality of Life, Physical Fitness, Body Composition and Foot Health Status in People with T2DM: A Double-Blinded Randomized Controlled Trial

The aim of this study was to analyze the effects of an 8-week whole-body vibration (WBV) on the quality of life, physical fitness, body composition, glycosylate hemoglobin (HbA1c), lipid profile, and foot health status in people with type II diabetes mellitus (T2DM). It was performed as a double-blinded randomized controlled trial of 90 people with T2DM. Primary care facilities were used. The 8-week WBV training consisted of maintaining a knee flexion at 45° during five to nine series of 30-60 s in a vibration frequency that oscillated between 12.5-18.5 and 30 s of recovery between series. The placebo group had to perform the same protocol but without vibration. Participants performed the protocol three times per week. The WBV training significantly reduced the fat mass (%) of people with T2DM. However, significant effects of WBV training were not found in the quality of life, physical fitness, foot health status, lipid profile, blood pressure, fasting blood glucose, or HbA1c. Nevertheless, within groups enhances were found in HbA1c, blood pressure, fasting blood glucose, foot health status, health-related quality of life, timed-up and go test, and chair-stand test in both WBV and placebo groups. WBV was shown to be beneficial for reducing the fat mass and lipid profile of people with T2DM. The improvements of the placebo group could be due to both the social benefits of enrolling in an intervention and the physical fitness benefits of isometric contractions. Further studies are needed to clarify the effects of WBV and to establish a dose-response relationship in people with T2DM.

Exercise benefits in cardiovascular disease: beyond attenuation of traditional risk factors

Despite strong scientific evidence supporting the benefits of regular exercise for the prevention and management of cardiovascular disease (CVD), physical inactivity is highly prevalent worldwide. In addition to merely changing well-known risk factors for systemic CVD, regular exercise can also improve cardiovascular health through non-traditional mechanisms. Understanding the pathways through which exercise influences different physiological systems is important and might yield new therapeutic strategies to target pathophysiological mechanisms in CVD. This Review includes a critical discussion of how regular exercise can have antiatherogenic effects in the vasculature, improve autonomic balance (thereby reducing the risk of malignant arrhythmias), and induce cardioprotection against ischaemia-reperfusion injury, independent of effects on traditional CVD risk factors. This Review also describes how exercise promotes a healthy anti-inflammatory milieu (largely through the release of muscle-derived myokines), stimulates myocardial regeneration, and ameliorates age-related loss of muscle mass and strength, a frequently overlooked non-traditional CVD risk factor. Finally, we discuss how the benefits of exercise might also occur via promotion of a healthy gut microbiota. We argue, therefore, that a holistic view of all body systems is necessary and useful when analysing the role of exercise in cardiovascular health.

Changes in negative affect and changes in heart rate variability among low-income latinos with type 2 diabetes in a randomized, controlled stress management trial

BACKGROUND

Structural equation modeling examined the relationship between change in negative affect (NA) and change in heart rate variability (HRV) among 121 Latinos with type 2 diabetes.

METHODS

This study leveraged data from the Community Health Workers Assisting Latinos Manage Stress and Diabetes (CALMSD) study which compared diabetes education vs diabetes education plus stress management. Participants completed surveys of NA at baseline and again 8-10 weeks later. They also wore 7‑lead, 3-channel ambulatory ECG monitors for 24 h at both time points. The latent variable NA was modeled by observed scores on symptoms of depression, anxiety, diabetes distress, and wellbeing (reversed). The latent variable HRV was modeled by observed scores in the time domain (the standard deviation of the R-R interval [SDNN] and the root mean square of the successive differences [RMSSD]) and in the frequency domain, i.e., log-transformed ultra-low frequency, very-low frequency, low frequency, and high frequency.

RESULTS

At baseline, there were strong, negative cross-sectional associations between NA and HRV. Baseline NA predicted change in HRV, whereas baseline HRV did not predict change in NA. Controlling for fasting glucose and treatment assignment did not meaningfully alter the findings. Stress management improved NA but not HRV. At followup, a greater reduction (improvement) in NA was associated with a larger increase (improvement) in HRV, with a small-to-medium negative association that approached statistical significance.

CONCLUSIONS

Findings indicate a longitudinal relationship between NA and HRV, and suggest that improvement in one may be associated with improvement in the other.

Study protocol for a multicentre, controlled non-randomised trial: benefits of exercise physiology services for type 2 diabetes (BEST)

INTRODUCTION

Controlled trials support the efficacy of exercise as a treatment modality for chronic conditions, yet effectiveness of real-world Exercise Physiology services is yet to be determined. This study will investigate the efficacy and cost-effectiveness of services provided by Accredited Exercise Physiologists (AEPs) for clients with type 2 diabetes (T2D) in clinical practice.

METHODS AND ANALYSIS

A non-randomised, opportunistic control, longitudinal design trial will be conducted at ten Exercise Physiology Clinics. Participants will be individuals with T2D attending one of the Exercise Physiology Clinics for routine AEP services (exercise prescription and counselling) (intervention) or individuals with T2D not receiving AEP services (usual care) (control). The experimental period will be 6 months with measurements performed at baseline and at 6 months. Primary outcome measures will be glycosylated haemoglobin (HbA1c), resting brachial blood pressure (BP), body mass index, waist circumference, 6 min walk test, grip strength, 30 s sit to stand, Medical Outcomes Short-Form 36-Item Health Survey and Active Australia Questionnaire. Secondary outcomes will be medication usage, out-of-pocket expenses, incidental, billable and non-billable health professional encounters and work missed through ill health. Healthcare utilisation will be measured for 12 months prior to, during and 12 months after trial participation using linked data from Medicare Benefits Schedule and Pharmaceutical Benefits Scheme data.

ETHICS AND DISSEMINATION

The study is a multicentre trial comprising: University of Tasmania, University of New South Wales Lifestyle Clinic, University of Canberra, Baker Heart and Diabetes Institute (covered under the ethics approval of University of Tasmania Health and Medical Ethics Committee H0015266), Deakin University (Approval number: 2016-187), Australian Catholic University (2016-304R), Queensland University of Technology (1600000049), University of South Australia (0000035306), University of Western Australia (RA/4/1/8282) and Canberra Hospital (ETH.8.17.170). The findings of this clinical trial will be communicated via peer-reviewed journal articles, conference presentations, social media and broadcast media.

TRIAL REGISTRATION NUMBER

ACTRN12616000264482.

Physical activity and dietary interventions in diabetic neuropathy: a systematic review

PURPOSE

Diabetic neuropathy is a common and disabling disorder, and there are currently no proven effective disease-modifying treatments. Physical activity and dietary interventions in patients with diabetes and diabetic neuropathy have multiple beneficial effects and are generally low risk, which makes lifestyle interventions an attractive treatment option. We reviewed the literature on the effects of physical activity and dietary interventions on length-dependent peripheral neuropathy and cardiac autonomic neuropathy in diabetes.

METHODS

The electronic database PubMed was systematically searched for original human and mouse model studies examining the effect of either dietary or physical activity interventions in subjects with diabetes, prediabetes, or metabolic syndrome.

RESULTS

Twenty studies are included in this review. Fourteen studies were human studies and six were in mice. Studies were generally small with few controlled trials, and there are no widely agreed upon outcome measures.

CONCLUSIONS

Recent research indicates that dietary interventions are effective in modifying diabetic neuropathy in animal models, and there are promising data that they may also ameliorate diabetic neuropathy in humans. It has been known for some time that lifestyle interventions can prevent the development of diabetic neuropathy in type 2 diabetes mellitus subjects. However, there is emerging evidence that lifestyle interventions are effective in individuals with established diabetic neuropathy. In addition to the observed clinical value of lifestyle interventions, there is emerging evidence of effects on biochemical pathways that improve muscle function and affect other organ systems, including the peripheral nerve. However, data from randomized controlled trials are needed.

Influence of smoking on physical function, physical activity, and cardiovascular health parameters in patients with symptomatic peripheral arterial disease: A cross-sectional study

The aim of this study was to analyze the impact of smoking on physical activity, walking capacity, and cardiovascular health in patients with symptomatic peripheral arterial disease (PAD). This cross-sectional study included 180 patients with symptomatic PAD. Patients were classified into 3 groups according to smoking history: smoker (n = 39), ex-smoker (n = 113), and never smoker (n = 28). Physical activity levels, physical function, walking capacity, and cardiovascular health parameters (clinical blood pressure, arterial stiffness, and heart rate variability) were assessed. Smoker patients presented higher sympathetic modulation to the heart (low frequency of heart rate variability: smokers, 71 ± 17 nu; ex-smokers, 53 ± 32 nu; never smokers, 49 ± 21 nu, P < .05) and sympathovagal balance (smokers: 2.44 ± 2.76, ex-smokers: 1.14 ± 1.74, never smokers: 1.04 ± 0.99, P < .05) and lower parasympathetic modulation to the heart (high frequency of heart rate variability: smokers, 29 ± 27 nu; ex-smokers, 47 ± 32 nu; never smokers, 51 ± 21 nu, P < .05) than other patients. In conclusion, nonsignificant differences were observed on physical activity levels, physical function, blood pressure, and arterial stiffness (P > .05). Smoking impairs cardiac autonomic modulation in patients with symptomatic PAD.

Can an Exercise-Based Educational and Motivational Intervention be Durably Effective in Changing Compliance to Physical Activity and Anthropometric Risk in People with Type 2 Diabetes? A Follow-Up Study

AIMS

A nine-month motivational exercise-based intervention was previously offered to subjects with type 2 diabetes (T2D). A year after the end of the intervention, compliance to physical activity (PA) and anthropometric indices of participants were analyzed to evaluate the durability of its effects.

METHODS

PA levels, expressed as total energy expenditure per week, were assessed with the International Physical Activity Questionnaire (IPAQ). Changes in Body Mass Index (BMI), A Body Shape Index (ABSI), Hip Index (HI) z-scores, the relative mortality risk related to each of these measures, and a combined Anthropometric Risk Index (ARI) were also evaluated.

RESULTS

Of a total of the 52 subjects examined (67.9% males, mean age 61.8 ± 6.0), 46 (88.4%) were still sufficiently active as defined by IPAQ thresholds at follow-up. PA levels, anthropometric indices and related risks improved at follow-up in respect to the baseline and to the end of the intervention, although only PA levels, BMI and related measures, and ARI risk changed significantly. Habitual PA increased significantly after the intervention (p < 0.01) and this increase correlated with changes in BMI z-scores (r = -0.29, p = 0.04). BMI risk was significantly lower (p < 0.01) in participants still active at follow-up.

CONCLUSIONS

This study testifies to the persistence of compliance to PA and health benefits of a combined exercise-based and motivational intervention in subjects with T2D.

Update on the Impact, Diagnosis and Management of Cardiovascular Autonomic Neuropathy in Diabetes: What Is Defined, What Is New, and What Is Unmet

The burden of diabetic cardiovascular autonomic neuropathy (CAN) is expected to increase due to the diabetes epidemic and its early and widespread appearance. CAN has a definite prognostic role for mortality and cardiovascular morbidity. Putative mechanisms for this are tachycardia, QT interval prolongation, orthostatic hypotension, reverse dipping, and impaired heart rate variability, while emerging mechanisms like inflammation support the pervasiveness of autonomic dysfunction. Efforts to overcome CAN under-diagnosis are on the table: by promoting screening for symptoms and signs; by simplifying cardiovascular reflex tests; and by selecting the candidates for screening. CAN assessment allows for treatment of its manifestations, cardiovascular risk stratification, and tailoring therapeutic targets. Risk factors for CAN are mainly glycaemic control in type 1 diabetes mellitus (T1DM) and, in addition, hypertension, dyslipidaemia, and obesity in type 2 diabetes mellitus (T2DM), while preliminary data regard glycaemic variability, vitamin B12 and D changes, oxidative stress, inflammation, and genetic biomarkers. Glycaemic control prevents CAN in T1DM, whereas multifactorial intervention might be effective in T2DM. Lifestyle intervention improves autonomic function mostly in pre-diabetes. While there is no conclusive evidence for a disease-modifying therapy, treatment of CAN manifestations is available. The modulation of autonomic function by SGLT2i represents a promising research field with possible clinical relevance.

Unsupervised high-intensity interval training improves glycaemic control but not cardiovascular autonomic function in type 2 diabetes patients: A randomised controlled trial

BACKGROUND

This is the first randomised controlled trial to assess the impact of unsupervised high-intensity interval training on cardiovascular autonomic function in adults with type 2 diabetes.

METHODS

A total of 22 individuals with type 2 diabetes (age 60 ± 2 years, 17 males) lay in a supine position for 20 min for evaluation of cardiovascular autonomic function, which included (1) time domain measures of heart rate variability, (2) frequency domain measures of heart rate variability and blood pressure variability and (3) baroreflex receptor sensitivity. Participants were randomised into 12 weeks of high-intensity interval training (3 sessions/week) or standard care control group.

RESULTS

After 12 weeks, the between-group change in HbA1c (%) was significant (high-intensity interval training: 7.13 ± 0.31 to 6.87 ± 0.29 vs Control: 7.18 ± 0.17 to 7.36 ± 0.21, p = 0.03). There were no significant changes in measures of heart rate variability; R-R interval (ms) (high-intensity interval training: 954 ± 49 to 973 ± 53 vs Control: 920 ± 6 to 930 ± 32, p = 0.672), low frequency/high frequency (high-intensity interval training: 0.90 ± 0.21 to 0.73 ± 0.07 vs Control: 1.20 ± 0.29 to 1.00 ± 0.17, p = 0.203), or blood pressure variability; systolic blood pressure low frequency/high frequency (high-intensity interval training: 0.86 ± 0.21 to 0.73 ± 0.10 vs Control: 1.06 ± 0.26 to 0.91 ± 0.14, p = 0.169). At baseline, HbA1c was negatively correlated with baroreflex receptor sensitivity ( r = -0.592, p < 0.01).

CONCLUSION

High-intensity interval training improves glycaemic control but has limited effect on cardiovascular autonomic regulation in patients with type 2 diabetes.

The Effects of Passive Simulated Jogging on Short-Term Heart Rate Variability in a Heterogeneous Group of Human Subjects

Background

Heart rate variability (HRV) reflects neural balance between sympathetic and parasympathetic autonomic nervous systems (ANS). Reduced HRV occurs in several chronic diseases and physical inactivity. External addition of pulses to the circulation restores HRV. A new method to add pulses to the circulation can be accomplished with a passive simulated jogging device (JD). We hypothesized that application of JD might increase HRV in seated and supine postures in a heterogeneous group of volunteer subjects.

Methods

Twenty ambulatory persons (age range 31-88) were recruited. The physical activity intervention (JD) moved the feet in a repetitive and alternating manner; upward movement of the pedal is followed by a downward movement of the forefoot tapping against a semirigid bumper to simulate tapping of feet against the ground during jogging. Each subject underwent four, 30 min sessions in seated and supine postures with the active JD and same with Sham. HRV was assessed at baseline (BL), and Recovery (REC) from analysis of an electrocardiogram. Time domain variables were computed, namely, standard deviation of all normal RR intervals (SDNN) and square root of the mean of the sum of the squares of differences between adjacent RR intervals (RMSSD). Frequency domain measures were determined using a standard Fast Fourier spectral analysis, as well as parameters of Poincaré plots.

Results

Thirty minutes of JD significantly increased time domain measures and Poincaré parameters of HRV in both seated and supine postures. Frequency domain parameters showed no change. The effects of JD on HRV measures were not affected by age, gender, or posture.

Conclusion

The passive simulated jogging device increased HRV in both seated and supine postures. This intervention that provided effortless physical activity is a novel method to harness the beneficial effects of increasing HRV.

Sleep disturbances in diabetic peripheral neuropathy patients: a clinical and polysomnographic study

Background

Disordered sleep breathing is a common complication of diabetic peripheral neuropathy (DPN) manifested by excessive daytime sleepiness, morning headache, morning dizziness, cognitive decline, and mood changes.

Methods

This study was performed on 30 non-obese type 2 diabetic patients; 20 with clinically evident DPN and 10 without. Ten age-, sex-, and body mass index-matched healthy control subjects were also included. Patients and control were subjected to history taking, neurological examination, glycated hemoglobin, and clinical assessment of the sensori-motor manifestations by the neuropathy symptom score and neuropathy disability score. The autonomic nervous system was evaluated clinically by the systolic blood pressure response to standing and heart rate response to each of standing, Valsalva, and deep breath. Finally, sleep was assessed by one-night polysomnogram (PSG) followed by multiple sleep latency test in the next day.

Results

The study showed significant increase in sleep apnea syndromes in diabetic peripheral neuropathy patients compared to diabetic neuropathy free patients and healthy control (p < 0.0001). The sleep apnea was mainly obstructive and to a little extent mixed (obstructive/central) sleep apnea. The severity of sleep PSG abnormalities was positively correlated with the severities of sensory, motor, and autonomic manifestations.

Conclusions

Non-obese type 2 diabetic patients complicated by peripheral neuropathy especially those having dysautonomia are at increased risk of developing sleep disordered breathing resulting in their excessive daytime sleepiness, decreased productivity, and poor glycemic control.

Physical Exercise in Major Depression: Reducing the Mortality Gap While Improving Clinical Outcomes

Major depression shortens life while the effectiveness of frontline treatments remains modest. Exercise has been shown to be effective both in reducing mortality and in treating symptoms of major depression, but it is still underutilized in clinical practice, possibly due to prevalent misperceptions. For instance, a common misperception is that exercise is beneficial for depression mostly because of its positive effects on the body ("from the neck down"), whereas its effectiveness in treating core features of depression ("from the neck up") is underappreciated. Other long-held misperceptions are that patients suffering from depression will not engage in exercise even if physicians prescribe it, and that only vigorous exercise is effective. Lastly, a false assumption is that exercise may be more harmful than beneficial in old age, and therefore should only be recommended to younger patients. This narrative review summarizes relevant literature to address the aforementioned misperceptions and to provide practical recommendations for prescribing exercise to individuals with major depression.