The Role of Exercise in the Treatment of Cardiovascular Disease Associated with Type 2 Diabetes Mellitus

Development and validation of nomograms for predicting cardiovascular disease risk in patients with prediabetes and diabetes

This study aimed to develop and validate distinct nomogram models for assessing CVD risk in individuals with prediabetes and diabetes. In a cross-sectional study design, we examined data from 2294 prediabetes and 1037 diabetics who participated in the National Health and Nutrition Examination Survey, which was conducted in the United States of America between 2007 and 2018. The dataset was randomly divided into training and validation cohorts at a ratio of 0.75-0.25. The Boruta feature selection method was used in the training cohort to identify optimal predictors for CVD diagnosis. A web-based dynamic nomogram was developed using the selected features, which were validated in the validation cohort. The Hosmer-Lemeshow test was performed to assess the nomogram's stability and performance. Receiver operating characteristics and calibration curves were used to assess the effectiveness of the nomogram. The clinical applicability of the nomogram was evaluated using decision curve analysis and clinical impact curves. In the prediabetes cohort, the CVD risk prediction nomogram included nine risk factors: age, smoking status, platelet/lymphocyte ratio, platelet count, white blood cell count, red cell distribution width, lactate dehydrogenase level, sleep disorder, and hypertension. In the diabetes cohort, the CVD risk prediction nomogram included eleven risk factors: age, material status, smoking status, systemic inflammatory response index, neutrophil-to-lymphocyte ratio, red cell distribution width, lactate dehydrogenase, high-density lipoprotein cholesterol, sleep disorder, hypertension, and physical activity. The nomogram models developed in this study have good predictive and discriminant utility for predicting CVD risk in patients with prediabetes and diabetes.

Aerobic Exercise Inhibited P2X7 Purinergic Receptors to Improve Cardiac Remodeling in Mice With Type 2 Diabetes

Background: Diabetic cardiomyopathy (DCM), the main complication of diabetes mellitus, presents as cardiac dysfunction by ventricular remodeling. In addition, the inhibition of P2X7 purinergic receptors (P2X7R) alleviates cardiac fibrosis and apoptosis in Type 1 diabetes. However, whether exercise training improves cardiac remodeling by regulating P2X7R remains unknown. Methods: Db/db mice spontaneously induced with type 2 diabetes and high-fat diet (HFD) and mice with streptozotocin (STZ)-induced type 2 diabetes mice were treated by 12-week treadmill training. Cardiac functions were observed by two-dimensional echocardiography. Hematoxylin-eosin staining, Sirius red staining and transmission electron microscopy were respectively used to detect cardiac morphology, fibrosis and mitochondria. In addition, real-time polymerase chain reaction and Western Blot were used to detect mRNA and protein levels. Results: Studying the hearts of db/db mice and STZ-induced mice, we found that collagen deposition and the number of disordered cells significantly increased compared with the control group. However, exercise markedly reversed these changes, and the same tendency was observed in the expression of MMP9, COL-I, and TGF-β, which indicated cardiac fibrotic and hypertrophic markers, including ANP and MyHC expression. In addition, the increased Caspase-3 level and the ratio of Bax/Bcl2 were reduced by exercise training, and similar results were observed in the TUNEL test. Notably, the expression of P2X7R was greatly upregulated in the hearts of db/db mice and HFD + STZ-induced DM mice and downregulated by aerobic exercise. Moreover, we indicated that P2X7R knock out significantly reduced the collagen deposition and disordered cells in the DM group. Furthermore, the apoptosis levels and TUNEL analysis were greatly inhibited by exercise or in the P2X7R^-/- group in DM. We found significant differences between the P2X7R^-/- + DM + EX group and DM + EX group in myocardial tissue apoptosis and fibrosis, in which the former is significantly milder. Moreover, compared with the P2X7R^-/- + DM group, the P2X7R^-/- + DM + EX group represented a lower level of cardiac fibrosis. The expression levels of TGF-β at the protein level and TGF-β and ANP at the genetic level were evidently decreased in the P2X7R^-/- + DM + EX group. Conclusion: Aerobic exercise reversed cardiac remodeling in diabetic mice at least partly through inhibiting P2X7R expression in cardiomyocytes.

Teleoperation of an Ankle-Foot Prosthesis With a Wrist Exoskeleton

OBJECTIVE

We aimed to develop a system for people with amputation that non-invasively restores missing control and sensory information for an ankle-foot prosthesis.

METHODS

In our approach, a wrist exoskeleton allows people with amputation to control and receive feedback from their prosthetic ankle via teleoperation. We implemented two control schemes: position control with haptic feedback of ankle torque at the wrist; and torque control that allows the user to modify a baseline torque profile by moving their wrist against a virtual spring. We measured tracking error and frequency response for the ankle-foot prosthesis and the wrist exoskeleton. To demonstrate feasibility and evaluate system performance, we conducted an experiment in which one participant with a transtibial amputation tracked desired wrist trajectories during walking, while we measured wrist and ankle response.

RESULTS

Benchtop testing demonstrated that for relevant walking frequencies, system error was below human perceptual error. During the walking experiment, the participant was able to voluntarily follow different wrist trajectories with an average RMS error of 1.55 ^° after training. The ankle was also able to track desired trajectories below human perceptual error for both position control (RMSE = 0.8 ^°) and torque control (RMSE = 8.4%).

CONCLUSION

We present a system that allows a user with amputation to control an ankle-foot prosthesis and receive feedback about its state using a wrist exoskeleton, with accuracy comparable to biological neuromotor control.

SIGNIFICANCE

This bilateral teleoperation system enables novel prosthesis control and feedback strategies that could improve prosthesis control and aid motor learning.

Exercise as A Potential Therapeutic Target for Diabetic Cardiomyopathy: Insight into the Underlying Mechanisms

Diabetes mellitus is associated with cardiovascular, ophthalmic, and renal comorbidities. Among these, diabetic cardiomyopathy (DCM) causes the most severe symptoms and is considered to be a major health problem worldwide. Exercise is widely known as an effective strategy for the prevention and treatment of many chronic diseases. Importantly, the onset of complications arising due to diabetes can be delayed or even prevented by exercise. Regular exercise is reported to have positive effects on diabetes mellitus and the development of DCM. The protective effects of exercise include prevention of cardiac apoptosis, fibrosis, oxidative stress, and microvascular diseases, as well as improvement in cardiac mitochondrial function and calcium regulation. This review summarizes the recent scientific findings to describe the potential mechanisms by which exercise may prevent DCM and heart failure.

The feasibility and RE-AIM evaluation of the TAME health pilot study

Background

Conducting 5 A’s counseling in clinic and utilizing technology-based resources are recommended to promote physical activity but little is known about how to implement such an intervention. This investigation aimed to determine the feasibility and acceptability, using the RE-AIM (Reach, Effectiveness, Adoption, Implementation, Maintenance) framework, of a pragmatic, primary care-based intervention that incorporated 5 A’s counseling and self-control through an activity monitor.

Methods

Primary care patients (n = 40) 55–74 years of age were recruited and randomized to receive a pedometer or an electronic activity monitor (EAM), Jawbone UP24, to monitor activity for 12 weeks. Participants were also invited to a focus group after completing the intervention. Stakeholders (n = 36) were recruited to provide feedback.

Results

The intervention recruitment rate was 24.7%. The attrition rate was 20% with a significantly higher rate for the pedometer group (p = 0.02). The EAM group increased their minutes of physical activity by 11.1 min/day while the pedometer maintained their activity (0.2 min/day), with no significant group difference. EAM participants liked using their monitor and would continue wearing it while the pedometer group was neutral to these statements (p < 0.05). Over the 12 weeks there were 490 comments and 1094 “likes” given to study peers in the corresponding application for the UP24 monitor. Some EAM participants enjoyed the social interaction feature while others were uncomfortable talking to strangers. Participants stated they would want counseling from a counselor and not their physician or a nurse. Other notable comments included incorporating multiple health behaviors, more in-person counseling with a counselor, and having a funding source for sustainability.

Conclusions

Overall, the study was well-received but the results raise a number of considerations. Practitioners, counselors, and researchers should consider the following before implementing a similar intervention: 1) utilize PA counselors, 2) target multiple health behaviors, 3) form a social support group, 4) identify a funding source for sustainability, and 5) be mindful of concerns with technology.

Trial registration

clinicaltrials.gov- NCT02554435. Registered 24 August 2015.

Electronic supplementary material

The online version of this article (doi:10.1186/s12966-017-0560-5) contains supplementary material, which is available to authorized users.

Effects of an adapted cardiac rehabilitation programme on arterial stiffness in patients with type 2 diabetes without cardiac disease diagnosis

PURPOSE

To determine the effects of a 12-week cardiac rehabilitation programme of aerobic and resistance exercise training on arterial stiffness, peak calf vasodilatory reserve, and haemostatic markers in patients with type 2 diabetes.

METHODS

Observational cohort study examining effects of 12 weeks of exercise training in 23 subjects (13 men, 10 women; mean age of 56.1 ± 10.1 years) with type 2 diabetes mellitus. Subjects performed exercise training for 12 weeks [aerobic training 5 days/week, 70%-75% peak cardiovascular fitness (VO_2peak) and resistance training 2-3 days/week, 60% of one repetition maximum]. Vascular stiffness (pulse-wave velocity), augmentation index, peak calf vasodilatory reserve, and VO_2peak were measured pre- and post-exercise training. Secondary outcomes included heart rate variability and haemostatic measures.

RESULTS

VO_2peak increased by 16% (20.1 ± 5.5 vs 23.2 ± 8.8 mL/kg/min, p = 0.002) and abdominal circumference was reduced (101.9 ± 13.3 vs 97.9 ± 12.7 cm, p < 0.03). Vascular function was improved including central arterial stiffness (central pulse-wave velocity: 8.44 ± 1.75 vs 8.02 ± 1.60 m/s, p = 0.026) and the aortic augmentation index (21.7 ± 10.6% vs 18.3 ± 12.6%, p = 0.005); peak calf vasodilatory reserve increased from 30.3 ± 10.6 mL/100 mL/min to 38.0 ± 15.3 mL/100 mL/min ( p = 0.04). No changes were seen in heart rate variability, blood lipids, glycated haemoglobin and C-reactive protein.

CONCLUSION

A 12-week cardiac rehabilitation programme of aerobic and resistance training significantly reduces arterial stiffness and improves aerobic fitness in individuals with type 2 diabetes mellitus.

Testing Activity Monitors' Effect on Health: Study Protocol for a Randomized Controlled Trial Among Older Primary Care Patients

BACKGROUND

Cardiovascular disease is the leading cause of mortality in the United States. Maintaining healthy levels of physical activity is critical to cardiovascular health, but many older adults are inactive. There is a growing body of evidence linking low motivation and inactivity. Standard behavioral counseling techniques used within the primary care setting strive to increase motivation, but often do not emphasize the key component of self-control. The addition of electronic activity monitors (EAMs) to counseling protocols may provide more effective behavior change and increase overall motivation for exercise through interactive self-monitoring, feedback, and social support from other users.

OBJECTIVE

The objective of the study is to conduct a three month intervention trial that will test the feasibility of adding an EAM system to brief counseling within a primary care setting. Participants (n=40) will be randomized to receive evidence-based brief counseling plus either an EAM or a pedometer.

METHODS

Throughout the intervention, we will test its feasibility and acceptability, the change in primary outcomes (cardiovascular risk and physical activity), and the change in secondary outcomes (adherence, weight and body composition, health status, motivation, physical function, psychological feelings, and self-regulation). Upon completion of the intervention, we will also conduct focus groups with the participants and with primary care stakeholders.

RESULTS

The study started recruitment in October 2015 and is scheduled to be completed by October 2016.

CONCLUSIONS

This project will lay the groundwork and establish the infrastructure for intervention refinement and ultimately translation within the primary care setting in order to prevent cardiovascular disease on a population level.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02554435; https://clinicaltrials.gov/ct2/show/NCT02554435 (Archived by WebCite at http://www.webcitation/6fUlW5tdT).

Is cardiorespiratory fitness a determinant of cardiomyopathy in the setting of type 2 diabetes?

OBJECTIVE

The aim of this study was to determine whether high fitness attenuates the defects in left ventricular (LV) structure, function and triglyceride (TG) content in patients with type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

Patients (n = 74) with T2DM and ≥1 additional cardiac risk factor were recruited to participate in this cross-sectional study. Outcome measures of interest were LV structure and function by magnetic resonance imaging (MRI) and myocardial TG content by (1)H-magnetic resonance spectroscopy (MRS). The primary exposure variable was cardiorespiratory fitness defined by peak oxygen consumption scaled to fat-free mass (FFM; VO2peak-FFM).

RESULTS

Mean age was 53.5 years; 42.9% were women and mean glycosylated haemoglobin (HbA1c) was 8.0% with the mean duration of T2DM 8.2 years. VO2peak-FFM was crudely associated with both LV end systolic (r = 0.35, p = 0.002) and diastolic volumes (r = 0.32, p = 0.004), but not with ejection fraction (r = -0.15, p = 0.206), myocardial TG (r = -0.04, p = 0.734) or early diastolic peak filling rate (PFR; r = -0.01, p = 0.887). In multiple linear regression analyses, among measures of LV structure/function, VO2peak-FFM was independently associated only with LV end-diastolic volume (EDV) (β = 1.037, p = 0.038).

CONCLUSION

In individuals with T2DM at increased cardiovascular (CV) risk, cardiorespiratory fitness is not associated with LV morphology, function or myocardial TG content.

Effect of a short-term exercise program on glycemic control measured by fructosamine test in type 2 diabetes patients

BACKGROUND

Glycated hemoglobin (A1C) and Fasting Plasma Glucose (FPG) are the two monitoring blood glucose tests most frequently used. However, both methods are shown to be insensitive to detect glycemic variations in short duration periods. Therefore, we aimed to assess the effect of a short-term exercise program on glycemic levels measured by fructosamine concentrations in type 2 diabetes patients.

METHODS

Eight volunteers (51.1 ± 8.2 years) underwent a supervised exercise program during eight weeks (3 d.wk-1, 50-60% of VO2 peak for 30-60 minutes). The body composition, VO2 peak, A1C, FPG, fructosamine and capillary blood glucose (CBG) were evaluated. We used ANOVA - One Way for repeated measures followed by Tukey post-hoc test and paired t test. P values <0.05 were considered significant.

RESULTS

We found statistical differences on the concentrations of fructosamine, VO2 peak and CBG. However, A1C and FPG showed no statistical difference. Fructosamine declined by 15% (57 μmol/L) between the beginning and the end of the study. Individually, 50% of the sample reached the reference values for the normality in fructosamine test. VO2 peak increased by 14.8% (3.8 ml.kg-1.min-1) and CBG decreased on an average of 34.4% (69.3 mg/dL).

CONCLUSIONS

Fructosamine test is effective in the evaluation of glucose with type 2 diabetes patients when undergoing a short exercise program, alternatively to the traditional A1C and FPG assessment. Our results are relevant in clinical practice, because the significant improvement in glycemic status can help to evaluate the inclusion of exercise as adjunct therapy to replace the prescription of additional drugs in poorly controlled patients.

Exercise in the management of type 2 diabetes mellitus: what are the benefits and how does it work?

In this article, we examine the results from meta-analyses of studies that have focused on the effects of supervised exercise in patients with established type 2 diabetes mellitus. Exercise has been clearly demonstrated to have benefits on blood glucose control (average reduction of glycated hemoglobin, 0.6%) and cardiovascular risk factors. These benefits are observed independently of any change in body mass index and fat mass, and are also seen in older populations. Multiple mechanisms are involved, and the improved insulin-sensitizing effect of exercise training is not restricted to muscle but extends to hepatic and adipose tissue. However, while the benefits of exercise in type 2 diabetes management are undisputable, it is not as easy to draw correlations between clinical benefit and the amount of physical activity included in daily life. Recent studies have shown encouraging results with moderate increases in physical activity, which are feasible for most patients and are sufficient to induce sustained positive changes for 2 years. Thus, the benefits of structured and supervised exercise in patients with type 2 diabetes have been consistently demonstrated. Currently, the primary challenge is to determine how long-term increased physical activity can be durably implemented in a patient's daily life.

Importance of exercise immunology in health promotion

Chronic physical exercise with adequate intensity and volume associated with sufficient recovery promotes adaptations in several physiological systems. While intense and exhaustive exercise is considered an important immunosuppressor agent and increases the incidence of upper respiratory tract infections (URTI), moderate regular exercise has been associated with significant disease protection and is a complementary treatment of many chronic diseases. The effects of chronic exercise occur because physical training can induce several physiological, biochemical and psychological adaptations. More recently, the effect of acute exercise and training on the immunological system has been discussed, and many studies suggest the importance of the immune system in prevention and partial recovery in pathophysiological situations. Currently, there are two important hypotheses that may explain the effects of exercise and training on the immune system. These hypotheses including (1) the effect of exercise upon hormones and cytokines (2) because exercise can modulate glutamine concentration. In this review, we discuss the hypothesis that exercise may modulate immune functions and the importance of exercise immunology in respect to chronic illnesses, chronic heart failure, malnutrition and inflammation.

An Ecological Perspective on the Community Translation of Exercise Research for Older Adults

Regular exercise lowers the risk of disease progression for many chronic illnesses, but older adults experience relatively low rates of exercise. Although multiple intervention studies indicate that community-based programs can facilitate exercise participation, whether this research has resulted in widespread targeted exercise programs within communities is unknown. This study seeks to understand the ecological context of exercise for older adults through a cross-sectional survey of community exercise facilities within a mid-Atlantic city. The findings highlight the limited nature of the existing exercise infrastructure and reveal gaps in the community translation of research evidence regarding exercise adherence. An expansion in the availability of community exercise programs for older adults and more uniform policies to support older adult exercise are needed.

Effects of exercise training on physical impairment, arterial stiffness and health-related quality of life in patients with chronic kidney disease: a pilot study

BACKGROUND

Patients with chronic kidney disease (CKD) have impaired performance in physical tasks, lower health-related quality of life and high cardiovascular morbidity and mortality. Moderate intensity exercise has been shown to provide cardiovascular and metabolic benefits in healthy individuals and patients without CKD. Long-term exercise training is recommended as a vital component in the management of a number of chronic diseases. This randomized controlled pilot project examined the effects of exercise in predialysis CKD patients.

METHODS

Ten patients were randomized to 12 months of exercise (EX) and 10 to standard care (CT). We compared the difference between the two groups in physical impairment (VO(2peak) and endurance time [ET]), arterial stiffness (augmentation index [AI]) and health-related quality of life (EuroQol EQ-5D and Short Form-36 questionnaires) (all measured at baseline and 12 months).

RESULTS

The difference between EX and CT was statistically significant for VO(2peak) (3.59 ml O(2)/kg/min; 95% CI 0.92, 6.26; P = 0.01), ET (10.97 min; 95% CI 4.34, 17.59; P = 0.003) and AI (-11.7%; 95% CI -18.79, -4.61; P = 0.003). Clinically important changes were noted in EQ-5D and SF-36.

CONCLUSIONS

This study suggests that long-term exercise training improves physical impairment, arterial stiffness and health-related quality of life in patients with predialysis CKD. A larger randomized trial is required to examine the impact of exercise on markers of cardiovascular risk and quality of life in predialysis CKD patients.

Physical activity maintains aortic endothelium-dependent relaxation in the obese type 2 diabetic OLETF rat

We tested the hypothesis that physical activity can attenuate the temporal decline of ACh-induced endothelium-dependent relaxation during type 2 diabetes mellitus progression in the Otsuka Long-Evans Tokushima fatty (OLETF) rat. Sedentary OLETF rats exhibited decreased ACh-induced abdominal aortic endothelium-dependent relaxation from 13 to 20 wk of age (20-35%) and from 13 to 40 wk of age (35-50%). ACh-induced endothelium-dependent relaxation was maintained in the physically active OLETF group and control sedentary Long-Evans Tokushima Otsuka (LETO) group from 13 to 40 wk of age. Aortic pretreatment with N(G)-nitro-l-arginine (l-NNA), indomethacin (Indo), and l-NNA + Indo did not alter the temporal decline in ACh-induced endothelium-dependent relaxation. Temporal changes in the protein expression of SOD isoforms in the aortic endothelium or smooth muscle did not contribute to the temporal decline in ACh-induced endothelium-dependent relaxation in sedentary OLETF rats. A significant increase in the 40-wk-old sedentary LETO and physically active OLETF rat aortic phosphorylated endothelial nitric oxide (p-eNOS)-to-eNOS ratio was observed versus 13- and 20-wk-old rats in each group that was not seen in the 40- versus 13- and 20-wk-old sedentary OLETF rats. These results suggest that temporal changes in the antioxidant system, EDHF, and cycloxygenase metabolite production in sedentary OLETF rat aortas do not contribute to the temporal decline in sedentary OLETF rat aortic ACh-induced endothelium-dependent relaxation seen with type 2 diabetes mellitus progression. We also report that physical activity in conjunction with aging in the OLETF rat results in a temporal increase in the aortic endothelial p-eNOS-to-eNOS ratio that was not seen in sedentary OLETF rats. These results suggest that the sustained aortic ACh-induced endothelium-dependent relaxation in aged physically active OLETF rats may be the result of an increase in active aortic eNOS.

Reduced leg blood flow during submaximal exercise in type 2 diabetes

It is unclear whether impaired cardiac and/or vascular function contribute to exercise intolerance in patients with type 2 diabetes.

PURPOSE

Magnetic resonance imaging (MRI) was used to determine whether reductions in cardiac output and/or femoral arterial blood flow contribute to reduced aerobic capacity in patients with type 2 diabetes.

METHODS

Cardiac and femoral arterial blood flow MRI scans were performed at rest and during low-intensity leg exercise in eight patients with type 2 diabetes and 11 healthy individuals. Maximal aerobic capacity VO(2 max) and maximal oxygen pulse were also determined in all participants.

RESULTS

V O(2 max) was 20% lower and maximal oxygen pulse was 16% lower in patients with type 2 diabetes (P < 0.05), whereas maximal heart rate was the same between groups. Low-intensity exercise induced a 20% increase in heart rate and cardiac output as well as a 60-70% increase in femoral blood flow in both groups (P < 0.05). Femoral arterial blood flow indexed to thigh lean mass was reduced during exercise in patients with type 2 diabetes compared with healthy individuals. Stroke volume indexed to fat-free mass was lower in patients with type 2 diabetes, but greater heart rate allowed cardiac output to be maintained during submaximal exercise.

CONCLUSIONS

These findings suggest that impaired femoral arterial blood flow, an indirect marker of muscle perfusion, affects low-intensity exercise performance in patients with type 2 diabetes. However, because of lower exercising stroke volume, we propose that femoral arterial blood flow and, possibly, cardiac output, limit V O(2 max) in patients with type 2 diabetes.

Exercise training protects the renal circulation against high glucose challenge

It has been shown previously that high glucose causes direct and acute endothelial dysfunction in non-diabetic isolated rabbit kidney. This study assessed whether exercise training is able to maintain normal renal vascular endothelial function despite high glucose exposure. Animals were pen confined (SED) or treadmill trained over a 12-week period (ExT). Kidneys isolated from SED and ExT rabbits were continuously perfused ex vivo during 3 h with Krebs-Henseleit solutions containing normal (5.5 mm) or high (15 mm) concentrations of d-glucose. In the SED 5.5 group, acetylcholine (ACh) induced dose-related vasodilator responses, reaching the maximum of 41+/- 2% (n=10; P<0.05). In the kidneys perfused with high concentrations of glucose (SED 15), endothelium-dependent vasodilation was significantly blunted. Maximal relaxation in the presence of 15 mm glucose was of 19 +/- 2%, which was significantly different from the SED 5.5 group (41+/- 2%, n=10, P<0.01). In the ExT 5.5 group, ACh-induced vasodilation was significantly enhanced when compared with the SED 5.5 group, reaching the maximum of (52+/- 2%, n=10, P<0.05). Moreover, the exposure of the renal circulation of ExT animals to high glucose did not change endothelium-dependent vasodilation induced by ACh (46+/- 3%, n=6), when compared with the ExT 5.5 group. Finally, exercise training prevented the deleterious effects of high glucose on endothelial-dependent renal vasodilation (SED 15: 19+/- 2% vs. ExT 15: 46+/- 3%; P<0.05). It is concluded that exercise training protects the rabbit renal circulation against endothelial dysfunction elicited by acute exposure to moderately elevated glucose levels, corresponding to the postprandial glycemia of diabetes type 2 patients under treatment. The enhanced renal vasodilator reserve elicited by exercise training turns out to be a response that protects the kidney from the deleterious effects of glycemic peaks.