Effects of a comprehensive structured patient education intervention on disease-related knowledge and behaviour change among people living with type 2 diabetes in the Philippines.

Introduction: Addressing the ongoing needs of individuals with diabetes, particularly in low- and middle-income countries like the Philippines, requires a focus on regular follow-ups with healthcare teams, adherence to healthy behaviors, and effective patient education to prevent long-term complications. The aim of this study was to ascertain the impact of a comprehensive educational program for those living with diabetes in the Philippines. Methods: In a prospective study, a convenience sample of patients living with diabetes attending a cardiac rehabilitation or an outpatient diabetes clinic in the Philippines received a 12-week education intervention. Participants completed surveys at pre- and post-intervention assessing disease-related knowledge, health literacy, dietary habits, and tobacco use. Physical activity was measured by steps taken per day using wearable devices and by self-report of minutes of moderate or vigorous-intensity exercise per week. Satisfaction with the educational materials was also evaluated by a survey composed of Likert-type scale and open-ended questions. Descriptive statistics, paired t-tests or chi-square were used for data analysis. Results: Overall, 184 individuals living with diabetes type 2 (mean age = 54.4 ± 12.4, 32% female) completed both assessments. There was significant improvement in disease-related knowledge (p < 0.001), daily steps measured by a wearable device and self-reported minutes of moderate/vigorous-intensity exercise (p < 0.001), and the number of fruit and vegetable servings consumed per day (p = 0.001). No significant changes were observed in health literacy levels. One participant stopped using tobacco at post-education. Educational materials were highly satisfactory to participants. Lack of time, family responsibilities, and poor internet access were the main barriers to learning reported by participants. Suggestions to improve the education provided included assessment of information needs at the start of the education, having short summaries about the topics, follow-ups post-intervention, and inviting family members to sessions. Discussion: Results of this study demonstrated the positive effects a comprehensive structured patient education intervention on disease-related knowledge and behaviour changes among people living with type 2 diabetes in the Philippines.

Evidence-informed development of women-focused cardiac rehabilitation education.

BACKGROUND: Despite their differential risk factor burden, context and often different forms of heart disease, cardiac rehabilitation (CR) programs generally do not provide women with needed secondary prevention information specific to them. OBJECTIVE: to co-design evidence-informed, theory-based comprehensive women-focused education, building from Health e-University's Cardiac College for CR. METHODS: A multi-disciplinary, multi-stakeholder steering committee (N = 18) oversaw the four-phase development of the women-focused curriculum. Phase 1 involved a literature review on women's CR information needs and preferences, phase 2 a CR program needs assessment, phase 3 content development (including determining content and mode, assigning experts to create the content, plain language review and translation), and phase 4 will comprise evaluation and implementation. In phase 2, a focus group was conducted with Canadian CR providers; it was analyzed using Braun and Clarke's iterative approach. RESULTS: Nineteen providers participated in the focus group, with four themes emerging: current status of education, challenges to delivering women-focused education, delivery modes and topical resources. Results were consistent with those from our related global survey, supporting saturation of themes. Co-designed educational materials included 19 videos. These were organized across 5 webpages in English and French, specific to tests and treatments, exercise, diet, psychosocial well-being, and self-management. Twelve corresponding session slide decks with notes for clinicians were created, to support program delivery in CR flexibly. CONCLUSION: While further evaluation is underway, these open-access CR education resources will be disseminated for implementation, to support women in reducing their risk of cardiovascular sequelae.

A Systematic Review of Interventions With an Educational Component Aimed at Increasing Enrollment and Participation in Cardiac Rehabilitation.

OBJECTIVE: The aim of this study was to systematically review the impact and characteristics of interventions with an educational component designed to improve enrollment and participation in cardiac rehabilitation (CR) among patients with cardiovascular disease. REVIEW METHODS: Five electronic databases were searched from data inception to February 2023. Randomized controlled trials and controlled, cohort, and case-control studies were considered for inclusion. Title, abstract, and full text of records were screened by two independent reviewers. The quality of included studies was rated using the Mixed Methods Assessment Tool. Results were analyzed in accordance with the Synthesis Without Meta-analysis reporting guideline. RESULTS: From 7601 initial records, 13 studies were included, six of which were randomized controlled trials ("high" quality = 53%). Two studies evaluated interventions with an educational component for health care providers (multidisciplinary team) and 11 evaluated interventions for patient participants (n = 2678). These interventions were delivered in a hybrid (n = 6; 46%), in-person (n = 4; 30%), or virtual (n = 3; 23%) environment, mainly by nurses (n = 4; 30%) via discussion and orientation. Only three studies described the inclusion of printed or electronic materials (eg, pamphlets) to support the education. Eleven of 12 studies reported that patients who participated in interventions with an educational component or were cared for by health care providers who were educated about CR benefits (inhospital and/or after discharge) were more likely to enroll and participate in CR. CONCLUSION: Interventions with an educational component for patients or health care providers play an important role in increasing CR enrollment and participation and should be pursued. Studies investigating the effects of such interventions in people from ethnic minority groups and living in low-and-middle-income countries, as well as the development of standard educational materials are recommended.

Effectiveness of a virtual vs. in-person group-based education curriculum to increase disease-related knowledge and change health behaviour among cardiac rehabilitation participants.

OBJECTIVE: To investigate the effectiveness of a virtual 12-week group-based education curriculum and to compare results with a retrospective cohort that received the same education in-person for 24 weeks. METHODS: Participants completed online surveys (pre- and post-intervention) assessing disease-related knowledge, adherence to the Mediterranean diet, exercise self-efficacy, and satisfaction. The number of steps taken per day was recorded using a wearable device. Paired t tests and repeated measures ANOVA were used. A Bonferroni correction was applied(p < 0.01). RESULTS: 80 CR participants receiving virtual education completed both assessments. Following virtual education, participants significantly increased knowledge(p < 0.001), adherence to the Mediterranean diet(p < 0.001) and number of daily steps(p = 0.01). These results were similarly observed in the in-person education group(n = 80), with no significant differences between groups. Virtual education participants decreased their self-efficacy post-intervention(p < 0.001); in contrast, participants of the in-person education increased their exercise self-efficacy(p < 0.001). Overall,31% of virtual and 71% of in-person education participants reported being satisfied with the education delivery format. CONCLUSIONS: A virtual group-based education curriculum was effective at improving knowledge and changing behaviour. Similar results were observed in those that received in-person education. Tailoring virtual education interventions to support exercise self-efficacy is warranted. PRACTICE IMPLICATION: This study strengthens the evidence supporting virtual education in CR.

Information needs of women with breast cancer participating in cardiovascular rehabilitation: A mixed-methods study.

OBJECTIVE: To determine the information needs of women with a history of breast cancer attending a cardiovascular rehabilitation (CR) program. METHODS: A mixed-methods approach was used, including a cross-sectional online survey using an adapted version of the Toronto Information Needs Questionnaire Breast Cancer (TINQ-BC) and 7 virtual focus group sessions (n = 20). RESULTS: Overall, 50 responses were received. The TINQ-BC mean was 4.2 ± 0.5/5, with 34/42 items scoring higher than 4 (very important). The highest information needs were related to knowing if cancer is in their bodies or has come back, ways to prevent treatment side effects, and how the illness may affect their future. Participants identified their preferences for education delivery as discussion with peers/healthcare providers and lectures. The focus groups revealed six overarching themes: need for peer support, to make connections, and build relationships; comfort with and utility of technology; desire to learn about specific educational topics; preferences for education sessions; value of education; and value of exercise. CONCLUSIONS: These findings provided insight into the information needs of women with a history of breast cancer who participate in CR. PRACTICAL IMPLICATION: The care of these patients should be personalized based on these needs to support their adherence to the program.

Evaluating the effectiveness of a comprehensive patient education intervention in a hybrid model of cardiac rehabilitation: A pilot study.

Objective: To evaluate the effectiveness of a comprehensive educational intervention in a hybrid model of cardiac rehabilitation in Spain during the COVID-19 pandemic. Methods: In a prospective pretest-posttest pilot study a pooled sample of patients attending hybrid cardiac rehabilitation in Spain received a culturally-adapted education intervention for 6 weeks. Participants completed surveys at pre- and post-rehabilitation assessing disease-related knowledge, health literacy, adherence to the Mediterranean Diet and self-efficacy. Physical activity was measured by number of steps per day using wearable activity tracking devices. Satisfaction with the educational materials was also evaluated by a survey with a 10 point Likert-type scale and yes/no and open-ended questions. Results: Eighty-one(99%) participants completed both assessments. There was significant improvement in disease-related knowledge(p < 0.001), physical activity(p < 0.001), and adherence to the diet(p = 0.005) post-rehabilitation. The number of participants that were classified as having "high health literacy skills" increased by 17%. Post-rehabilitation knowledge was associated with education level (ß = 0.430; p = 0.001),pre-rehabilitation knowledge (ß = 0.510; p = 0.002), and high health literacy skills (ß = 0.489; p = 0.01). Educational materials were highly satisfactory to participants. Conclusion: Significant increases in disease-related knowledge and health behaviors in patients attending hybrid models of cardiac rehabilitation are encouraging results that support the value of implementing comprehensive educational initiatives to programs in Spain. Innovation: This work presents preliminary evidence of the effectiveness of the first comprehensive education intervention that is open access and culturally adapted to people living with cardiovascular disease in Spain.

Patient education for people living with diabetes in the Philippines: A scoping review of information needs, diabetes knowledge and effectiveness of educational interventions.

BACKGROUND AND AIMS: Despite the growing burden of diabetes in the Philippines, available evidence indicates that its care and control are far from optimal, including patient education. The aim of this scoping review was to synthesize information in the available literature to describe the state of science of patient education for people living with diabetes in the Philippines, specific to educational needs, diabetes knowledge, and effectiveness of educational interventions. METHODS: Medline, Embase, Emcare, CINAHL, Pubmed and American Psychological Association PsycInfo were searched from data inception through July 2021. Studies of any methodology (qualitative/quantitative/mixed methods), sample size, and language were eligible for inclusion. RESULTS: Of 2021 initial citations, 7 studies were included, with all being quantitative in design and with a median Critical Appraisal Skills Program score of 8/12. Information needs were described by one study and related to self-care abilities. Diabetes knowledge was measured in 6 studies and improved significantly after educational interventions. Overall, studies showed that educational interventions significantly impacted self-efficacy, anthropometric measures, hemoglobin A1c levels, utilization of care and routine programme and attitudes regarding their health. CONCLUSIONS: The findings highlight the importance of a comprehensive and culturally appropriate educational intervention for this population. Further research is needed to develop such intervention and assess its effectiveness to change behaviour, such as increasing physical activity.

A Social-Ecological Perspective of the Perceived Barriers and Facilitators to Virtual Education in Cardiac Rehabilitation: A MIXED-METHODS APPROACH.

PURPOSE: This study explored the perceived barriers and facilitators to participation in patients who did and did not attend virtual cardiac rehabilitation (CR) education sessions. METHODS: A mixed-methods approach was used. Virtual patient education was delivered during the coronavirus-19 pandemic. Phase 1 included a cross-sectional online survey completed by individuals who did and did not participate in these sessions. For phase 2, six virtual focus group sessions were conducted using the social-ecological framework to guide thematic analysis and interpretation of findings. RESULTS: Overall, 106 online surveys were completed; 60 (57%) attended Cardiac College Learn Online (CCLO) sessions only, one (1%) Women with Heart Online (WwHO) only, 21 (20%) attended both, and 24 (22%) did not attend virtual sessions. Half of the participants who attended virtual sessions viewed between one and four sessions. Most participants were from Canada (95%) and included the Toronto Rehabilitation Institute/Toronto Western Hospital centers (76%). Focus group findings revealed six overarching themes: Intrapersonal (mixed emotions/feelings; personal learning preferences); Interpersonal (desire for warmth of human contact and interaction); Institutional (the importance of external endorsement of sessions); and Environmental (technology; perceived facilitators and barriers). CONCLUSION: These findings highlight the unprecedented situation that patients and CR programs are facing during the pandemic. Virtual patient education may be more accessible, convenient, and responsive to the complex needs of these CR participants.

Establishing a process to translate and adapt health education materials for natives and immigrants: The case of Mandarin adaptations of cardiac rehabilitation education.

BACKGROUND: Cardiac rehabilitation (CR) is a proven model of secondary prevention in which patient education is a core component. OBJECTIVES: to translate and culturally-adapt CR patient education for Mandarin-speaking patients living in China as well as immigrants, and offer recommendation for best practices in adaptation for both. METHODS: these steps were undertaken in China and Canada: (1) preparation; (2) translation and adaptation; (3) review by healthcare providers based on PEMAT-P; (4) think-aloud review by patients; and (5) finalization. RESULTS: Two independent Mandarin translations were undertaken using best practices: one domestic (China) and one international (immigrants). Input by 23 experts instigated revisions. Experts rated the language and content as culturally-appropriate, and perceived the materials would benefit their patients. A revised version was then administered to 36 patients, based on which a few edits were made to optimize understandability. CONCLUSIONS: some important differences emerged between translations adapted for native versus immigrant settings.

Patient education program for Brazilians living with diabetes and prediabetes: findings from a development study.

BACKGROUND: Globally, the incidence of diabetes is increasing and strategies to reach a comprehensive approach of care are needed, including education in self-management. This is particularly true in low and middle-income countries where the number of people living with diabetes is higher than in the high-income ones. This article describes the development of a structured patient education program for Brazilians living with diabetes or prediabetes. METHODS: These steps were undertaken: 1) a 4-phase needs assessment (literature search of local diabetes guidelines, environmental scan, evaluation of information needs of patients identified by diabetes experts, and patient focus groups); and, 2) the translation and cultural adaptation of the patient guide (preparation, translation, back-translation, back-translation review, harmonization, and proofreading). RESULTS: Four of the seven guidelines identified include educational aspects of diabetes management. No structured education program was reported from the environmental scan. Regarding the information needs, 15 diabetes experts identified their patients' needs, who referred that they have high information needs for topics related to their health condition. Finally, results from six patient focus groups were clustered into six themes (self-management, physical activity, eating habits, diabetes medication, psychosocial being, and sleep), all embedded into the new education program. Constructive theory, adult learning principles, and the Health Action Process Approach model were used in program development and will be used in delivery. The developed program consists of 18 educational sessions strategically mapped and sequenced to support the program learning outcomes and a patient guide with 17 chapters organized into five sections, matched with weekly lectures. CONCLUSIONS: This program is a sequential and theoretical strategic intervention that can reach programs in Brazil to support diabetes and prediabetes patient education.

Development and Validation of the DiAbeTes Education Questionnaire (DATE-Q) to Measure Knowledge Among Diabetes and Prediabetes Patients Attending Cardiac Rehabilitation Programs.

PURPOSE: Knowledge assessment tools are highly useful in clinical practice, as they help health care teams to customize education and clinical care plans based on the needs of patients. The objective of this study was to develop and validate the DiAbeTes Education Questionnaire (DATE-Q) to measure knowledge among diabetes and prediabetes patients attending cardiac rehabilitation (CR). METHODS: Based on patient information needs, other validated tools and diabetes education standards and current practices, experts developed 20 items to comprise the first version of the DATE-Q. To establish content validity, they were reviewed by an expert panel (n = 12) and patients. Refined items were psychometrically tested in 84 diabetes and prediabetes patients attending CR. The internal consistency was assessed via regularized factor analysis and Cronbach α, and criterion validity with regard to patient education and family income. For interpretability analysis, the minimal clinically important difference (MCID) was estimated using distribution- and anchor-based methods. RESULTS: All items were appropriate for administration in this population according to experts and patients. Three factors were extracted and were generally internally consistent and well defined by the items. Criterion validity was supported by significant differences in mean scores by family income (P < .05). Results showed that increases in knowledge can moderately increase mean steps/d and peak oxygen uptake, with an MCID of 2.13. CONCLUSIONS: This study demonstrated preliminary validity of the DATE-Q. Future research is needed to assess other measurement properties to confirm the applicability of this tool in clinical and research settings.

Predictors of Exercise Maintenance 6 Months After Comprehensive Cardiac Rehabilitation.

PURPOSE: The objectives of this study were (1) to assess the effects of a comprehensive education intervention on maintenance of knowledge, exercise behavior, heart-healthy food intake, self-efficacy, and health literacy 6 mo after comprehensive cardiac rehabilitation (CR), and (2) to identify predictors of exercise maintenance 6 mo after comprehensive CR. METHODS: A prospective longitudinal study was conducted to test the effects of a structured educational curriculum in three CR programs in Canada. Participants completed surveys pre-, post-CR and 6 mo post-discharge to assess knowledge, heart-healthy food intake, self-efficacy, and health literacy. Exercise behavior was measured by number of steps/d using a pedometer. RESULTS: One hundred twenty participants completed the final survey. Increases in disease-related knowledge and self-efficacy, as well as behavior changes (increases in exercise and heart-healthy food intake), were achieved in comprehensive CR and sustained 6 mo post-program. Exercise maintenance was predicted by changes in heart-healthy food intake, self-efficacy, health literacy, and exercise-related knowledge. CONCLUSIONS: In this three-site study focusing on patient education for CR patients in Canada, the benefits of an education intervention in maintaining knowledge, exercise, healthy food intake, and self-efficacy were supported.

Effectiveness of an Education Intervention Among Cardiac Rehabilitation Patients in Canada: A Multi-Site Study.

BACKGROUND: Although patient education is considered a core component of cardiac rehabilitation (CR) programs, to our knowledge, no educational program designed for CR has been standardized in Canada. This absence of standardization may be due to a lack of reliable resources to educate these patients. The objective of this study was to assess the effectiveness of an education intervention in improving knowledge and health behaviours among CR patients in 3 sites in Canada. METHODS: CR patients were exposed to an evidence- and theoretically based comprehensive education intervention. Patients completed surveys assessing knowledge, physical activity, food intake, self-efficacy, and health literacy. All outcomes were assessed pre- and post-CR. Paired t tests were used to investigate variable changes between pre- and post-CR, Pearson correlation coefficients were used to determine the association between knowledge and behaviours, and linear regression models were computed to investigate differences in overall post-CR knowledge based on participant characteristics. RESULTS: A total of 252 patients consented to participate, of whom 158 (63.0%) completed post-CR assessments. There was a significant improvement in patients' overall knowledge pre- to post-CR, as well as in exercise, food intake, and self-efficacy (P < 0.05). Results showed a significant positive correlation between post-CR knowledge and food intake (r = 0.203; P = 0.01), self-efficacy (r = 0.201; P = 0.01), and health literacy (r = 0.241; P = 0.002). Education level (unstandardized beta = -2.511; P = 0.04) and pre-CR knowledge (unstandardized beta = 0.433; P < 0.001) were influential in changing post-CR knowledge. CONCLUSION: In this first-ever multi-site study focusing on patient education for CR patients in Canada, the benefits of an education intervention have been supported.

CONTEXTE: Bien que l'éducation du patient soit considérée comme un élément essentiel des programmes de réadaptation cardiaque (RC), il n'existe, à notre connaissance, aucun programme éducatif standardisé en RC au Canada. Cette absence de standardisation peut être attribuable à un manque de ressources fiables en matière d'éducation des patients. Cette étude visait à évaluer l'efficacité réelle d'une intervention éducative au regard de l'amélioration des connaissances et des comportements touchant la santé chez des patients en RC dans trois établissements au Canada. MÉTHODOLOGIE: Une intervention éducative globale fondée sur des données probantes et théoriques a été menée auprès de patients en RC. Les patients ont répondu à des questionnaires d'évaluation des connaissances, de l'activité physique, de l'apport alimentaire, de l'autoefficacité et de la littératie en matière de santé. Tous les résultats ont été évalués avant et après la RC. Des tests t pour échantillons appariés ont été utilisés pour étudier les changements touchant les variables évaluées avant et après la RC, des coefficients de corrélation de Pearson ont servi à déterminer l'association entre les connaissances et les comportements, et des modèles de régression linéaire ont été calculés pour étudier les différences dans les connaissances globales après la RC en fonction des caractéristiques des participants. RÉSULTATS: Au total, 252 patients ont accepté de participer; de ce nombre, 158 (63,0 %) ont pris part aux évaluations postérieures à la RC. Les connaissances globales des patients se sont améliorées de façon significative d'avant à après la RC, tout comme l'activité physique, l'apport alimentaire et l'autoefficacité (p < 0,05). Les résultats ont montré une corrélation positive significative entre les connaissances et l'apport alimentaire (r = 0,203; p = 0,01), l'autoefficacité (r = 0,201; p = 0,01) et la littératie en matière de santé (r = 0,241; p = 0,002) après la RC. Le niveau d'éducation (B = -2,511; p = 0,04) et les connaissances avant la RC (B = 0,433; p < 0,001) ont influé sur les changements touchant les connaissances après la RC. CONCLUSION: Cette toute première étude multicentrique axée sur l'éducation des patients en RC au Canada a permis de confirmer les avantages d'une intervention éducative.

Effectiveness of an education intervention associated with an exercise program in improving disease-related knowledge and health behaviours among diabetes patients.

OBJECTIVE: to assess the effectiveness of an education intervention associated with an exercise program in improving knowledge and health behaviours among diabetes patients. METHODS: Diabetes and prediabetes patients were exposed to an evidence- and theoretically-based comprehensive education intervention over 24 weeks. Patients completed surveys assessing knowledge, physical activity, food intake, self-efficacy, and health literacy. Functional capacity was measured by oxygen uptake. All outcomes were assessed pre- and post-CR. Satisfaction about the education provided was assessed at post-CR. Paired t-tests, Pearson correlation coefficients, and linear regression models were computed to investigate the effectiveness of this intervention. RESULTS: 84 patients consented to participate, of which 47(56.0%) completed post-CR assessments. There was a significant improvement in patients' overall knowledge pre- to post-CR, as well as in physical activity, food intake, self-efficacy, and health literacy (p < 0.05). Peak VO2 has clinically significant improved. Results showed a low significant positive correlation was between post-CR knowledge and food intake(r = 0.297;p = 0.04). Linear regression analysis revealed that age(B=-0.051; p = 0.01) was influential in changing post-CR knowledge. CONCLUSION: The benefits of an education intervention designed for diabetes and prediabetes patients associated with an exercise program have been supported. PRACTICE IMPLICATIONS: This work shows one effective education strategy taken in place that can be replicated in different settings.

Validation of a self-administered version of the Mediterranean diet scale (MDS) for cardiac rehabilitation patients in Canada.

The Mediterranean dietary pattern has been linked with lower incidence of cardiovascular disease and the Mediterranean diet scale (MDS) has been created to incorporate and test the inherent characteristics of this dietary pattern. This study aimed to psychometrically validate a self-administered version of the MDS in cardiac rehabilitation (CR) patients in Canada. To establish content validity, the scale was reviewed by an expert interdisciplinary panel. A final version of the tool was tested in 150 CR patients. Cronbach's alpha was 0.69. All ICC coefficients met the minimum recommended standard. Factor analysis revealed four factors, all internally consistent. Criterion validity was supported by significant differences in total scores by duration in CR. Construct validity was supported by agreements between the self-administered MDS and original MDS in all items and with the 3-day food record in 8 of 13 items. In conclusion, the self-administered version of the MDS demonstrated good reliability and validity.

Vascular biology of angiotensin and the impact of physical activity.

The renin-angiotensin system (RAS) is important for regulating blood pressure and extracellular fluid. The concept of the RAS has recently evolved from a classical systemic endocrine system to an appreciation of local RASs functioning in a paracrine manner, including in the vascular wall. Angiotensin II (AII), the main effector of the RAS, is a potent vasoconstrictor formed by the action of angiotensin-converting enzyme (ACE). ACE is multifunctional and also destroys the endogenous vasodilator bradykinin. A recently discovered novel ACE2 enzyme is responsible for forming a vasodilatory compound, angiotensin 1-7, from AII. Thus, the actions of ACE and ACE2 are antagonistic. Tissue actions of AII are mediated by specific receptors, AT1 and AT2, with AT1 mediating the classical actions. AT1-stimulated vasoconstricton occurs via phospholipase-D-mediated second messenger generation directly, and indirectly via the coupling of AT1 to the prooxidant enzyme NADPH oxidase. Since the vascular NADPH oxidase is a major source of vascular reactive oxygen species generation and is responsible for the breakdown of the vasodilator nitric oxide (NO), there is another potential link between RAS and regulation of vasodilatory pathways. AT2 signaling is antagonistic to AT1 signaling, and results in bradykinin and NO formation. Chronic AII signaling induces vascular dysfunction, whereas pharmacological management of the RAS can not only control blood pressure, but also correct endothelial dysfunction in hypertensives. Exercise training can also improve endothelial function in hypertensives, raising the question of whether there is a potential role for RAS in mediating the vascular effects of exercise training. Recent studies have demonstrated reductions in the expression of NADPH oxidase components in the vascular wall in response to exercise training, thus tempering one of the main cellular effectors of AII, and this is associated with reduced vascular ROS production and enhanced NO bioavailability. Importantly, it has now been demonstrated in human arteries that exercise training also tempers vascular AT1 receptor expression and AII-induced vasoconstriction, while enhancing endothelium-dependent dilation. The signals responsible for these chronic adaptations are not clearly understood, and may include changes in RAS components prompted by acute exercise. ACE genotype may have an effect on physical activity levels and on the cardiovascular responses to exercise training, and the II genotype (compared with ID and DD) is associated with the largest endothelium-dependent dilations in athletes compared with those in sedentary individuals. Thus, the tissue location of the RAS, the complement of ACE/ACE2, the receptor expression of AT1/AT2, and the ACE genotype are all variables that could impact the vascular responses to exercise training, but the responses of most of these variables to regular exercise training and the mechanisms responsible have not been systematically studied.

The influence of static axial torque in combined loading on intervertebral joint failure mechanics using a porcine model.

BACKGROUND: The spine is routinely subjected to repetitive combined loading, including axial torque. Repetitive flexion-extension motions with low magnitude compressive forces have been shown to be an effective mechanism for causing disc herniations. The addition of axial torque to the efficacy of failure mechanisms, such as disc herniation, need to be quantified. The purpose of this study was to determine the role of static axial torque on the failure mechanics of the intervertebral joint under repetitive combined loading. METHODS: Repetitive flexion-extension motions combined with 1472 N of compression were applied to two groups of nine porcine motion segments. Five Nm of axial torque was applied to one group. Load-displacement behaviour was quantified, and planar radiography was used to document tracking of the nucleus pulposus and to identify fractures. FINDINGS: The occurrence of facet fractures was found to be higher (P=0.028) in the axial torque group (7/9), compared to the no axial torque group (2/9). More hysteresis energy was lost up to 3000 cycles of loading in the axial torque group (P<0.014). The flexion-extension cycle stiffness was not different between the two groups until 4000 cycles of loading, after which the axial torque group stiffness increased (P=0.016). The percentage of specimens that herniated after 3000 cycles of loading was significantly larger (P=0.049) for the axial torque group (71%) compared to the no axial torque group (29%). INTERPRETATION: Small magnitudes of static axial torque alter the failure mechanics of the intervertebral disc and vertebrae in combined loading situations. Axial torque appears to accelerate the susceptibility for injury to the intervertebral joint complex. This suggests tasks involving axial torque with other types of loading, apart from axial twist motion, should be monitored to assess exposure and injury risk.

The direction of progressive herniation in porcine spine motion segments is influenced by the orientation of the bending axis.

BACKGROUND: It has been shown that disc herniations are a cumulative injury created by repetitive flexion motion while under modest compressive loads. There is a lack of data linking the direction of nucleus tracking to the orientation of the bending motion axis. Our purpose was to determine if the direction that the nucleus tracks through the annulus during progressive herniation is predictable from the direction of bending motion (i.e. a specific side with posterio-lateral herniation). METHODS: Matched cohorts (nu=16) of porcine cervical spine (C3/4 and C5/6) motion segments were potted in aluminum cups and bent at an angle of 30 degrees to the sagittal plane flexion axis while under a sustained compressive load of 1472 N. FINDINGS: The direction of bending motion affected the tracking pattern of the nucleus through the annular fibres in a predictable pattern. Specifically, bending the motion segments at an angle of 30 degrees to the left of the sagittal plane flexion axis biased the movement of the nucleus toward the posterior right side of the disc in 15 of the 16 specimens. INTERPRETATION: Based on this animal model, shown to have similar biomechanical behaviour to humans, the direction that the nucleus tracks through the annular fibres appears to be dependent upon the direction of bending motion. This may have implications on both herniation prevention and rehabilitation of posterio-lateral bulges and herniations.

The effect of static torsion on the compressive strength of the spine: an in vitro analysis using a porcine spine model.

STUDY DESIGN: Matched porcine cervical spine motion segments were subjected to two main conditions and compared: axial compression and axial compression combined with varying axial torque. OBJECTIVES: To determine the effect of torsion on the acute compressive strength of the spine. SUMMARY OF BACKGROUND DATA: The spine is often subjected to compression together with axial torque as a component of complex loading, yet there is a lack of documentation on its effect on the compressive strength and injury mechanics. METHODS: Matched cohorts of porcine cervical spine (C5-C6) motion segments were compressed to failure at a rate of 3,000 N/s combined with 0 Nm, 5 Nm, 20 Nm, or 30 Nm of axial torque. Three "failure" points were recorded from the stress/strain association: the first "step" (initial microfracture), the initial slope change (yield point or "slow crush" mechanism), and the ultimate failure point (fracture). Furthermore, resultant injuries were documented using planar radiography and visual inspection following dissection of the motion segments. RESULTS: Axial torque affected the failure characteristics during acute compressive loading. The ultimate strength of the motion segments was significantly reduced with increasing static torques. The compressive load at which initial microfracture occurred, indicated by the first "step" in the load-deformation curve, was increased with 5 Nm, 10 Nm, and 20 Nm of applied torsion in comparison to no torque, but this effect was reduced with 30 Nm of torque. The "slow crush" mechanism of failure was not affected by the addition of axial torque. No radiographic gross injuries to the facet joints were observed. Damage appeared to be confined to the endplate and trabecular network of the vertebral body. CONCLUSIONS: Based on this animal model, shown to have similar biomechanical behavior to humans, axial torque appears to significantly reduce the compressive strength of the spine.