Imaging and modeling of acute pressure-induced changes of collagen and elastin microarchitectures in pig and human resistance arteries.

The impact of disease-related changes in the extracellular matrix (ECM) on the mechanical properties of human resistance arteries largely remains to be established. Resistance arteries from both pig and human parietal pericardium (PRA) display a different ECM microarchitecture compared with frequently used rodent mesenteric arteries. We hypothesized that the biaxial mechanics of PRA mirror pressure-induced changes in the ECM microarchitecture. This was tested using isolated pig PRA as a model system, integrating vital imaging, pressure myography, and mathematical modeling. Collagenase and elastase digestions were applied to evaluate the load-bearing roles of collagen and elastin, respectively. The incremental elastic modulus linearly related to the straightness of adventitial collagen fibers circumferentially and longitudinally (both R2 ≥ 0.99), whereas there was a nonlinear relationship to the internal elastic lamina elastin fiber branching angles. Mathematical modeling suggested a collagen recruitment strain (means ± SE) of 1.1 ± 0.2 circumferentially and 0.20 ± 0.01 longitudinally, corresponding to a pressure of ~40 mmHg, a finding supported by the vital imaging. The integrated method was tested on human PRA to confirm its validity. These showed limited circumferential distensibility and elongation and a collagen recruitment strain of 0.8 ± 0.1 circumferentially and 0.06 ± 0.02 longitudinally, reached at a distending pressure below 20 mmHg. This was confirmed by vital imaging showing negligible microarchitectural changes of elastin and collagen upon pressurization. In conclusion, we show here, for the first time in resistance arteries, a quantitative relationship between pressure-induced changes in the extracellular matrix and the arterial wall mechanics. The strength of the integrated methods invites for future detailed studies of microvascular pathologies.NEW & NOTEWORTHY This is the first study to quantitatively relate pressure-induced microstructural changes in resistance arteries to the mechanics of their wall. Principal findings using a pig model system were confirmed in human arteries. The combined methods provide a strong tool for future hypothesis-driven studies of microvascular pathologies.

Making sense of a new technology in clinical practice: a qualitative study of patient and physician perspectives.

BACKGROUND: The number of new technologies for risk assessment available in health care is increasing. These technologies are intended to contribute to both improved care practices and improved patient outcomes. To do so however, there is a need to study how new technologies are understood and interpreted by users in clinical practice. The objective of this study was to explore patient and physician perspectives on the usefulness of a new technology to detect Cardiovascular Autonomic Neuropathy (CAN) in a specialist diabetes clinic. The technology is a handheld device that measures resting heart rate and conducts three cardiac autonomic reflex tests to evaluate heart rate variability. METHODS: The study relied on three sources of data: observations of medical consultations where results of the CAN test were reported (n = 8); interviews with patients who had received the CAN test (n = 19); and interviews with physicians who reported results of the CAN test (n = 9). Data were collected at the specialist diabetes clinic between November 2013 and January 2014. Data were analysed using the concept of technological frames which is used to assess how physicians and patients understand and interpret the new technology. RESULTS: Physicians generally found it difficult to communicate test results to patients in terms that patients could understand and to translate results into meaningful implications for the treatment of patients. Results of the study indicate that patients did not recall having done the CAN test nor recall receiving the results. Furthermore, patients were generally unsure about the purpose of the CAN test and the implications of the results. DISCUSSION: Involving patients and physicians is essential when a new technology is introduced in clinical practice. This particularly includes the interpretation and communication processes related to its use. CONCLUSIONS: The integration of a new risk assessment technology into clinical practice can be accompanied by several challenges. It is suggested that more information about the CAN test be provided to patients and that a dialogue-based approach be used when communicating test results to patients in order to best support the use of the technology in clinical practice.

Diabetes Distress, Intentional Hyperglycemia at Work, and Glycemic Control Among Workers With Type 1 Diabetes.

OBJECTIVE: The aim was to explore relationships between work-related factors, work-related diabetes distress (WRDD), diabetes distress (measured by Problem Areas in Diabetes [PAID]-5 scale), intentional hyperglycemia at work (IHW), and glycemic control. RESEARCH DESIGN AND METHODS: A cross-sectional survey was conducted with 1,030 working adults with type 1 diabetes and linked with electronic health record data from a specialist diabetes clinic in Denmark. With use of structural equation modeling, two alternative models were compared, based on fit indices, statistical significance, and theoretical meaningfulness. RESULTS: A combined model provided the best fit to the data. WRDD was more strongly affected by work ability, opportunity to self-manage at work, being treated differently, and job demands. PAID-5 was more strongly affected by identity concern and blame and judgment. Both PAID-5 and WRDD were associated with more frequent IHW, which was associated in turn with worse glycemic control. CONCLUSIONS: Work-related factors are associated with WRDD and PAID-5. Distress increases the frequency of IHW, which is, in turn, associated with worse glycemic control. Future studies should investigate ways to balance diabetes management and work life without compromising diabetes care.

A call for inclusion of work-related diabetes distress in the spectrum of diabetes management: Results from a cross-sectional survey among working people with type 1 diabetes.

AIM: Diabetes distress captures a range of emotional responses and reactions to life with diabetes and is considered a part of the experience of managing diabetes and its treatment. Given the importance of the social context of work life for people of working age we set out to explore whether work-related diabetes distress is a distinct and important dimension of diabetes-related emotional distress in working people with type 1 diabetes. METHODS: A questionnaire with self-reported measures of psychosocial health and well-being at work was completed by 1126 working people with type 1 diabetes from a specialist diabetes clinic in Denmark. Work-related diabetes distress was assessed with two questions about worry and exhaustion related to reconciling work life and diabetes. Diabetes-related emotional distress was assessed with the Problem Areas in Diabetes scale (PAID-5), a short form version of the full PAID scale. We performed inter-item correlation analyses, exploratory factor analysis, and hierarchical multiple regression analyses. RESULTS: Inter-item correlations and exploratory factor analysis indicated that work-related diabetes distress was distinct from diabetes-related emotional distress. Further, work-related diabetes distress was found to be a unique contributor to work ability, quality of life, intentional hyperglycaemia at work, and absenteeism, after adjusting for covariates and diabetes-related emotional distress. CONCLUSIONS: The findings suggest that work-related diabetes distress captures an aspect of distress so far unaccounted for in workers with type 1 diabetes. Further studies are needed to strengthen the conceptual basis of work-related diabetes distress, explore its clinical usefulness and clarify its risk factors.