Russell W. Jones

Adiposity Is Associated with Blunted Cardiovascular, Neuroendocrine and Cognitive Responses to Acute Mental Stress

Obesity and mental stress are potent risk factors for cardiovascular disease but their relationship with each other is unclear. Resilience to stress may differ according to adiposity. Early studies that addressed this are difficult to interpret due to conflicting findings and limited methods. Recent advances in assessment of cardiovascular stress responses and of fat distribution allow accurate assessment of associations between adiposity and stress responsiveness. We measured responses to the Montreal Imaging Stress Task in healthy men (N = 43) and women (N = 45) with a wide range of BMIs. Heart rate (HR) and blood pressure (BP) measures were used with novel magnetic resonance measures of stroke volume (SV), cardiac output (CO), total peripheral resistance (TPR) and arterial compliance to assess cardiovascular responses. Salivary cortisol and the number and speed of answers to mathematics problems in the task were used to assess neuroendocrine and cognitive responses, respectively. Visceral and subcutaneous fat was measured using T2 *-IDEAL. Greater BMI was associated with generalised blunting of cardiovascular (HR:β = −0.50 bpm.unit−1, P = 0.009; SV:β = −0.33 mL.unit−1, P = 0.01; CO:β = −61 mL.min−1.unit−1, P = 0.002; systolic BP:β = −0.41 mmHg.unit−1, P = 0.01; TPR:β = 0.11 WU.unit−1, P = 0.02), cognitive (correct answers: r = −0.28, P = 0.01; time to answer: r = 0.26, P = 0.02) and endocrine responses (cortisol: r = −0.25, P = 0.04) to stress. These associations were largely determined by visceral adiposity except for those related to cognitive performance, which were determined by both visceral and subcutaneous adiposity. Our findings suggest that adiposity is associated with centrally reduced stress responsiveness. Although this may mitigate some long-term health risks of stress responsiveness, reduced performance under stress may be a more immediate negative consequence.

Evaluation of the practical feasibility and acceptability of home monitoring in residential homes.

Three residential homes to the north-west of London, with their associated medical centres, were equipped with telemonitors to measure several variables, including seven-lead electrocardiogram, blood pressure, oxygen saturation, heart rate, temperature and respiration. The monitors could be operated by non-medical personnel. After recording, the data were transmitted via the Internet to a server. A total of 24 patients with a variety of chronic conditions were monitored regularly for a period of one year. Data transmission was found to be unreliable on occasions and was improved by extending the wireless network in the homes. Data access and presentation were considered acceptable, although suggestions for minor changes were made. No discernible impact on disease management, diagnosis or care was observed as a result of the monitoring. However, interviewees saw several potential benefits and patient acceptance was very good. The monitoring was found to be generally acceptable and feasibility was considered to have been largely proven.

Telemedicine and its role in improving communication in healthcare

Information and communication technology (ICT) plays an increasingly important role in delivering healthcare today. Healthcare professionals, including consultants, doctors and nurses, are engaged in what is seen as a radical action plan for improving the National Health Service (NHS) in the UK. A major focus of this plan is the greater empowerment of the patient, and providing them with more information about their health needs and care. Information and communication technology has the potential to effectively support the complexities involved in the communication that takes place both amongst healthcare workers themselves and between healthcare workers and their patients in both primary and secondary care both in the UK and elsewhere. This paper explores the challenges involved in human interaction and describes how AIDMAN, a clinical information system, allows for richer communication between the patient and those involved in their health.

Optimum delivery of telemedicine over low bandwidth satellite links

Telemedicine is frequently used to support the delivery of medicine to remote regions, but it can often be the case that these areas are poorly served by communications. The AIDMAN project investigates the delivery of telemedicine in remote regions of Greece using satellite. However the high cost of such links can severely limit the bandwidth available to applications. In addition the satellite link is a clear channel and may be configured to emulate any protocol. This presents a problem of determining which protocol may best support the applications. We have modelled the. three types of link protocol, circuit switched (ISDN), packet switched (TCP/IP) and cell switched (ATM) to determine how their characteristics affect the performance when bandwidth is severely restricted. We further investigate how performance may be optimised when the link is used to carry mixed traffic of real-time video conference and image transfer. Our simulation shows that TCP/IP can support telemedicine applications reasonably well, so long as the number of simultaneous image transfers are restricted. Furthermore, 1Pv6, which supports prioritisation of traffic, can overcome this restriction. Use of TCP/IP has further advantage, in that it permits integration of wider networks, is cheap, widely available and supports virtually all telemedicine applications. Real-time measurements using the virtual consultation workstations developed for the AIDMAN project on a low bandwidth link Implemented on routers connected using ISDN to simulate a link with 128 kbps and on the GALENOS satellite network confirms the findings of the simulation.

Habitual alcohol consumption is associated with lower cardiovascular stress responses – a novel explanation for the known cardiovascular benefits of alcohol?

Abstract In contrast to heavy alcohol consumption, which is harmful, light to moderate drinking has been linked to reduced cardiovascular morbidity and mortality. Effects on lipid status or clotting do not fully explain these benefits. Exaggerated cardiovascular responses to mental stress are detrimental to cardiovascular health. We hypothesized that habitual alcohol consumption might reduce these responses, with potential benefits. Advanced magnetic resonance techniques were used to accurately measure cardiovascular responses to an acute mental stressor (Montreal Imaging Stress Task) in 88 healthy adults (∼1:1 male:female). Salivary cortisol and task performance measures were used to assess endocrine and cognitive responses. Habitual alcohol consumption and confounding factors were assessed by questionnaire. Alcohol consumption was inversely related to responses of heart rate (HR) (r = −0.31, p = 0.01), cardiac output (CO) (r = −0.32, p = 0.01), vascular resistance (r = 0.25, p = 0.04) and mean blood pressure (r = −0.31, p = 0.01) provoked by stress, but not to stroke volume (SV), or arterial compliance changes. However, high alcohol consumers had greater cortisol stress responses, compared to moderate consumers (3.5 versus 0.7 nmol/L, p = 0.04). Cognitive measures did not differ. Findings were not explained by variations in age, sex, social class, ethnicity, physical activity, adrenocortical activity, adiposity, smoking, menstrual phase and chronic stress. Habitual alcohol consumption is associated with reduced cardiac responsiveness during mental stress, which has been linked to lower risk of hypertension and vascular disease. Consistent with established evidence, our findings suggest a mechanism by which moderate alcohol consumption might reduce cardiovascular disease, but not high consumption, where effects such as greater cortisol stress responses may negate any benefits.

Early experience in using telemonitoring for the management of chronic disease in primary care

Summary We have investigated the use of telemonitoring in three long-term conditions: chronic heart failure (CHF), type 2 diabetes and essential hypertension. Participants were provided with a home telemonitoring unit for a 12-week period and entered physiological data each day. The data were sent automatically via the participants telephone line to a server and could be viewed via a web browser. An intervention algorithm was developed to improve the accuracy with which patients requiring intervention were recognized compared to existing systems based on a simple threshold. Thirty patients completed the 12-week trial. One patient dropped out, giving data on 29 patients (mean age 70 years, 17 women). The algorithm prompted a clinical intervention in 11 patients (38%). The average time that elapsed before the first intervention was 47 days (SD 21). Primarily the interventions (72%) resulted in changes to medication and health advice. The results suggest that four weeks is sufficient time in which to recognize the need to intervene clinically and that in 12 weeks it is possible to effect a change towards a target.

Development and validation of risk assessment models for diabetes-related complications based on the DCCT/EDIC data

AIM To derive and validate a set of computational models able to assess the risk of developing complications and experiencing adverse events for patients with diabetes. The models are developed on data from the Diabetes Control and Complications Trial (DCCT) and the Epidemiology of Diabetes Interventions and Complications (EDIC) studies, and are validated on an external, retrospectively collected cohort. METHODS We selected fifty-one clinical parameters measured at baseline during the DCCT as potential risk factors for the following adverse outcomes: Cardiovascular Diseases (CVD), Hypoglycemia, Ketoacidosis, Microalbuminuria, Proteinuria, Neuropathy and Retinopathy. For each outcome we applied a data-mining analysis protocol in order to identify the best-performing signature, i.e., the smallest set of clinical parameters that, considered jointly, are maximally predictive for the selected outcome. The predictive models built on the selected signatures underwent both an interval validation on the DCCT/EDIC data and an external validation on a retrospective cohort of 393 diabetes patients (49 Type I and 344 Type II) from the Chorleywood Medical Center, UK. RESULTS The selected predictive signatures contain five to fifteen risk factors, depending on the specific outcome. Internal validation performances, as measured by the Concordance Index (CI), range from 0.62 to 0.83, indicating good predictive power. The models achieved comparable performances for the Type I and, quite surprisingly, Type II external cohort. CONCLUSIONS Data-mining analyses of the DCCT/EDIC data allow the identification of accurate predictive models for diabetes-related complications. We also present initial evidences that these models can be applied on a more recent, European population.

A Telemonitoring Architecture to Support Chronic Disease Management and Acute Episode Monitoring

We describe a telemonitoring architecture designed to support the dual role of chronic disease management and acute episode monitoring. In the former, measurements of parameters such as weight and blood pressure are taken periodically and are used to determine a change in the condition of a patient and thus prompt intervention in therapy. However, such patients can deteriorate rapidly and enter a phase where constant monitoring of vital signs is required. In these conditions, our system monitors ECG, SpO2 and temperature continuously and transmits data on preset events or at preset times. To date such monitoring has required two systems; we have developed a single system to fulfil both roles. Transmission and control protocol are designed along principles of the 11073 standard. We show how such monitoring can manage patients with acute conditions such as unstable angina and heart failure

Human and organisational aspects of remote patient monitoring in residential care homes

Demographic changes in the population, with a growing proportion of elderly people, make the efficient and effective provision of healthcare for this age group an increasingly important issue. We examine the organisational and human aspects of introducing a Remote Patient Monitoring (RPM) system that uses wireless and broadband networks into three residential care homes in the UK. Stakeholders were identified, and semi-structured one-to-one interviews were carried out in order to identify issues deemed most important to each group. The work is novel, as it requires examination of the issues of communication between healthcare workers in several primary and secondary care organisations. The key finding was the need to identify the changes in working practice and interpersonal communication. A key factor in particular was the change in relationships: staff in the remote centre needing to learn to seek support when reporting and requesting assistance for a problem; and for the staff at the health centres to respond appropriately.

Optimum Design for Teleconsultation Systems

We analyse the clinical process of patient referral developed and in routine use for over 5 year at Chorleywood Health Centre, UK. The system combines diagnostics performed in primary care with results forwarded to the consultant in electronic form. Patients may then be referred for teleconsultation between patient and local health care professional and distant consultant. By ensuring diagnostic information is gained in advance, we have determined that the teleconsultation may concentrate on management, and as a result is more efficient and effective. We further analyse the processes and determine the functional characteristics of the teleconsultation and the functional requirements of the teleconsultation system that may support the process in an optimum way