Is in-Shoe Microclimate a Neglected Contributor in the Pathway to Diabetic Foot Ulceration?

The identification of the key contributing factors which predispose the foot to ulceration, increasing the risk of recurrence and slow wound healing in diabetes mellitus (DM), has led to some significant research studies over the last 30 years, providing valuable insight into the mechanism leading to diabetic foot ulceration (DFU). Although, these contributory factors are similar to those identified in pressure ulceration occurring in other parts of the body (such as "bed pressure sores') where magnitude and/or duration of mechanical stress in the presence of sensory deficits are key causal factors, research investigating pressure ulceration has also included measurement of temperature and relative humidity at the interface between the skin and supporting surface. The possible influence of these parameters (in-shoe temperature and humidity) does not appear frequently in diabetic foot ulceration research. Referred to as "microclimate", this has an important role in the pathway to tissue breakdown evidenced in pressure ulcer research and may be particularly relevant in countries with warm and humid climates. As the microclimate is influential in the ulceration pathway for other body sites, its role in the DFU causal pathway justifies further investigation.

Modelling soil erosion responses to climate change in three catchments of Great Britain.

Simulations of 21st century climate change for Great Britain predict increased seasonal precipitation that may lead to widespread soil loss by increasing surface runoff. Land use and different vegetation cover can respond differently to this scenario, mitigating or enhancing soil erosion. Here, by means of a sensitivity analysis of the PESERA soil erosion model, we test the potential for climate and vegetation to impact soil loss by surface-runoff to three differentiated British catchments. First, to understand general behaviours, we modelled soil erosion adopting regular increments for rainfall and temperature from the baseline values (1961-1990). Then, we tested future climate scenarios adopting projections from UKCP09 (UK Climate Projections) under the IPCC (Intergovernmental Panel on Climate Change) on a defined medium CO2 emissions scenario, SRES-A1B (Nakicenovic et al., 2000), at the horizons 2010-39, 2040-69 and 2070-99. Our results indicate that the model reacts to the changes of the climatic parameters and the three catchments respond differently depending on their land use arrangement. Increases in rainfall produce a rise in soil erosion while higher temperatures tend to lower the process because of the mitigating action of the vegetation. Even under a significantly wetter climate, warmer air temperatures can limit soil erosion by enhancing primary productivity and in turn improving leaf interception, infiltration-capacity, and reducing soil erodibility. Consequently, for specific land uses, the increase in air temperature associated with climate change can modify the rainfall thresholds to generate soil loss, and soil erosion rates could decline by up to about 33% from 2070 to 2099. We deduce that enhanced primary productivity due to climate change can introduce a negative-feedback mechanism limiting soil loss by surface runoff as vegetation-induced impacts on soil hydrology and erodibility offset the effects of increased precipitation. The expansion of permanent vegetation cover could provide an adaptation strategy to reduce climate-driven soil loss.

A Novel Method to Determine Dynamic Temperature Trends Applied to In-Shoe Temperature Data During Walking.

Body temperature is one of the fundamental measures considered in the assessment of health and well-being, with various medical conditions known to give rise to abnormal changes in temperature. In particular, abnormal variations in dynamic temperature patterns during walking or exercise may be linked to a range of foot problems, which are of particular concern in diabetic patients.A number of studies have investigated normative temperature patterns of a population by considering data from multiple participants and averaging results after an acclimatisation interval. In this work we demonstrate that the temperature patterns obtained using such an approach may not be truly representative of temperature changes in a population, and the averaging process adopted may yield skewed results.An alternative approach to determine generic reference temperature patterns based on a minimization of root mean square differences between time-shifted versions of temperature data collected from multiple participants is proposed. The results obtained indicate that this approach can yield a general trend that is more representative of actual temperature changes across a population than conventional averaging methods. The method we propose is also shown to better capture and link the effects of factors that influence dynamic temperature trends, which could in turn lead to a better understanding of underlying physiological phenomena.

Identifying patient-reported outcomes in rheumatoid arthritis: the impact of foot symptoms on self-perceived quality of life.

BACKGROUND: The importance of patient-reported outcome measures in healthcare is increasingly recognized but these need to be patient generated. Given that foot symptoms are very common in rheumatoid arthritis (RA), we chose a patient-centred model with which to investigate the patients' perspective on how their foot symptoms affected them as individuals and impacted on their self-perceived quality of life, rather than using the traditional approaches of clinical examination (e.g. prevalence of deformities) or radiological assessments. METHODS: A 33-item self-administered postal questionnaire was sent to all people with RA attending outpatient clinics in three hospitals over the course of one month (n=390). The questionnaire used both quantitative and qualitative approaches to enquire about the nature and extent of foot complaints and how respondents believed this affected their quality of life. RESULTS: In total, 190 usable replies were received (49%). Nearly all respondents (n=177; 93.2%) reported that their quality of life was adversely affected by their foot complaint(s), with over half describing their quality of life as being badly or very badly affected. When asked to rate how severely foot complaints affected their quality of life using a 10 cm visual analogue scale, the mean score was 5.36 (range 0-10 ± SD 3), indicating that foot complaints have a moderate-to-severe effect on quality of life. Those aspects of daily living most significantly affected were: the ability to walk and the ability to wear a variety of shoes. CONCLUSION: This study demonstrated that people with RA focus on different aspects of the impact of their disease to doctors. Rather than foot deformity or ulceration, disease activity score or health assessment questionnaire score, patients were easily able to pinpoint the key negativities of living with RA in their feet and indicated choice of footwear and ability to walk as crucial. This study and similar ones are key to identifying appropriate patient-reported outcome measures.

Comparison of foot pain and foot care among rheumatoid arthritis patients taking and not taking anti-TNFα therapy: an epidemiological study.

Epidemiological studies report foot pain affects more than 90% of people with rheumatoid arthritis (RA). Most data about foot involvement in RA were collected prior to the availability of novel treatments such as biologics. The objective of this study is to compare the prevalence of foot symptoms, frequency of foot examination, and access to foot care services among RA patients currently treated with anti-TNFα to those not receiving biologics. This study is a cross-sectional epidemiological study: a 28-item self-administered questionnaire was posted to 1,040 people with RA throughout the UK. Overall, 585 (55%) useable replies were received, and 120 (20.5%) respondents were currently taking anti-TNFα medication. Prevalence of current foot pain was 99% among the biologics group compared with 76% not treated with biologics. Stiffness, swelling, and numbness in the feet were all significantly more common in the anti-TNFα group (P < 0.05). Most respondents (90%) taking biologics discussed their foot pain with their rheumatologist, but only 70% were receiving podiatry (compared to 78% not taking anti-TNFα). Subjects reported that their feet were examined significantly less frequently (P < 0.001) than their hands. Foot complaints are common in this group, and allied health professions could enhance rheumatological care by undertaking foot assessment.

Foot ulceration in diabetic patients.

Foot care is very important if patients with diabetes are to avoid ulceration complications. Kate Springett explains the importance of educating the patient to be aware of signs and symptoms of foot ulceration, and outlines the best management techniques within the scope of a multiprofessional care team.

Ultrasound assessment of skin and wound tissue: comparison with histology.

BACKGROUND/AIMS: Ultrasound is a valuable technique in dermatological assessment as it is non-invasive. This is particularly attractive for monitoring and evaluating wound healing. However, there is a limited literature on the use of ultrasound in monitoring wound healing. METHODS: In this study, the structures of skin (human and porcine) and healing wounds (porcine) were visualised using ultrasound (20 MHz) and compared with histology from the same site. Measurements of various features were undertaken using both ultrasound and histometric techniques and the results from each compared. Hydroxyproline levels were also measured and correlated with ultrasound measurement of granulation tissue. RESULTS: The echogenic characteristics of tissues are described. There was excellent correlation (r=0.96, P > 0.0001) between the ultrasound measurements and histology for porcine and human cadaver measurements. Ultrasound and histology measurements of acute porcine wounds also correlated well (r=0.96,P<0.0001). Comparison of hydroxyproline analysis with ultrasound measurements of fibrous granulation tissue (r=0.82,P > 0.001) indicates that ultrasound may be used to visualise accumulation of this tissue in wounds. CONCLUSIONS: Ultrasonography has been shown to be a useful, reliable, quantifiable technique for the assessment of wound healing.