In Vivo Experimental Study of Noninvasive Insulin Microinjection through Hollow Si Microneedle Array.

An experimental study of in vivo insulin delivery through microinjection by using hollow silicon microneedle array is presented. A case study was carried out on a healthy human subject in vivo to determine the influence of delivery parameters on drug transfer efficiency. As a microinjection device, a hollow microneedle array (13 × 13 mm²) having 100 microneedles (220 µm high, 130 µm-outer diameter and 50 µm-inner diameter) was designed and fabricated using classical microfabrication techniques. The efficiency of the delivery process was first characterized using methylene blue and a saline solution. Based on these results, the transfer efficiency was found to be predominantly limited by the inability of viable epidermis to absorb and allow higher drug transport toward the capillary-rich region. Two types of fast-acting insulin were used to provide evidence of efficient delivery by hollow MNA to a human subject. By performing blood analyses, infusion of more-concentrated insulin (200 IU/mL, international units (IU)) exhibited similar blood glucose level drop (5⁻7%) compared to insulin of standard concentration (100 IU/mL), however, significant increase of serum insulin (40⁻50%) with respect to the preinfusion values was determined. This was additionally confirmed by a distinctive increase of insulin to C-peptide ratio as compared to preinfusion ratio. Moreover, we noticed that this route of administration mimics a multiple dose regimen, able to get a "steady state" for insulin plasma concentration.

Diabetic complications do not hamper improvement of health-related quality of life over the course of treatment of diabetic foot ulcers - the Eurodiale study.

AIMS: Diabetic complications, and in particular diabetic foot ulcers (DFUs), are associated with low health-related quality of life (HRQoL). We evaluated whether the presence of diabetic complications also influenced the improvement of HRQoL during DFU treatment. METHODS: 1088 patients presenting for DFU treatment at the centers participating in the Eurodiale study were followed prospectively up to one year. HRQoL was measured both at presentation and after healing or at end of follow up, using EQ-5D: a standardized instrument consisting of five domains and a summary index. The influence of diabetic comorbidity on the course of HRQoL was evaluated for each of the EQ-5D outcomes in multi-level linear regression analyses, adjusting for baseline characteristics. RESULTS: HRQoL improved in all EQ-5D outcomes over the course of treatment for those DFUs that healed. The few significant differences in the development of HRQoL between patients with and without comorbidity showed a more beneficial development for patients with comorbidity in DFUs that did not heal or healed slowly. CONCLUSIONS: Comorbidity does not hamper improvement of HRQoL in DFU treatment. On the contrary, HRQoL improved sometimes more in patients with certain comorbidity with hard-to-heal ulcers.

Predictors of lower-extremity amputation in patients with an infected diabetic foot ulcer.

OBJECTIVE: Infection commonly complicates diabetic foot ulcers and is associated with a poor outcome. In a cohort of individuals with an infected diabetic foot ulcer, we aimed to determine independent predictors of lower-extremity amputation and the predictive value for amputation of the International Working Group on the Diabetic Foot (IWGDF) classification system and to develop a risk score for predicting amputation. RESEARCH DESIGN AND METHODS: We prospectively studied 575 patients with an infected diabetic foot ulcer presenting to 1 of 14 diabetic foot clinics in 10 European countries. RESULTS: Among these patients, 159 (28%) underwent an amputation. Independent risk factors for amputation were as follows: periwound edema, foul smell, (non)purulent exudate, deep ulcer, positive probe-to-bone test, pretibial edema, fever, and elevated C-reactive protein. Increasing IWGDF severity of infection also independently predicted amputation. We developed a risk score for any amputation and for amputations excluding the lesser toes (including the variables sex, pain on palpation, periwound edema, ulcer size, ulcer depth, and peripheral arterial disease) that predicted amputation better than the IWGDF system (area under the ROC curves 0.80, 0.78, and 0.67, respectively). CONCLUSIONS: For individuals with an infected diabetic foot ulcer, we identified independent predictors of amputation, validated the prognostic value of the IWGDF classification system, and developed a new risk score for amputation that can be readily used in daily clinical practice. Our risk score may have better prognostic accuracy than the IWGDF system, the only currently available system, but our findings need to be validated in other cohorts.

Health-related quality of life predicts major amputation and death, but not healing, in people with diabetes presenting with foot ulcers: the Eurodiale study.

OBJECTIVE: Low health-related quality of life (HRQoL) has been consistently reported to be associated with poor prognosis for a variety of health outcomes in various settings. We aimed to evaluate whether HRQoL in patients presenting with new diabetic foot ulcers (DFUs) has prognostic significance for ulcer healing, major amputation, and death. RESEARCH DESIGN AND METHODS: We followed 1,088 patients with new DFUs presenting for treatment at one of the 14 centers in 10 European countries participating in the Eurodiale (European Study Group on Diabetes and the Lower Extremity) study, prospectively until healing (76.9%), major amputation (4.6%), or death (6.4%) up to a maximum of 1 year. At baseline, patient and ulcer characteristics were recorded as well as EQ-5D, a standardized instrument consisting of five domains and a visual analog scale for use as a measure of HRQoL. The prognostic influence of the EQ-5D domains was evaluated in multivariable Cox regression analyses on the time-to-event data, adjusting for baseline clinical characteristics of the ulcer and comorbidities. RESULTS: While predictive effects of HRQoL, adjusted for possible confounders, were absent for healing, decreased HRQoL, especially in the physical domains, was statistically significant for major amputation (mobility, self-care, usual activities) and death (self-care, usual activities, pain/discomfort). CONCLUSIONS: Low HRQoL appears to be predictive for major amputation and death, but high HRQoL does not increase healing. Future studies into the influence of HRQoL on ulcer outcome are important in attempts to decrease treatment failure and mortality.

Optimal organization of health care in diabetic foot disease: introduction to the Eurodiale study.

This article describes the rationale and protocol of a large data collection study in patients with new diabetic foot ulcers by the Eurodiale study group, a consortium of centers of expertise in the field of diabetic foot disease within Europe. This study is a multicenter, observational, prospective data collection study. Its main aim is to determine the major factors determining clinical outcome and outcome in terms of health-related quality of life and health care consumption. Between September 1, 2003, and October 1, 2004, in 14 European centers, all consecutive patients with diabetes and a new foot ulcer were included in the study and followed until the end point or for a maximum of 1 year. End points were healing of the foot, major amputation, or death. Data were collected on patient, foot, and ulcer characteristics and on diagnostic and management procedures. Furthermore, data were collected on health care organization, quality of life, and resource use. A total of 1232 patients were included in the study. Sixty-three percent of the patients were referred by their general practitioner or were self-referrals. Twenty-seven percent of the patients were admitted at the time of inclusion; 1088 patients were followed until the end point. "Optimal Organization of Health Care in Diabetic Foot Disease" is one of the first large multicenter studies in the field of diabetic foot disease on clinical presentation, clinical outcome, quality of life, resource utilization, and health care organization and their interrelationships. These data will provide us with new insights that enable us to improve care for these patients and guide the development of new studies in this area. The results of this study are the subject of a separate presentation.