bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assessing Postural Control and Postural Control Strategy in Diabetes Patients Using Innovative and Wearable Technology
Authors: Najafi Bijan , Horn Deena , Marclay Samuel , Crews Ryan T. , Wu Stephanie , Wrobel James S. 
Published: January 2014

Introduction: Currently, diagnosis of patients with postural instability relies on a rudimentary clinical examination. This article suggests an innovative, portable, and cost-effective prototype to evaluate balance control objectively. Methods: The proposed system uses low-cost, microelectromechanical sensor, body-worn sensors (BalanSens™) to measure the motion of ankle and hip joints in three dimensions. We also integrated resulting data into a two-link biomechanical model of the human body for estimating the two-dimensional sway of the center of mass (COM) in anterior-posterior (AP) and medial-lateral (ML) directions. A new reciprocal compensatory index (RCI) was defined to quantify postural compensatory strategy (PCS) performance. To validate the accuracy of our algorithms in assessing balance, we investigated the two-dimensional sway of COM and RCI in 21 healthy subjects and 17 patients with diabetic peripheral neuropathic (DPN) complications using the system just explained. Two different conditions were examined: eyes open (EO) and eyes closed (EC) for duration of at least 30 seconds. Results were compared with center of pressure sway (COP) as measured by a pressure platform (Emed-x system, Novel Inc., Germany). To further investigate the contribution of the somatosensory (SOM) feedback to balance control, healthy subjects performed EO and EC trials while standing on both a rigid and a foam surface. Results: A relatively high correlation was observed between COM measured using BalanSens and COP measured using the pressure platform ( r = 0.92). Results demonstrated that DPN patients exhibit significantly greater COM sway than healthy subjects for both EO and EC conditions ( p < 0.005). The difference becomes highly pronounced while eyes are closed (197 ± 44 cm2 vs 68 ± 56 cm2). Furthermore, results showed that PCS assessed using RCI is significantly better in healthy subjects compared to DPN subjects for both EO and EC conditions, as well as in both ML and AP directions ( p < 0.05). Alteration in SOM feedback in healthy subjects resulted in diminished RCI values that were similar to those seen in DPN subjects ( p > 0.05). Discussion/Conclusion: This study suggested an innovative system that enables the investigation of COM as well as postural control compensatory strategy in humans. Results suggest that neuropathy significantly impacts PCS.
Association between Foot Temperature and Sudomotor Dysfunction in Type 2 Diabetes
Authors: Papanas Nikolaos , Papatheodorou Konstantinos , Papazoglou Dimitrios , Kotsiou Stamatia , Maltezos Efstratios 
Published: January 2014

Background and Aims: Increased foot skin temperature has been described as a feature of diabetic neuropathy. The aim of this present study was to investigate the association between foot temperature and sudomotor dysfunction in type 2 diabetes mellitus. Patients and Methods: This study included 51 patients (group A: 25 men, mean age 61.14 ± 6.11 years) without sudomotor dysfunction and 52 patients (group B: 25 men, mean age 59.54 ± 6.18 years) with sudomotor dysfunction. Sudomotor dysfunction was defined as time until complete Neuropad™ color change from blue to pink exceeding 600 s in at least one foot. Time until complete color change of the test was also recorded. Foot skin temperature was measured with a handheld infrared thermometer on the plantar aspect of the foot at the level of the first metatarsal head. Results: On both feet, temperature was significantly higher in group B than in group A (right foot, group A versus group B, 30.62 ± 1.13 °C versus 32.12 ± 1.06 °C, p < .001; left foot, group A versus group B, 30.65 ± 1.06 °C versus 32.19 ± 1.10 °C, p < .001). There was a significant positive correlation between time to complete Neuropad color change and foot skin temperature (right foot, r = 0.742, p < .001; left foot, r = 0.758, p < .001), which was confirmed in both groups. Conclusions: Patients with sudomotor dysfunction have significantly higher foot temperature than those without sudomotor dysfunction. Foot temperature is positively correlated with severity of sudomotor dysfunction, as evaluated by the time to complete Neuropad color change.
Diabetic Foot Biomechanics and Gait Dysfunction
Authors: Wrobel James S. , Najafi Bijan 
Published: January 2014

Background: Diabetic foot complications represent significant morbidity and precede most of the lower extremity amputations performed. Peripheral neuropathy is a frequent complication of diabetes shown to affect gait. Glycosylation of soft tissues can also affect gait. The purpose of this review article is to highlight the changes in gait for persons with diabetes and highlight the effects of glycosylation on soft tissues at the foot-ground interface. Methods: PubMed, the Cochrane Library, and EBSCOhost® on-line databases were searched for articles pertaining to diabetes and gait. Bibliographies from relevant manuscripts were also searched. Findings: Patients with diabetes frequently exhibit a conservative gait strategy where there is slower walking speed, wider base of gait, and prolonged double support time. Glycosylation affects are observed in the lower extremities. Initially, skin thickness decreases and skin hardness increases; tendons thicken; muscles atrophy and exhibit activation delays; bones become less dense; joints have limited mobility; and fat pads are less thick, demonstrate fibrotic atrophy, migrate distally, and may be stiffer. Interpretation: In conclusion, there do appear to be gait changes in patients with diabetes. These changes, coupled with local soft tissue changes from advanced glycosylated end products, also alter a patient's gait, putting them at risk of foot ulceration. Better elucidation of these changes throughout the entire spectrum of diabetes disease can help design better treatments and potentially reduce the unnecessarily high prevalence of foot ulcers and amputation.
Outpatient-to-Inpatient Transition of Insulin Pump Therapy: Successes and Continuing Challenges
Authors: Nassar Adrienne A. , Partlow Brenda J. , Boyle Mary E. , Castro Janna C. , Bourgeois Peggy B. , Cook Curtiss B. 
Published: January 2014

Background: Insulin pump therapy is a complex technology prone to errors when employed in the hospital setting. When patients on insulin pump therapy require hospitalization, practitioners caring for them must decide whether to allow continued pump use. We provide the largest review regarding transitioning insulin pump therapy from the outpatient to inpatient setting. Method: Records of inpatient insulin pump users were retrospectively analyzed at a metropolitan Phoenix hospital between January 2006 and December 2009. Adherence to institutional procedures on insulin pump use was assessed, glycemic control was determined, and adverse events were examined. Results: We examined records on 65 patients with insulin pumps, totaling 125 hospitalizations. Mean (standard deviation) patient age was 55 (17) years, diabetes duration was 27 (14) years, pump duration was 6 (5) years, length of hospital stay was 4.7 (6.3) days, hemoglobin A1c was 7.3 (1.3)%, 85% had type 1 diabetes mellitus, 57% were women, and 97% were white. Admissions involving insulin pumps increased (23 in 2006, 17 in 2007, 40 in 2008, and 45 in 2009). Insulin pump therapy was continued in 83 (66%) hospitalizations. Among these hospitalizations, endocrinology consultations were obtained in 89%, consent agreements were found in 83%, insulin pump order sets were completed in 89%, admission glucose was checked in 100%, and nursing assessments of pump insertion sites were documented in 89%, but bedside insulin pump flow sheets were found in only 55%. Mean glucose of 175 (57) mg/dl was not significantly different than that in hospitalizations where insulin pumps were discontinued [175 (42) mg/dl] or used intermittently [177 (7) mg/dl]. There was one instance of a pump catheter kinking; however, no other adverse events (pump site infections, mechanical pump failure, diabetic ketoacidosis) were observed, and there were no use-related fatalities. Conclusions: Most patients using insulin pumps can safely have their therapy transitioned when hospitalized. A policy on inpatient continuous subcutaneous insulin infusion use can be successfully implemented. Compliance with required procedures can be achieved, although there was room to improve adherence with some process measures. Further study is needed to determine how to optimize glycemic control when pumps are allowed during hospitalization.
Nonlinear Metabolic Effect of Insulin Across the Blood Glucose Range in Patients with Type 1 Diabetes Mellitus
Authors: Chan Alice , Heinemann Lutz , Anderson Stacey M. , Breton Marc D. , Kovatchev Boris P. 
Published: January 2014

Background: For insulin therapy to successfully maintain blood glucose (BG) levels of patients with type 1 diabetes mellitus (T1DM) in normoglycemia, it is necessary to understand if the metabolic effect of insulin across the BG range is linear or not. Methods: We assess the ability of insulin to lower BG in patients with T1DM in hypoglycemia and hyperglycemia. The net metabolic effect of insulin, defined as the total effect resulting from both reduced endogenous glucose production and increased glucose uptake, was used to define the insulin effectiveness (IE), a measure that indicates the amplitude of glucose lowering that a unit of active insulin can achieve at a given BG level. The IE was assessed in hypoglycemia and hyperglycemia through two separate studies. In the first study, patients were subjected to a hyperinsulinemic euglycemic and hypoglycemic glucose clamp. In the second study, another group of patients were clamped at a hyperglycemic level. Results: The IE increased by 75% when BG dropped from 90 to 50 mg/dl at a steady rate of 1 mg/d1/min and decreased by 10% when BG was increased from 100 to 200 mg/d1. Conclusions: The net metabolic effect of insulin is nonlinear across the BG range and is amplified in hypoglycemia and dampened in hyperglycemia. Most importantly, the BG lowering per unit of insulin is accelerated when falling into hypoglycemia. The understanding of the accelerated risk for hypoglycemia with falling glucose levels will help the design of more robust hypoglycemia prevention and detection systems.
Bolus Guide: A Novel Insulin Bolus Dosing Decision Support Tool Based on Selection of Carbohydrate Ranges
Authors: Shapira Gali , Yodfat Ofer , HaCohen Arava , Feigin Paul , Rubin Richard 
Published: January 2014

Background: Optimal continuous subcutaneous insulin infusion (CSII) therapy emphasizes the relationship between insulin dose and carbohydrate consumption. One widely used tool (bolus calculator) requires the user to enter discrete carbohydrate values; however, many patients might not estimate carbohydrates accurately. This study assessed carbohydrate estimation accuracy in type 1 diabetes CSII users and compared simulated blood glucose (BG) outcomes using the bolus calculator and the “bolus guide,” an alternative system based on ranges of carbohydrate load. Methods: Patients ( n = 60) estimated the carbohydrate load of a representative sample of meals of known carbohydrate value. The estimated error distribution [coefficient of variation (CV)] was the basis for a computer simulation ( n = 1.6 million observations) of insulin recommendations for the bolus guide and bolus calculator, translated into outcome blood glucose (OBG) ranges (=60, 61–200, >201 mg/dl). Patients ( n = 30) completed questionnaires assessing satisfaction with the bolus guide. Results: The CV of typical meals ranged from 27.9% to 44.5%. The percentage of simulated OBG for the calculator and the bolus guide in the <60 mg/dl range were 20.8% and 17.2%, respectively, and 13.8% and 15.8%, respectively, in the >200 mg/dl range. The mean and median scores of all bolus guide satisfaction items and ease of learning and use were 4.17 and 4.2, respectively (of 5.0). Conclusion: The bolus guide recommendation based on carbohydrate range selection is substantially similar to the calculator based on carbohydrate point estimation and appears to be highly accepted by type 1 diabetes insulin pump users.
A Single-Center, Open, Comparative Study of the Effect of Using Self-Monitoring of Blood Glucose to Guide Therapy on Preclinical Atherosclerotic Markers in Type 2 Diabetic Subjects
Authors: Mohan Viswanathan , Ravikumar Radhakrishnan , Poongothai Subramani , Amutha Anandakumar , Sowmya Santhamma , Karkhuzali Kulasegaran , Parkin Christopher G. 
Published: January 2014

Background: The aim of our study was to determine the effect of treatment based on preprandial and postprandial self-monitoring of blood glucose (SMBG) on the progression of carotid intima-medial thickness (CIMT) in noninsulin-treated type 2 diabetes mellitus (T2DM) subjects. Methods: In this 18-month prospective trial, we recruited subjects 18–70 years of age, treated with metformin and sulfonylurea, with a standardized hemoglobin A1c (HbA1c) level ⩽9.0%. Subjects were randomized to use of fasting/preprandial (FP) SMBG results to adjust evening medication or use of postprandial (PP) SMBG results to adjust morning medication. The primary end point was change in CIMT; change in HbA1c was a secondary end point. Results: Of the 300 subjects randomized, 280 (140 in each group) completed all biochemical tests and CIMT analysis. Carotid intima-medial thickness was reduced significantly in PP subjects from 0.78 (±0.15) mm to 0.73 (±0.14) mm ( p < 0.005), but no significant CIMT reduction was seen in FP subjects. A significant reduction in HbA1c was also seen in the PP group ( p < 0.005) but not in the FP group 1 ( p = 0.165). significant improvements in body mass index ( p = 0.038), waist circumference ( p < 0.001), systolic blood pressure ( p = 0.008), and serum cholesterol ( p = 0.02) were also seen in PP subjects but not in FP subjects. Conclusion: Use of postprandial SMBG data to adjust therapy was associated with a significant regression of carotid intima-medial thickening and a reduction in HbA1c in T2DM, whereas no significant improvement in these parameters was seen in subjects who used fasting/preprandial SMBG data for therapy adjustment.
Evolution of Data Management Tools for Managing Self-Monitoring of Blood Glucose Results: A Survey of iPhone Applications
Authors: Rao Anoop , Hou Philip , Golnik Timothy , Flaherty Joseph , Vu Sonny 
Published: January 2014

Background: Studies have indicated that sharing of self-monitoring of blood glucose (SMBG) data and subsequent feedback from the health care provider (HCP) can help achieve glycemic goals such as a reduction in glycated hemoglobin. Electronic SMBG data management and sharing tools for the PC and smartphones may help in reducing the effort to manage SMBG data. Methods: We reviewed software and top-ranking applications (Apps) for the iPhone platform to document the variety of useful features. Additionally, in an attempt to assess metrics such as task analysis and user friendliness of diabetes Apps, we observed and surveyed patients with diabetes as they recorded and relayed sample SMBG results to their hypothetical HCP using three Apps. Results: Observation and survey demonstrated that the WaveSense Diabetes Manager allowed the participants to complete preselected SMBG data entry and relay tasks faster than other Apps. The survey revealed patient behavior patterns that would be useful in future App development. Conclusion: Being able to record, analyze, seamlessly share, and obtain feedback on the SMBG data using an iPhone/iTouch App might potentially benefit patients. Trends in SMBG data management and the possibility of having interoperability of blood glucose monitors and smartphones may open up new avenues of diabetes management for the technologically savvy patient.
Zone Model Predictive Control: A Strategy to Minimize Hyper- and Hypoglycemic Events
Authors: Grosman Benyamin , Dassau Eyal , Zisser Howard C. , Jovanovič Lois , Doyle Francis J. 
Published: January 2014

Background: Development of an artificial pancreas based on an automatic closed-loop algorithm that uses a subcutaneous insulin pump and continuous glucose sensor is a goal for biomedical engineering research. However, closing the loop for the artificial pancreas still presents many challenges, including model identification and design of a control algorithm that will keep the type 1 diabetes mellitus subject in normoglycemia for the longest duration and under maximal safety considerations. Method: An artificial pancreatic β-cell based on zone model predictive control (zone-MPC) that is tuned automatically has been evaluated on the University of Virginia/University of Padova Food and Drug Administration-accepted metabolic simulator. Zone-MPC is applied when a fixed set point is not defined and the control variable objective can be expressed as a zone. Because euglycemia is usually defined as a range, zone-MPC is a natural control strategy for the artificial pancreatic β-cell. Clinical data usually include discrete information about insulin delivery and meals, which can be used to generate personalized models. It is argued that mapping clinical insulin administration and meal history through two different second-order transfer functions improves the identification accuracy of these models. Moreover, using mapped insulin as an additional state in zone-MPC enriches information about past control moves, thereby reducing the probability of overdosing. In this study, zone-MPC is tested in three different modes using unannounced and announced meals at their nominal value and with 40% uncertainty. Ten adult in silico subjects were evaluated following a scenario of mixed meals with 75, 75, and 50 grams of carbohydrates (CHOs) consumed at 7 am, 1 pm, and 8 pm, respectively. Zone-MPC results are compared to those of the “optimal” open-loop preadjusted treatment. Results: Zone-MPC succeeds in maintaining glycemic responses closer to euglycemia compared to the “optimal” open-loop treatment in te three different modes with and without meal announcement. In the face of meal uncertainty, announced zone-MPC presented only marginally improved results over unannounced zone-MPC. When considering user error in CHO estimation and the need to interact with the system, unannounced zone-MPC is an appealing alternative. Conclusions: Zone-MPC reduces the variability of control moves over fixed set point control without the need to detune the controller. This strategy gives zone-MPC the ability to act quickly when needed and reduce unnecessary control moves in the euglycemic range.
Pilot Study for Assessment of Optimal Frequency for Changing Catheters in Insulin Pump Therapy—Trouble Starts on Day 3
Authors: Schmid Volkmar , Hohberg Cloth , Borchert Marcus , Forst Thomas , Pfützner Andreas 
Published: January 2014

Background: Continuous subcutaneous insulin infusion (CSII) by means of insulin pump devices is considered to be one of the most optimal therapies to achieve treatment targets in patients with diabetes mellitus. In CSII, the insulin is delivered through Teflon catheters or steel needle infusion sets, which need to be renewed on a regular basis. This pilot study was performed to investigate the optimal change frequency in daily practice and to explore potential problems that may occur when the sets are used for a more prolonged time than the recommended up to 72 hours of usage (Teflon catheters). Method: Twelve patients with type 1 diabetes participated in the trial [age (mean ± STD): 40.3 ± 12.6 years, body mass index: 26.2 ± 3.3 kg/m2, hemoglobin A1c: 6.7 ± 0.6%]. They were asked to wear their infusion set (Comfort™ or Silhouette®) for increasing periods of 1, 2, 3, 4, and 5 days. After each use, patients completed standardized questionnaires regarding technical and medical issues associated with infusion set use. A health care professional investigated the infusion sites and infusion sets and completed an “infusion set inspection” questionnaire. Blood glucose was measured and recorded to assess a potential Influence of duration of catheter use on glycemic control. Results: Infusion set and injection site problems (itching, bruising, swelling, and pain) started to occur in measurable amounts on the 3rd day of catheter use, and about 40% of patients reported significant issues when using a catheter for 5 days. In parallel, there was a consistent increase in mean daily blood glucose levels that correlated with the number of days of catheter use (e.g., day 1: 7. 5 ± 3.8 mmol/liter, day 3: 8.4 ± 4.2 mmol/liter, day 5: 9.0 ± 4.0 mmol/liter, day 7: 11.6 ± 2.2 mmol/liter, p < 0.05 vs day 1). Conclusions: Using the catheters for 2 days resulted in a safe and well-tolerated therapy. Clinically relevant adverse events started to occur during the 3rd day and their incidence increased constantly with longer use. This was associated with undesired changes in mean glycemic control. Data support the recommendation by the drug and device manufacturers that insulin pump catheters should only be used for 48–72 hours to avoid adverse events and potential metabolic deterioration.
Analyte Flux at a Biomaterial-Tissue Interface over Time: Implications for Sensors for Type 1 and 2 Diabetes Mellitus
Authors: Ekberg Neda Rajamand , Brismar Kerstin , Malmstedt Jonas , Hedblad Mari-Anne , Adamson Ulf , Ungerstedt Urban , Wisniewski Natalie 
Published: January 2014

Objective: The very presence of an implanted sensor (a foreign body) causes changes in the adjacent tissue that may alter the analytes being sensed. The objective of this study was to investigate changes in glucose availability and local tissue metabolism at the sensor-tissue interface in patients with type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM). Method: Microdialysis was used to model implanted sensors. Capillary glucose and subcutaneous (sc) microdialysate analytes were monitored in five T1DM and five T2DM patients. Analytes included glucose, glycolysis metabolites (lactate, pyruvate), a lipolysis metabolite (glycerol), and a protein degradation byproduct (urea). On eight consecutive days, four measurements were taken during a period of steady state blood glucose. Results: Microdialysate glucose and microdialysate-to-blood-glucose ratio increased over the first several days in all patients. Although glucose recovery eventually stabilized, the lactate levels continued to rise. These trends were explained by local inflammatory and microvascular changes observed in histological analysis of biopsy samples. Urea concentrations mirrored glucose trends. Urea is neither produced nor consumed in sc tissue, and so the initially increasing urea trend is explained by increased local capillary presence during the inflammatory process. Pyruvate in T2DM microdialysate was significantly higher than in T1DM, an observation that is possibly explained by mitochondrial dysfunction in T2DM. Glycerol in T2DM microdialysate (but not in T1DM) was higher than in healthy volunteers, which is likely explained by sc insulin resistance (insulin is a potent antilipolytic hormone). Urea was also higher in microdialysate of patients with diabetes mellitus compared to healthy volunteers. Urea is a byproduct of protein degradation, which is known to be inhibited by insulin. Therefore, insulin deficiency or resistance may explain the higher urea levels. To our knowledge, this is the first histological evaluation of a human tissue biopsy containing an implanted glucose monitoring device. Conclusions: Monitoring metabolic changes at a material-tissue interface combined with biopsy histology helped to formulate an understanding of physiological changes adjacent to implanted glucose sensors. Microdialysate glucose trends were similar over 1-week in T1DM and T2DM; however, differences in other analytes indicated wound healing and metabolic activities in the two patient groups differ. We propose explanations for the specific observed differences based on differential insulin insufficiency/resistance and mitochondrial dysfunction in T1DM versus T2DM.