Role of neuropathy and high foot pressures in diabetic foot ulceration

OBJECTIVE: High plantar foot pressures in association with peripheral neuropathy have been ascertained to be important risk factors for ulceration in the diabetic foot. Most studies investigating these parameters have been limited by their size and the homogeneity of study subjects. The objective of this study was therefore to ascertain the risk of ulceration associated with high foot pressures and peripheral neuropathy in a large and diverse diabetic population. RESEARCH DESIGN AND METHODS: We studied a cross-sectional group of 251 diabetic patients of Caucasian (group C) (n=121), black (group B) (n=36), and Hispanic (group H) (n=94) racial origins with an overall age of 58.5+/-12.5 years (range 20-83). There was an equal distribution of men and women across the entire study population. All patients underwent a complete medical history and lower extremity evaluation for neuropathy and foot pressures. Neuropathic parameters were dichotomized (0/1) into two high-risk variables: patients with a vibration perception threshold (VPT) > or =25 V were categorized as HiVPT (n=132) and those with Semmes-Weinstein monofilament tests > or =5.07 were classified as HiSWF (n=190). The mean dynamic foot pressures of three footsteps were measured using the F-scan mat system with patients walking without shoes. Maximum plantar pressures were dichotomized into a high-pressure variable (Pmax6) indicating those subjects with pressures > or =6 kg/cm2 (n=96). A total of 99 patients had a current or prior history of ulceration at baseline. RESULTS: Joint mobility was significantly greater in the Hispanic cohort compared with the other groups at the first metatarsal-phalangeal joint (C 67+/-23 degrees, B 69+/-23 degrees, H 82+/-23 degrees, P=0.000), while the subtalar joint mobility was reduced in the Caucasian group (C 21+/-8 degrees, B 26+/-7 degrees, H 27+/-11 degrees, P=0.000). Maximum plantar foot pressures were significantly higher in the Caucasian group (C 6.7+/-2.9 kg/cm2, B 5.7+/-2.8 kg/cm2, H 4.4+/-1.9 kg/cm2, P=0.000). Univariate logistic regression for Pmax6 on the history of ulceration yielded an odds ratio (OR) of 3.9 (P=0.000). For HiVPT, the OR was 11.7 (P=0.000), and for HiSWF the OR was 9.6 (P=0.000). Controlling for age, diabetes duration, sex, and race (all P < 0.05), multivariate logistic regression yielded the following significant associations with ulceration: Pmax6 (OR=2.1, P=0.002), HiVPT (OR=4.4, P=0.000), and HiSWF (OR=4.1, P=0.000). CONCLUSIONS: We conclude that both high foot pressures (> or =6 kg/cm2) and neuropathy are independently associated with ulceration in a diverse diabetic population, with the latter having the greater magnitude of effect. In black and Hispanic diabetic patients especially, joint mobility and plantar pressures are less predictive of ulceration than in Caucasians.     

The association between callus formation, high pressures and neuropathy in diabetic foot ulceration

The presence of an ulcer beneath callus on the diabetic foot has been a well-documented and common clinical finding. We have conducted a prospective study to examine whether callus can be used to predict plantar intrinsic neuropathic diabetic foot ulcer formation. Sixty-three diabetic patients (43 male, 25 Type 1), median age 62 years (IQ range 52, 67), median diabetes duration 17 years (IQ range 8,25) participated in the study. All had neuropathy and peak plantar foot pressures (measured using a dynamic optical pedobarograph) > or = 10 kg cm-2. Calluses and previous ulcers were documented and classified. All ulcers occurring prior to and during the study were recorded, re-examination was 15.4 (range 10-22) months from baseline. Seven ulcers (6 patients) occurred during the study. Pressures were higher in the ulcer than non-ulcer sub-group (p = 0.04) with a relative risk of developing an ulcer of 4.7 for an area of elevated plantar pressure. This compares with a relative risk of 11.0 for an ulcer developing under an area of callus, and a relative risk of 56.8 for an ulcer developing on a site of previous ulceration. This study confirms that a history of previous ulceration is the highest risk factor for ulceration and demonstrates, for the first time, that the presence of plantar callus is highly predictive of subsequent ulceration. Careful history taking and examination of the foot to detect the presence of callus require no special training or equipment and callus should be recognized as a 'high risk' factor for foot ulceration.     

Ankle weight effect on gait: orthotic implications

Oxygen consumption during ambulation was measured in 10 normal subjects wearing ankle weights of 0.91 kg, 1.82 kg, and 2.73 kg, either on the right ankle or bilaterally. Subjects walked at self-selected speeds and oxygen consumption was measured over 1-minute intervals during steady-state walking. Oxygen consumption per unit distance and oxygen consumption rate demonstrated significant positive linear correlations with added weight (P = .001, P = 0.007, respectively). Velocity demonstrated a significant decrease when correlated with added weight (P = 0.03). Multiple regression analysis was used to relate these measures of oxygen consumption rates to velocity, age, and added weight, yielding predictive relationships. Based on these results, the weight of orthoses should be minimized in order to maximize walking velocity and minimize oxygen consumption per unit distance. The advantage of a light-weight, molded plastic ankle-foot orthosis (AFO) over heavier AFO designs is demonstrated by this study.     

Apolipoproteins in obesity: effect of weight loss

We evaluated serum concentrations of apoprotein (APO) A1, B, total cholesterol, triglycerides, high density cholesterol (HDL-C), and low density cholesterol (LDL-C) in twelve obese subjects whose body mass index (BMI) was > or = 30 before and after a clinically significant weight loss was obtained utilizing a very-low calorie diet (VLCD) consisting of liquid protein (Optifast) providing 800 calories a day. At baseline, the mean weight +/- SD was 119.77 Kg and decreased significantly to 89.29 +/- 13.46 Kg by 24 weeks. Statistically significant reductions of APO-A1, APO-B, total cholesterol, and triglyceride concentrations were also observed along with the weight loss. LDL-C decreased from 156.0 +/- 55.9 mg/dL to 122.5 +/- 42.2 mg/dL (4.03 +/- 1.4 to 3.16 +/- 1.1 mmol/L), but this difference was not statistically significant. There was no significant change in the HDL-C and the ratios of APO-A1 to APO-B. We conclude that the use of VLCD is associated with changes in the lipid pattern that lower the cardiovascular risk profile in addition to the beneficial effects of weight loss itself.     

The effect of maternal obesity on the accuracy of fetal weight estimation

OBJECTIVE: To determine if maternal obesity affects the accuracy of either clinical or sonographic fetal weight estimations. METHODS: In a year-long study, 998 singleton pregnancies of 26-43 weeks' gestation underwent both clinical (Leopold) and sonographic (Shepard and Hadlock) fetal weight estimation within 5 days of delivery (mean 1.1, 95% confidence interval 1.0-1.3). Patients were stratified into four different groups based on increasing maternal body mass index (BMI): underweight (less than 19.8), normal weight (19.8-26.0), overweight (26.1-29.0), and obese (more than 29.0). The various estimations of fetal weight were compared with actual birth weight, and the mean absolute percent error was calculated for each specific method and analyzed among the four BMI groups. RESULTS: For each method of weight estimation, there was no difference (specifically, no increase) in the magnitude of the absolute percent error with increasing maternal obesity. Regardless of maternal size, almost half of the weight predictions were within 5% of the actual birth weight. CONCLUSION: Increasing maternal obesity does not alter or decrease the accuracy of either clinical or sonographic fetal weight estimations. Therefore, fetal weight predictions provide equally accurate and valid guidelines for determining management decisions in women, regardless of body size.     

Collagen metabolism in obesity: the effect of weight loss

OBJECTIVE: To investigate the impact of obesity, fat distribution and weight loss on collagen turnover using serum concentrations of the carboxyterminal propeptide of type I procollagen (S-PICP) and the aminoterminal propeptide of type III pro-collagen (S-PIIINP) as markers for collagen turnover. DESIGN: Blood samples were obtained once at baseline, and after 8 and 16 weeks of dietary treatment (5.0 MJ/day diet). SETTING: Outpatient clinic of Hvidovre University Hospital. MAIN OUTCOME MEASURES: S-PICP, S-PIIINP, fat distribution and weight loss. RESULTS: S-PIIINP was associated with body weight (r = 0.37; P = 0.004), height (r = 0.27; P = 0.04), waist circumference (r = 0.35; P = 0.007), as well as with WHR (r = 0.33; P = 0.01) and was inversely correlated to age (r = -0.40; P = 0.002). Compared with randomly selected controls from a large pool of healthy volunteers, the obese patients had elevated S-PIIINP values before as well as during weight loss, whereas S-PICP levels were within the normal range and did not correlate with any anthropometric measures. The average weight loss after 16 weeks dietary treatment was 8.1 kg (s.d. = 0.8). S-PIIINP decreased during the 16 weeks of energy restriction (P < 0.05) and changes in S-PIIINP was correlated to body weight loss (r = 0.32; P < 0.05) and to changes in waist circumference (r = 0.34; P < 0.05) as well as changes in WHR (r = 0.30; P < 0.05). CONCLUSION: S-PIIINP is elevated in obesity and associated with body fat distribution, suggesting an increased turnover of type III collagen related to obesity in general and to abdominal obesity in particular. S-PIIINP levels decreases during weight loss in obese subjects, whereas S-PICP levels seems un-related to obesity and weight loss.     

The pathophysiology and treatment of diabetic foot disease

Two rare cases of mesenteric fibromatosis are presented. The first patient had a right upper quadrant mass and colicky abdominal pain. The tumor originated from the mesentery of the colon and it infiltrated the gallbladder, cystic duct, and the liver. The second patient had severe hematemesis and melena. The origin of the tumor, which infiltrated 3/4 part of the stomach, the gastrohepatic ligament, the first part of the duodenum, and the liver could not be determined. In the first patient, partial colectomy and cholecystectomy were performed and the liver lesion was completely excised. The second patient underwent subtotal gastrectomy and left lobectomy of the liver. The first part of the duodenum was excised. Gastrojejunostomy was performed. No recurrence was recorded in either patients during 16 and 13 months follow-up, respectively. In this report, diagnostic aids, differential diagnosis and treatment of this rare disease are discussed.     

Effects of television on metabolic rate: potential implications for childhood obesity

The effects of television viewing on resting energy expenditure (metabolic rate) in obese and normal-weight children were studied in a laboratory setting. Subjects were 15 obese children and 16 normal-weight children whose ages ranged from 8 to 12 years. All subjects had two measured of resting energy expenditure obtained while at rest and one measurement of energy expenditure taken while viewing television. Results indicated that metabolic rate during television viewing was significantly lower (mean decrease of 211 kcal extrapolated to a day) than during rest. Obese children tended to have a larger decrease, although this difference was not statistically significant (262 kcal/d vs 167 kcal/d, respectively). It was concluded that television viewing has a fairly profound lowering effect of metabolic rate and may be a mechanism for the relationship between obesity and amount of television viewing.     

The effect of wrist and arm postures on peak pinch strength

This paper examines the effect of various arm postures on peak pinch strength. Twenty (20) able-bodied, male subjects volunteered to participate in a set of two experiments. The first experiment examined the effect of shoulder and elbow posture on peak pinch strength. The second experiment examined the effect of forearm posture, wrist posture, and pinch type on peak pinch strength. Results from the first experiment indicated that elbow posture had a significant effect on pinch strength. It was documented that extreme elbow flexion decreased pinch strength by up to 9%. Results from the second experiment indicated that deviated wrist postures, forearm postures, and pinch type significantly decreased pinch strength as much as 33%. Ergonomic guidelines which utilize the above factors as significant modifiers of pinch strength capacity may assist ergonomists to reduce the risk of injury and development of cumulative trauma disorders in the workplace.     

Lectin activities of cytokines and growth factors: function and implications for pathology

The discovery that certain cytokines have carbohydrate-binding (lectin) properties opens new concepts in the understanding of their mechanism of action. The carbohydrate-recognition domain, which is localized opposite to the receptor-binding domain, makes these molecules bi-functional. The expression of the biological activity of the cytokine relies on its carbohydrate-binding activity which allows the association of the cytokine receptor with molecular complexes comprising the specific kinase involved in receptor phosphorylation and in specific signal transduction. It is expected that blood accumulation of free or membrane-bound glucan ligands of cytokines may dramatically perturb their endogenous function inducing specific immunodeficiencies.     

Resection of the metatarsal head for diabetic foot ulcers

Dobutamine-induced hypotension has been disregarded as a marker of more severe functional abnormalities in patients with suspected coronary artery disease. However, its functional significance in patients with myocardial infarction has not been studied. The aim of this study was to define the predictors of systolic blood pressure (SBP) response to dobutamine in patients with previous myocardial infarction. Dobutamine stress (up to 40 microg/kg per minute) echocardiography was performed in 326 patients with prior myocardial infarction referred for evaluation of myocardial ischemia. A 16-segment, four-grade score model was used to assess left ventricular function. Wall motion score index was derived by summation of wall motion score divided by 16. SBP and heart rate increased from rest to peak dobutamine stress (127 +/- 22 vs 134 +/- 27 mm Hg and 72 +/- 14 vs 122 +/- 24 bpm, p < 0.00001 in both). An increase of SBP > or = 30 mm Hg occurred in 50 patients (15%). By multivariate analysis, independent predictors of failure of SBP increase were higher peak wall motion score index (p < 0.001), higher resting SBP (p < 0.01), and medication with calcium channel blockers (p < 0.05). SBP drop > or = 20 mm Hg occurred in 54 patients (17%). Independent predictors of SBP drop were higher resting wall motion score index (p < 0.001), higher resting SBP (p < 0.0001), and older age (p < 0.05). In patients with myocardial infarction, left ventricular function and baseline systolic blood pressure are powerful predictors of SBP response to dobutamine stress testing.     

Risk factors for diabetic foot ulceration: a logical approach to treatment

Children with limb deficiencies or amputations of the lower extremities should be enabled to stand or walk according to their state of development, because standing and walking are among the most important preconditions for the best possible integration. Supplying them with a prosthesis, orthosis and orthoprosthesis is therefore indispensable for rehabilitation. While a prosthesis replaces parts of the extremities, an orthosis stabilizes the existing extremity. Orthoprostheses compensate longitudinal malformations, have a supporting effect, allow growth to be controlled and compensate for shortening. Just as important as the remedy is early medical treatment. The medical team taking care of the patient works out a treatment plan where responsible cooperation with the parents is of utmost importance. The focus of all efforts is, of course, the handicapped child. Examples are used to demonstrate the course of successful rehabilitation of children and adolescents with damaged limbs. Equally the psychological situation of the parents and child is taken into consideration.     

The effect of foot structure on the three-dimensional kinematic coupling behavior of the leg and rear foot

BACKGROUND AND PURPOSE: Differences in foot structures have been reported to account for the large variability in findings in previous studies that have examined the relationship between foot structure and the interdependent rotations of the lower extremity. The purpose of this study was to determine, in individuals with radiographically distinct foot structures, the effect of foot structure on three-dimensional kinematic behavior of the leg and rear foot during running. SUBJECTS AND METHODS: Based on radiographic measurements, 10 recreational runners were assigned to a low rear-foot group and another 10 recreational runners were assigned to a high rear-foot group. Three-dimensional kinematic data were collected during treadmill running. Individual axis rotations and the "coupled" relationship between the leg and rear-foot segments were defined using a Cardan angle system of three ordered rotations. RESULTS: The predominant rotations suggest a combined subtalar and talocalcaneal joint axis to favor calcaneal eversion and inversion for the low rear-foot group and tibial medial and lateral rotation for the high rear-foot group. Group differences were also found for the coupling ratio, which described the proportion of calcaneal eversion and inversion transferred or coupled to tibial axial rotation. CONCLUSION AND DISCUSSION: The rotational patterns and coupling response unique to each foot group may enhance our understanding of lower-extremity injuries related to certain foot structures. An assessment of the coupling relationship in combination with traditional frontal-plane measurements may better guide decisions regarding selection of footwear and orthoses.     

Combined behavioral and pharmacologic treatment for obesity: Predictors of successful weight maintenance.

Fenfluramine treatment in combination with behavior therapy has produced better weight loss but greater recidivism than behavioral treatment alone. The present study tested a different anorectic agent, diethylpropion hydrochloride (Tenuate), with a 20-week cognitive-behavioral (CB) therapy program. A placebo plus CB therapy and a CB therapy alone condition were also included. All treatment conditions showed significant weight loss, with the Tenuate/CB group doing better than the other groups only during the latter half of the drug treatment period. At 6-month follow-up, Tenuate/CB subjects showed significant regain, whereas the other groups did not. By 1 year, however, none of the groups showed further significant weight gain. Predictors of greater weight loss included (a) greater initial weight loss, (b) agreement with the philosophy that a specified low calorie diet would not have helped the program, and (c) stronger feelings (among Tenuate/CB subjects in particular) of self-efficacy regarding weight control. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of physiologic and mechanical aging on the performance of peak flowmeters

PURPOSE: To investigate the effects of physiologic and mechanical aging on peak flowmeters. MATERIALS AND METHODS: Eight each of MiniWright (MW; Clement Clark; Harlow, UK), Personal-Best (PB; HealthScan Products; Cedar Grove, NJ), Vitalograph (V; Vitalograph Ltd; Buckingham, UK), and Breath-Taker (BT; Medical Development Australia; Melbourne, Australia) peak flowmeters were assessed for accuracy and repeatability before and after aging using a computer-driven syringe to deliver peak flows from 100 to 700 L/min. Four of each type of flowmeter were physiologically aged by normal subjects performing up to six peak flows daily for 1 year. The remaining four of each flowmeter were mechanically aged using an accelerated aging device to deliver 2,000 exponential waveforms with a peak flow of 600 L/min over a period of 3 h. RESULTS: The V and BT flowmeters were linear and accurate over the range 100 to 700 L/min, while the PB overread at high flows. The MW was alinear throughout. The SD of the difference between readings before and after aging ranged from 8.6 to 40.6 L/min (mean, 9.2). Comparing the slopes of the relationship of actual against reference peak expiratory flow (PEF) showed that 16 flowmeters--5 BTs, 6 MWs, 4 PBs, and 1 V had no significant change in slope after aging. Mechanical aging caused a consistent underreading in PEF at high flow rates. Physiologic aging showed a more variable pattern both within and between flowmeter types. The MW was the most affected by physiologic aging, producing overestimates of PEF by as much as 100 L/min at 500 L/min. CONCLUSIONS: We conclude that the effects of physiologic and mechanical aging are different, and that while mechanical aging may provide a guide to the effects of aging, studies using physiologic aging would be more appropriate.     

Energy density, palatability, and satiety: implications for weight control

High energy density tends to be associated with high palatability, and vice versa. As a rule, energy-dense foods are palatable but not satiating, whereas foods with low energy density are more satiating but less palatable. Low-energy-density foods are typically those that contain the most water and the least fat. Reducing energy density while maintaining palatability is a continuing challenge to the food industry.