Human Achilles tendon glycation and function in diabetes

Diabetic patients have an increased risk of foot ulcers, and glycation of collagen may increase tissue stiffness. We hypothesized that the level of glycemic control (glycation) may affect Achilles tendon stiffness, which can influence gait pattern. We therefore investigated the relationship between collagen glycation, Achilles tendon stiffness parameters, and plantar pressure in poorly ( n = 22) and well ( n = 22) controlled diabetic patients, including healthy age-matched (45–70 yr) controls ( n = 11). There were no differences in any of the outcome parameters (collagen cross-linking or tendon stiffness) between patients with well-controlled and poorly controlled diabetes. The overall effect of diabetes was explored by collapsing the diabetes groups (DB) compared with the controls. Skin collagen cross-linking lysylpyridinoline, hydroxylysylpyridinoline (136%, 80%, P < 0.01) and pentosidine concentrations (55%, P < 0.05) were markedly greater in DB. Furthermore, Achilles tendon material stiffness was higher in DB (54%, P < 0.01). Notably, DB also demonstrated higher forefoot/rearfoot peak-plantar-pressure ratio (33%, P < 0.01). Overall, Achilles tendon material stiffness and skin connective tissue cross-linking were greater in diabetic patients compared with controls. The higher foot pressure indicates that material stiffness of tendon and other tissue (e.g., skin and joint capsule) may influence foot gait. The difference in foot pressure distribution may contribute to the development of foot ulcers in diabetic patients.

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Cross-Linking in Collagen by Nonenzymatic Glycation Increases the Matrix Stiffness in Rabbit Achilles Tendon

Experimental Diabesity Research ◽

10.1080/15438600490277860 ◽

2004 ◽

Vol 5 (2) ◽

pp. 143-153 ◽

Cited By ~ 145

Author(s):

G. Kesava Reddy

Keyword(s):

Achilles Tendon ◽

Modulus Of Elasticity ◽

Maximum Load ◽

Cross Linking ◽

Matrix Stiffness ◽

Nonenzymatic Glycation ◽

Insoluble Collagen ◽

The Matrix ◽

Phosphate Buffered Saline ◽

Collagen Cross Linking

Nonenzymatic glycation of connective tissue matrix proteins is a major contributor to the pathology of diabetes and aging. Previously the author and colleagues have shown that nonenzymatic glycation significantly enhances the matrix stability in the Achilles tendon (Reddy et al., 2002,Arch. Biochem. Biophys., 399, 174–180). The present study was designed to gain further insight into glycation-induced collagen cross-linking and its relationship to matrix stiffness in the rabbit Achilles tendon. The glycation process was initiated by incubating the Achilles tendons (n = 6) in phosphate-buffered saline containing ribose, whereas control tendons (n = 6) were incubated in phosphate-buffered saline without ribose. Eight weeks following glycation, the biomechanical attributes as well as the degree of collagen cross-linking were determined to examine the potential associations between matrix stiffness and molecular properties of collagen. Compared to nonglycated tendons, the glycated tendons showed increased maximum load, stress, strain, Young's modulus of elasticity, and toughness indicating that glycation increases the matrix stiffness in the tendons. Glycation of tendons resulted in a considerable decrease in soluble collagen content and a significant increase in insoluble collagen and pentosidine. Analysis of potential associations between the matrix stiffness and degree of collagen cross-linking showed that both insoluble collagen and pentosidine exhibited a significant positive correlation with the maximum load, stress, and strain, Young's modulus of elasticity, and toughness (rvalues ranging from .61 to .94) in the Achilles tendons. However, the soluble collagen content present in neutral salt buffer, acetate buffer, and acetate buffer containing pepsin showed an inverse relation with the various biomechanical attributes tested (rvalues ranging from .22 to .84) in the Achilles tendons. The results of the study demonstrate that glycation-induced collagen cross-linking is directly associated with the increased matrix stiffness and other mechanical attributes of the tendon.

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Influence of acetaminophen consumption and exercise on Achilles tendon structural properties in male Wistar rats

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00659.2011 ◽

2012 ◽

Vol 302 (8) ◽

pp. R990-R995 ◽

Cited By ~ 14

Author(s):

Chad C. Carroll ◽

Jamie A. Whitt ◽

Amity Peterson ◽

Brian S. Gump ◽

Jamie Tedeschi ◽

...

Keyword(s):

Achilles Tendon ◽

Water Content ◽

High Performance ◽

Wistar Rats ◽

Collagen Content ◽

Cross Linking ◽

Tissue Water ◽

Tendon Stiffness ◽

Main Effect ◽

Male Wistar Rats

Chronic consumption of acetaminophen (APAP) during exercise training leads to a reduction in tendon stiffness and modulus compared with a placebo. We explored whether this effect could be due to a reduction in tendon collagen content or cross-linking. Ten-week-old male Wistar rats ( n = 50) were divided into placebo or APAP groups and into sedentary or treadmill-exercised groups. APAP (200 mg/kg) or saline was administered once daily by oral gavage. Rats in the exercise groups ran on a treadmill 5 days per week for 8 wk with progression to 60 min per day, 20 m/min, and 8° incline. After 8 wk, lyophilized Achilles tendon samples were assayed for the collagen-specific amino acid hydroxyproline and cross-linking [hydroxylyslpyridinoline (HP)] content by high-performance liquid chromatrography. Collagen content was not influenced by exercise or APAP ( P > 0.05). Compared with placebo, tendon water content was 7% ( P = 0.006, main effect) lower in animals consuming APAP (placebo: 54.79 ± 0.8%, APAP: 50.89 ± 1.2%). HP in the Achilles tendon was 36% greater (sedentary: 141 ± 15, exercise: 204 ± 26 mmol/mol collagen) in the exercise-trained rats independent of drug treatment ( P = 0.020, main effect). Independent of exercise, HP content was 33% lower ( P = 0.032, main effect) in the animals consuming APAP (placebo: 195 ± 21, APAP: 140 ± 19 mmol/mol collagen). Our data suggests that chronic consumption of APAP results in a reduction in collagen cross-linking and a loss of tissue water independent of chronic exercise. This reduction in cross-linking and water content could contribute to the decrease in tendon stiffness noted in humans chronically consuming APAP.

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Finite Element Analysis of Cushioned Diabetic Footwear Using Ethylene Vinyl Acetate Polymer

Polymers ◽

10.3390/polym13142261 ◽

2021 ◽

Vol 13 (14) ◽

pp. 2261

Author(s):

Mariyam J. Ghazali ◽

Xu Ren ◽

Armin Rajabi ◽

Wan Fathul Hakim W. Zamri ◽

Nadia Mohd Mustafah ◽

...

Keyword(s):

Finite Element ◽

Vinyl Acetate ◽

Diabetic Foot ◽

Plantar Pressure ◽

Ethylene Vinyl Acetate ◽

Foot Ulcers ◽

Diabetic Foot Ulcers ◽

Foot Pressure ◽

Treatment And Prevention ◽

Foot Model

With the development of societies, diabetic foot ulcers have become one of the most common diseases requiring lower extremity amputation. The early treatment and prevention of diabetic foot ulcers can considerably reduce the possibility of amputation. Using footwear to redistribute and relieve plantar pressure is one of the important measures for the treatment and prevention of diabetic foot ulcers. Thus, the evaluation and prediction of the distribution of plantar pressure play an important role in designing footwears. Herein, the finite element method was used to study plantar pressure under two kinds of foot models, namely, the skeletal structure foot model and the whole foot model, to explore the influence of human bones on the pressure of the soles of the feet and obtain accurate foot pressure. Simulation results showed that under the two models, the plantar pressure and the pressure from the footwear with ethylene vinyl acetate were all reduced. The total deformation demonstrated a slight increase. These stresses are very useful as they enable the design of suitable orthotic footwear that reduces the amount of stress in individuals with diabetic foot ulcers.

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Effectiveness of Pressure-Relieving Shoes/Insoles on Lowering the Plantar Pressure of Diabetic Foot: A Meta-Analysis

Leather and Footwear Journal ◽

10.24264/lfj.20.4.3 ◽

2020 ◽

Vol 20 (4) ◽

pp. 361-374

Author(s):

Xinrong ZHI ◽

Weiping WANG ◽

Bo XU ◽

Jin ZHOU

Keyword(s):

Diabetic Foot ◽

Plantar Pressure ◽

Meta Analysis ◽

Foot Ulcers ◽

Diabetic Patients ◽

Foot Care ◽

Custom Made ◽

Peak Plantar Pressure ◽

Pressure Concentration ◽

Set Up

Since current reports demonstrated a higher prevalence of foot ulcers in diabetic patients who suffer from foot complication, the preventing occurrence of foot ulcers were the primary target in foot care. Clinical consensus introduced a variety of pressure-relieving products to diabetic patients and clinicians prescribed these products to their patients and recommended them used in daily life. However, available data were still controversial and whether these products could effectively reduce plantar pressure or not were uncertain. Thereby, this meta-analysis aimed first to summary all relevant findings in current database and secondly to explore whether pressure-relieving insoles/shoes can really relieve plantar pressure and what’s differences between customized products (shoes/insoles) and standard ones in reducing plantar pressure. We first searched published articles cited from Web of Science, Medline via OVID, CINAHL, SCOPUS, INFORMIT, Cochrane Central and EMBASE via OVID. Then we filtered observational studies reporting experimental effect of pressure-relieving insoles/shoes. Meanwhile, we set up primary outcome as overall mean peak plantar pressure (MPP) and secondary outcomes as MPP at various plantar regions and MPP at insoles/shoes with various structure designs. Our results show that pressure-relieving products (shoes/insoles) did lower the amplitude of pressure concentration; effect of custom-made and pre-fabricated products on pressure-relieving were similar. These findings suggested that no matter pressure-relieving products were custom-made or prefabricated standard one, if they were designed targeting to increase overall plantar contact areas, such as designed based on plantar model, or to provide extra arch supports or plug-in structures to transfer pressure concentration, they were all useful in diabetic foot care to prevent occurrence of ulceration. Overall, it is recommended that diabetic patients shall wear pressure-relieving insoles/shoes while walking.

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Relationship between tendon structure, stiffness, gait patterns and patient reported outcomes during the early stages of recovery after an Achilles tendon rupture

Scientific Reports ◽

10.1038/s41598-020-77691-x ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Didier Laurent ◽

Lorcan Walsh ◽

Amir Muaremi ◽

Nicolau Beckmann ◽

Eckhard Weber ◽

...

Keyword(s):

Achilles Tendon ◽

Shear Wave ◽

Plantar Pressure ◽

Patient Reported Outcomes ◽

Clinical Decision Making ◽

Ex Vivo ◽

Achilles Tendon Rupture ◽

Tendon Stiffness ◽

Patient Reported ◽

The Impact

AbstractAfter an Achilles tendon (AT) injury, the decision to return to full weightbearing for the practice of sports or strenuous activities is based on clinical features only. In this study, tendon stiffness and foot plantar pressure, as objective quantitative measures that could potentially inform clinical decision making, were repeatedly measured in 15 patients until 3 months after the AT rupture by using shear wave elastography (SWE) and wearable insoles, respectively. Meanwhile, patient reported outcomes assessing the impact on physical activity were evaluated using the Achilles Tendon Total Rupture Score (ATRS). At week-2 post-injury, stiffness of the injured tendon varied from 6.00 ± 1.62 m/s (mean ± SD) close to the rupture to 8.91 ± 2.29 m/s when measured more distally. While near complete recovery was observed in distal and middle regions at week-8, the shear wave velocity in the proximal region recovered to only 65% of the contralateral value at week-12. In a parallel pre-clinical study, the tendon stiffness measured in vivo by SWE in a rat model was found to be strongly correlated with ex vivo values of the Young’s modulus, which attests to the adequacy of SWE for these measures. The insole derived assessment of the plantar pressure distribution during walking showed slight sub-optimal function of the affected foot at week-12, while the ATRS score recovered to a level of 59 ± 16. Significant correlations found between tendon stiffness, insole variables and distinct ATRS activities, suggest clinical relevance of tendon stiffness and foot plantar pressure measurements. These results illustrate how an alteration of the AT structure can impact daily activities of affected patients and show how digital biomarkers can track recovery in function over time.

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Image processing based foot plantar pressure distribution analysis and modeling

Indonesian Journal of Electrical Engineering and Computer Science ◽

10.11591/ijeecs.v17.i2.pp594-605 ◽

2020 ◽

Vol 17 (2) ◽

pp. 594

Author(s):

Ali Hussein Sabry ◽

W. Z. Wan Hasan ◽

Mohd Nazim Mohtar ◽

Raja Mohd Kamil Raja Ahmad ◽

Hafiz Rashidi Ramli ◽

...

Keyword(s):

Mathematical Modelling ◽

Plantar Pressure ◽

Pressure Level ◽

Diabetic Patients ◽

Distribution Analysis ◽

Foot Pressure ◽

Pressure System ◽

Pressure Distributions ◽

Plantar Pressure Distribution ◽

Pressure Analysis

<span lang="EN-GB">Although many equipments and techniques are available for plantar pressure analysis to study foot pressure distributions, there is still a need for mathematical modelling references to compare the acquired measurements. In order to derive formulas in this concern, this research proposes a measurement-based method which adopts the reference measured parameters such as; the weight of a subject, contact-area size, age, and the pressure level distribution over a plantar image captured by the EMED plantar pressure system. The proposed analysis and algorithm were verified by a group 79 volunteers through data collection with four various measurement conditions. Three mathematical modelling equations have been proposed that describe the relationships between the foot plantar pressure levels and the subject’s body mass, foot size, and age. The modelling of foot plantar pressure could be useful for various applications such as gait analysis, hospitals, clinics, custom shoe making, and early detection of ulceration in the case of diabetic patients.</span>

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EFFECT OF WEARING INSOLE WITH DIFFERENT DENSITY ON STANDING AND WALKING PLANTAR PRESSURE DISTRIBUTION

Journal of Mechanics in Medicine and Biology ◽

10.1142/s0219519419500064 ◽

2019 ◽

Vol 19 (03) ◽

pp. 1950006 ◽

Cited By ~ 1

Author(s):

NAHID TAFTI ◽

SAJJAD BAYAT TURK ◽

FATEMEH HEMMATI ◽

EHSAN NOROUZI ◽

KEYVAN SHARIFMORADI ◽

...

Keyword(s):

Diabetic Patient ◽

Pressure Distribution ◽

Plantar Pressure ◽

Pairwise Comparison ◽

Repeated Measure ◽

Diabetic Patients ◽

Foot Pressure ◽

Foot Ulceration ◽

Diabetic Ulcers ◽

Plantar Pressure Distribution

Diabetic ulcers can lead to infection and amputation. Using insole can help to reduce and prevent foot ulceration and amputation in a diabetic patient. The aim of this study was to analyze the effect of wearing an insole with different density on standing and walking plantar pressure distribution. Methods: A group of 10 diabetic patients participated in this one-grouped before-after trial. Plantar pressure distribution was measured during walking and standing. Repeated Measure was used to test differences. Results: Repeated measure test showed that use of insole decreased foot pressure while walking significantly ([Formula: see text]). Pairwise comparison showed that wearing shoe insole with shore 30 decreased pressure compared to wearing shoe insole with shore 50 ([Formula: see text]) and walking without insole respectively ([Formula: see text]). Conclusion: The insole has more effect on plantar pressure during walking than standing, it also concluded that insole with shore 30 decreased pressure during walking more than that of the insole with shore 50. It could be said that patients who suffer from pain and discomfort on hind and forefoot may benefit insole with shore 30 to relieve from plantar pressure on the hindfoot and forefoot regions during standing and walking.

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