The association between mechanical and biochemical/histological characteristics in diabetic and non-diabetic plantar soft tissue.
Diabetes, and the subsequent complication of lower limb ulcers leading to potential amputation, remains an important health care problem in United States, even with declining amputation rates. It has been well documented that diabetes can alter the mechanical properties (i.e., increased stiffness) of the plantar soft tissue, although this finding is not universal. Similarly, biochemical, and histological changes have been found in the plantar soft tissue, but, as with the mechanical changes, these findings are not consistent across all studies. Our group׳s work has demonstrated that diabetes increases plantar soft tissue modulus and increases elastic septal thickness. The purpose of the current study was to explore the association between mechanical, biochemical and histological properties. Using previously collected data, a linear mixed effects regression was conducted. The correlations were weak; of the 32 that were tested, only 3 (modulus to septal thickness when location was accounted for, energy loss to total collagen, and energy loss to collagen/elastin ratio) were statistically significant, none with an R2greater than 0.10. The main differences in the means were increased tissue stiffness and increased septal wall thickness, both trends were supported in the literature. However, as the correlations were weak, it is likely that another unexamined biochemical factor (perhaps collagen crosslinking) is associated with the mechanical tissue changes.
VA RR&D Center of Excellence for Limb Loss Prevention and Prosthetic Engineering, Seattle, WA 98108, United States; Departments of Mechanical Engineering, University of Washington, Seattle, WA 98195, United States; Department of Orthopaedics & Sports Medicine, University of Washington, Seattle, WA 98195, United States. Electronic address: wrledoux@uw.edu.
William R
WR
Ledoux
VA RR&D Center of Excellence for Limb Loss Prevention and Prosthetic Engineering, Seattle, WA 98108, United States; Departments of Mechanical Engineering, University of Washington, Seattle, WA 98195, United States.
Shruti
S
Pai
VA RR&D Center of Excellence for Limb Loss Prevention and Prosthetic Engineering, Seattle, WA 98108, United States.
Jane B
JB
Shofer
VA RR&D Center of Excellence for Limb Loss Prevention and Prosthetic Engineering, Seattle, WA 98108, United States; Applied Physics Laboratory, University of Washington, Seattle, WA 98195, United States.
Yak-Nam
YN
Wang
D000368:Aged; D001696:Biomechanical Phenomena; D003094:Collagen / Q000378:metabolism; D017719:Diabetic Foot / Q000378:metabolism* / Q000473:pathology* / Q000503:physiopathology; D005260:Female; D005528:Foot / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D008297:Male; D055595:Mechanical Phenomena
D003094:Collagen
Adipose; Diabetes; Foot; Plantar soft tissue; Subcutaneous; Ulceration