title: Human Achilles tendon glycation and function in diabetes.
abstract: 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.
authors.affiliation: IOC Sports Medicine, Department of Orthopedic Surgery M, Bispebjerg Hospital and Center for Healthy Aging, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark; Department of Physical Therapy, Musculoskeletal Rehabilitation Research Unit, Bispebjerg Hospital, Copenhagen, Denmark; ccouppe@gmail.com.
authors.forename: Christian
authors.initials: C
authors.lastname: Couppé
authors.affiliation: IOC Sports Medicine, Department of Orthopedic Surgery M, Bispebjerg Hospital and Center for Healthy Aging, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark;
authors.forename: Rene Brüggebusch
authors.initials: RB
authors.lastname: Svensson
authors.affiliation: IOC Sports Medicine, Department of Orthopedic Surgery M, Bispebjerg Hospital and Center for Healthy Aging, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark;
authors.forename: Mads
authors.initials: M
authors.lastname: Kongsgaard
authors.affiliation: Department of Health Sciences, University of Jyväskylä, Jyväskylä, Finland;
authors.forename: Vuokko
authors.initials: V
authors.lastname: Kovanen
authors.affiliation: CNRS UMR 7338, Biomécanique et Bioingénierie, Université de Technologie de Compiègne, Compiègne, France; Université Paris 13, Sorbonne Paris Cité, UFR Santé Médecine et Biologie Humaine, Paris, France;
authors.forename: Jean-Francois
authors.initials: JF
authors.lastname: Grosset
authors.affiliation: Department of Endocrinology, Hvidovre University Hospital, Hvidovre, Denmark;
authors.forename: Ole
authors.initials: O
authors.lastname: Snorgaard
authors.affiliation: Gait Analysis Laboratory, Department of Orthopaedics, Copenhagen University Hospital, Hvidovre, Denmark;
authors.forename: Jesper
authors.initials: J
authors.lastname: Bencke
authors.affiliation: Department of Neuroscience and Pharmacology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark;
authors.forename: Jytte Overgaard
authors.initials: JO
authors.lastname: Larsen
authors.affiliation: Physical Medicine and Rehabilitation Research-Copenhagen, Department of Physical Therapy, Copenhagen, Denmark; Department of Orthopedic Surgery, Hvidovre Hospital, University of Copenhagen, Hvidovre, Denmark; Clinical Research Centre, Hvidovre Hospital, University of Copenhagen, Hvidovre, Denmark;
authors.forename: Thomas
authors.initials: T
authors.lastname: Bandholm
authors.affiliation: Department of Endocrinology, Bispebjerg Hospital, Copenhagen, Denmark; and.
authors.forename: Tomas Møller
authors.initials: TM
authors.lastname: Christensen
authors.affiliation: IOC Sports Medicine, Department of Orthopedic Surgery M, Bispebjerg Hospital and Center for Healthy Aging, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark;
authors.forename: Anders
authors.initials: A
authors.lastname: Boesen
authors.affiliation: IOC Sports Medicine, Department of Orthopedic Surgery M, Bispebjerg Hospital and Center for Healthy Aging, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark;
authors.forename: Ida Carøe
authors.initials: IC
authors.lastname: Helmark
authors.affiliation: Institute of Sports Science and Clinical Biomechanics, SDU Muscle Research Cluster, University of Southern Denmark, Odense, Denmark.
authors.forename: Per
authors.initials: P
authors.lastname: Aagaard
authors.affiliation: IOC Sports Medicine, Department of Orthopedic Surgery M, Bispebjerg Hospital and Center for Healthy Aging, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark;
authors.forename: Michael
authors.initials: M
authors.lastname: Kjaer
authors.affiliation: IOC Sports Medicine, Department of Orthopedic Surgery M, Bispebjerg Hospital and Center for Healthy Aging, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark; Department of Physical Therapy, Musculoskeletal Rehabilitation Research Unit, Bispebjerg Hospital, Copenhagen, Denmark;
authors.forename: Stig Peter
authors.initials: SP
authors.lastname: Magnusson
mesh_terms: D000125:Achilles Tendon / Q000503:physiopathology*; D001696:Biomechanical Phenomena / Q000502:physiology; D001786:Blood Glucose / Q000502:physiology; D003430:Cross-Sectional Studies; D003920:Diabetes Mellitus / Q000503:physiopathology*; D005528:Foot / Q000502:physiology; D005684:Gait / Q000502:physiology; D038321:Glycemic Index / Q000502:physiology*; D006031:Glycosylation; D006801:Humans; D008297:Male; D008875:Middle Aged
chemical_list: D001786:Blood Glucose
keywords: Achilles tendon mechanics; diabetes; enzymatic and nonenzymatic collagen cross-linking; foot ulcer