title: Skeletal muscle capillary density and microvascular function are compromised with aging and type 2 diabetes.
abstract: Adequate muscle perfusion is required for the maintenance of skeletal muscle mass. Impairments in microvascular structure and/or function with aging and type 2 diabetes have been associated with the progressive loss of skeletal muscle mass. Our objective was to compare muscle fiber type specific capillary density and endothelial function between healthy young men, healthy older men, and age-matched type 2 diabetes patients. Fifteen healthy young men (24 ± 1 yr), 15 healthy older men (70 ± 2 yr), and 15 age-matched type 2 diabetes patients (70 ± 1 yr) were selected to participate in the present study. Whole body insulin sensitivity, muscle fiber type specific capillary density, sublingual microvascular density, and dimension of the erythrocyte-perfused boundary region were assessed to evaluate the impact of aging and/or type 2 diabetes on microvascular structure and function. Whole body insulin sensitivity was significantly lower at a more advanced age, with lowest values reported in the type 2 diabetic patients. In line, skeletal muscle capillary contacts were much lower in the older and older type 2 diabetic patients when compared with the young. Sidestream darkfield imaging showed a significantly greater thickness of the erythrocyte perfused boundary region in the type 2 diabetic patients compared with the young. Skeletal muscle capillary density is reduced with aging and type 2 diabetes and accompanied by impairments in endothelial glycocalyx function, which is indicative of compromised vascular function.
authors.affiliation: Department of Human Movement Sciences, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Centre+, Maastricht, The Netherlands.
authors.forename: Bart B L
authors.initials: BB
authors.lastname: Groen
authors.forename: Henrike M
authors.initials: HM
authors.lastname: Hamer
authors.forename: Tim
authors.initials: T
authors.lastname: Snijders
authors.forename: Janneau
authors.initials: J
authors.lastname: van Kranenburg
authors.forename: Dionne
authors.initials: D
authors.lastname: Frijns
authors.forename: Hans
authors.initials: H
authors.lastname: Vink
authors.forename: Luc J C
authors.initials: LJ
authors.lastname: van Loon
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000473:pathology* / Q000502:physiology*; D002196:Capillaries / Q000473:pathology / Q000503:physiopathology; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000473:pathology* / Q000503:physiopathology*; D004730:Endothelium, Vascular / Q000473:pathology / Q000503:physiopathology; D005951:Glucose Tolerance Test; D006442:Glycated Hemoglobin / Q000378:metabolism; D019276:Glycocalyx / Q000473:pathology / Q000502:physiology; D006801:Humans; D007333:Insulin Resistance; D008297:Male; D055806:Microvessels / Q000473:pathology / Q000503:physiopathology; D018482:Muscle, Skeletal / Q000098:blood supply*; D055815:Young Adult
chemical_list: D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human
keywords: SDF technology; glucose; insulin; muscle; vascularization