title: Endothelial function in patients with type 1 diabetes evaluated by skin capillary recruitment.
abstract: The aim of the present study was to evaluate skin capillary density and recruitment of the upper and lower extremities of patients with type 1 diabetes under chronic treatment without clinical manifestations of diabetes-related complications. This cross-sectional observational study included 59 (27.1+/-10.6 years) consecutive outpatients with type 1 diabetes [duration 10 (1; 45) years] and 41 age- and sex-matched healthy controls. We used intravital video-microscopy to measure basal and maximal (during venous congestion) skin capillary densities as well as capillary recruitment using post-occlusive reactive hyperemia (PORH) in the dorsum of the fingers and toes. Mean capillary density (MCD) of the fingers at baseline was not different between controls and patients (123.02+/-22.6 and 132.3+/-28.9 capillaries/mm(2), respectively; P=0.08). In contrast, baseline MCD of the toes was lower in controls, when compared to patients (84.6+/-19.8 and 96.2+/-23.4 capillaries/mm(2), respectively; P=0.01). Capillary recruitment during PORH (% increase of the number of capillaries/mm(2)) was significantly higher in controls compared to patients both in fingers [7 (-8; 33) and -1.0 (-35, 13), respectively; P=0.000] and toes [6 (-20; 46) and 0 (-24; 20), respectively; P=0.000]. During venous occlusion, capillary density increase (% increase of the number of capillaries/mm(2)) was also higher in controls compared to patients both in fingers [3 (-14; 23) and 0.0 (-30; 29.2), respectively; P=0.02] and toes [9.3 (-18; 51) and -7 (-34; 22), respectively; P=0.000]. Our results showed that patients with type 1 diabetes, although not presenting skin capillary rarefaction, display skin microvascular functional alterations in both extremities characterized by an absence of capillary reserve.
authors.affiliation: Department of Medicine, Diabetes Unit, State University of Rio de Janeiro, Brazil. etibi@ioc.fiocruz.br
authors.forename: E
authors.initials: E
authors.lastname: Tibiriçá
authors.forename: E
authors.initials: E
authors.lastname: Rodrigues
authors.forename: R A
authors.initials: RA
authors.lastname: Cobas
authors.forename: M B
authors.initials: MB
authors.lastname: Gomes
mesh_terms: D000328:Adult; D002196:Capillaries / Q000503:physiopathology; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D003922:Diabetes Mellitus, Type 1 / Q000503:physiopathology*; D004730:Endothelium, Vascular / Q000503:physiopathology*; D005260:Female; D005385:Fingers / Q000098:blood supply; D006801:Humans; D006940:Hyperemia / Q000503:physiopathology; D008297:Male; D018715:Microscopy, Video; D012867:Skin / Q000098:blood supply; D014034:Toes / Q000098:blood supply