title: Redistribution of blood volume in type I diabetes.
abstract: OBJECTIVE
  Impaired activity of endothelium-derived nitric oxide in Type I (insulin-dependent) diabetes mellitus will cause an increased vascular tone. Considering the lower production of nitric oxide in veins than in arteries, an impaired activity would have less vasoconstrictive effect in veins. The reported minimally changed total plasma volume in diabetes might, therefore, indicate a redistribution of blood volumes from the arterial to the venous side of the circulation. This could be more pronounced in patients with microalbuminuria.
  
  
  METHODS
  In 16 normoalbuminuric and 16 microalbuminuric Type I diabetic patients and 16 individually matched healthy control subjects, venous and arterial blood volumes, venous myogenic response and arterial distensibilities were assessed in the upper arm using an electrical bio-impedance method.
  
  
  RESULTS
  In diabetic patients, the venous blood volume and venous myogenic response were increased (p < 0.02 and p < 0.05, respectively), whereas the arterial blood volume did not change. Moreover, in diabetic patients the distensibility of the large arteries was decreased (p < 0.05) but increased in the total arterial bed (p < 0.05). Therefore, the distensibility of the small arteries must have been increased. No differences were found between normoalbuminuric and microalbuminuric diabetic patients.
  
  
  CONCLUSIONS
  The increase in venous blood volume and myogenic response and the decrease in distensibility of the large arteries in the upper arm are in agreement with the expected shift towards venous blood volume distribution in Type I diabetes with and without microalbuminuria. Furthermore, they support the haemodynamic hypothesis of the pathogenesis of diabetic microangiopathy.
authors.affiliation: Department of Internal Medicine, University Hospital Groningen, P.O. Box 30.001, 9700 RB Groningen, The Netherlands.
authors.forename: F L
authors.initials: FL
authors.lastname: Ubels
authors.forename: J H
authors.initials: JH
authors.lastname: Muntinga
authors.forename: T P
authors.initials: TP
authors.lastname: Links
authors.forename: K
authors.initials: K
authors.lastname: Hoogenberg
authors.forename: R P
authors.initials: RP
authors.lastname: Dullaart
authors.forename: W D
authors.initials: WD
authors.lastname: Reitsma
authors.forename: A J
authors.initials: AJ
authors.lastname: Smit
mesh_terms: D000328:Adult; D000419:Albuminuria / Q000503:physiopathology; D001132:Arm / Q000098:blood supply; D001158:Arteries; D001810:Blood Volume; D003922:Diabetes Mellitus, Type 1 / Q000503:physiopathology* / Q000652:urine; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D014680:Veins