title: Insulin-induced microvascular recruitment in skin and muscle are related and both are associated with whole-body glucose uptake.
abstract: OBJECTIVE
  Insulin-induced capillary recruitment is considered a determinant of insulin-mediated glucose uptake. Insulin action on the microvasculature has been assessed in skin; however, there is concern as to whether the vascular responses observed in skin reflect those in the muscle. We hypothesized that insulin-induced capillary recruitment in skin would correlate with microvascular recruitment in muscle in a group of subjects displaying a wide variation in insulin sensitivity.
  
  
  METHODS
  Capillary recruitment in skin was assessed using capillary videomicroscopy, and skeletal muscle microvascular recruitment (i.e., increase in MBV) was studied using CEU in healthy volunteers (n = 18, mean age: 30.6 ± 11.1 years). Both microvascular measurements were performed during saline infusion, and during a hyperinsulinemic euglycemic clamp.
  
  
  RESULTS
  During hyperinsulinemia, capillary recruitment in skin was augmented from 58.1 ± 18.2% to 81.0 ± 23.9% (p < 0.0001). Hyperinsulinemia increased MBV in muscle from 7.00 (2.66-17.67) to 10.06 (2.70-41.81) units (p = 0.003). Insulin's vascular effect in skin and muscle was correlated (r = 0.57). Insulin's microvascular effects in skin and muscle showed comparable strong correlations with insulin-mediated glucose uptake (r = 0.73 and 0.68, respectively).
  
  
  CONCLUSIONS
  Insulin-augmented capillary recruitment in skin parallels insulin-mediated microvascular recruitment in muscle and both are related to insulin-mediated glucose uptake.
authors.affiliation: Department of Internal Medicine and the Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Rick I
authors.initials: RI
authors.lastname: Meijer
authors.forename: Michiel P
authors.initials: MP
authors.lastname: De Boer
authors.forename: Martine R
authors.initials: MR
authors.lastname: Groen
authors.forename: Etto C
authors.initials: EC
authors.lastname: Eringa
authors.forename: Stephen
authors.initials: S
authors.lastname: Rattigan
authors.forename: Eugene J
authors.initials: EJ
authors.lastname: Barrett
authors.forename: Yvo M
authors.initials: YM
authors.lastname: Smulders
authors.forename: Erik H
authors.initials: EH
authors.lastname: Serne
mesh_terms: D000328:Adult; D002196:Capillaries / Q000378:metabolism / Q000503:physiopathology*; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D006946:Hyperinsulinism / Q000139:chemically induced / Q000378:metabolism / Q000503:physiopathology; D007004:Hypoglycemic Agents / Q000009:adverse effects* / Q000494:pharmacology; D007328:Insulin / Q000009:adverse effects* / Q000494:pharmacology; D008297:Male; D008833:Microcirculation / Q000187:drug effects; D018482:Muscle, Skeletal / Q000098:blood supply / Q000378:metabolism / Q000503:physiopathology; D012867:Skin / Q000098:blood supply / Q000378:metabolism / Q000503:physiopathology
chemical_list: D007004:Hypoglycemic Agents; D007328:Insulin; D005947:Glucose