title: Acute hyperglycemia does not affect the reactivity of coronary microcirculation in humans.
abstract: OBJECTIVE
  There is some evidence that acute hyperglycemia (H) may cause vascular dysfunction in normal subjects. This study investigates whether acute, short-term H affects coronary vasodilatory function in healthy subjects.
  
  
  METHODS
  Diastolic peak flow velocity in the left anterior descending coronary artery was measured at rest and after dipyridamole (0.56 mg/kg over 4 min) using transthoracic color Doppler echocardiography in 13 healthy men. Coronary flow reserve (CFR) was defined as the ratio of dipyridamole-induced coronary peak diastolic to resting peak diastolic flow velocity. CFR was measured both in euglycemia (E) and after 3 h H ( approximately 14 mmol/liter) by a variable infusion of glucose and octreotide (0.4 mg/h) to prevent increase in insulin concentration.
  
  
  RESULTS
  Fasting plasma glucose increased to 14.3 +/- 0.33 mmol/liter during the study and maintained variability within less than 10%. Plasma insulin remained nearly stable during H. Resting diastolic flow velocity was 18.5 +/- 0.6 cm/sec in E and increased to 20.0 +/- 0.7 cm/sec during H (P < 0.005). Dipyridamole infusion produced a marked increase in coronary flow velocity, which reached values of 50.8 +/- 2.9 cm/sec in E and 51.8 +/- 2.1 cm/sec in H (P = not significant). CFR was 2.78 +/- 0.16 in E and 2.59 +/- 0.12 in H (P = not significant).
  
  
  CONCLUSIONS
  Our study indicates that short-term hyperglycemia does not affect the vasodilatory response of coronary microcirculation in healthy subjects.
authors.affiliation: Department of Clinical and Experimental Medicine, University Federico II, Naples, Italy. bcapaldo@unina.it
authors.forename: Brunella
authors.initials: B
authors.lastname: Capaldo
authors.forename: Maurizio
authors.initials: M
authors.lastname: Galderisi
authors.forename: Anna Amelia
authors.initials: AA
authors.lastname: Turco
authors.forename: Arcangelo
authors.initials: A
authors.lastname: D'Errico
authors.forename: Salvatore
authors.initials: S
authors.lastname: Turco
authors.forename: Angela Albarosa
authors.initials: AA
authors.lastname: Rivellese
authors.forename: Giovanni
authors.initials: G
authors.lastname: de Simone
authors.forename: Oreste
authors.initials: O
authors.lastname: de Divitiis
authors.forename: Gabriele
authors.initials: G
authors.lastname: Riccardi
mesh_terms: D000208:Acute Disease; D000328:Adult; D003326:Coronary Circulation / Q000187:drug effects; D004176:Dipyridamole / Q000494:pharmacology; D004452:Echocardiography; D006801:Humans; D006943:Hyperglycemia / Q000503:physiopathology*; D008297:Male; D008833:Microcirculation / Q000187:drug effects
chemical_list: D004176:Dipyridamole