title: Effects of type 2 diabetes mellitus on coronary microvascular function and myocardial perfusion in patients without obstructive coronary artery disease.
abstract: OBJECTIVE
  We assessed the impact of type 2 diabetes, in the presence of other major cardiovascular risk factors, on coronary microvascular function and myocardial perfusion in patients without obstructive coronary artery disease (CAD).
  
  
  METHODS
  In this prospective study, 23 patients with type 2 diabetes and 26 nondiabetic patients matched for age, sex and other cardiovascular risk factors underwent a cold pressure test (CPT) and dipyridamole transthoracic echocardiography to determine their coronary flow (CF) ratio. Within 2 weeks, all diabetic patients also underwent dipyridamole-rest myocardial perfusion single-photon emission (MPS) CT. None of the patients with or without diabetes had significant CAD on invasive coronary angiography.
  
  
  RESULTS
  The CPT-CF ratio was significantly lower in diabetic patients than in nondiabetic patients (1.46 ± 0.26 vs. 1.71 ± 0.32, p = 0.006) and was correlated significantly with fasting glycaemia (r = -0.35, p = 0.01), but not with glycated haemoglobin. The dipyridamole-CF ratio was also lower in diabetic patients than in nondiabetic patients (2.38 ± 0.74 vs. 2.75 ± 0.49, p = 0.04). On MPS imaging, 5 diabetic patients (22%) had stress-induced ischaemia and the remaining 18 (78%) had normal myocardial perfusion. The dipyridamole-CF ratio was not different in patients with and without reversible defects (2.3 ± 1.1 vs. 2.4 ± 0.6, p = 0.97).
  
  
  CONCLUSIONS
  Coronary microvascular function is impaired in type 2 diabetic patients without significant CAD, compared to nondiabetic patients with similar other cardiovascular risk factors. In the majority of diabetic patients, microvascular dysfunction is associated with normal myocardial perfusion.
authors.affiliation: Department of Clinical Medicine, Cardiovascular and Immunological Sciences, University Federico II, Napoli, Italy.
authors.forename: Caterina
authors.initials: C
authors.lastname: Marciano
authors.forename: Maurizio
authors.initials: M
authors.lastname: Galderisi
authors.forename: Paola
authors.initials: P
authors.lastname: Gargiulo
authors.forename: Wanda
authors.initials: W
authors.lastname: Acampa
authors.forename: Carmen
authors.initials: C
authors.lastname: D'Amore
authors.forename: Roberta
authors.initials: R
authors.lastname: Esposito
authors.forename: Enza
authors.initials: E
authors.lastname: Capasso
authors.forename: Gianluigi
authors.initials: G
authors.lastname: Savarese
authors.forename: Laura
authors.initials: L
authors.lastname: Casaretti
authors.forename: Francesco
authors.initials: F
authors.lastname: Lo Iudice
authors.forename: Giovanni
authors.initials: G
authors.lastname: Esposito
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Rengo
authors.forename: Dario
authors.initials: D
authors.lastname: Leosco
authors.forename: Alberto
authors.initials: A
authors.lastname: Cuocolo
authors.forename: Pasquale
authors.initials: P
authors.lastname: Perrone-Filardi
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D003326:Coronary Circulation / Q000502:physiology; D003327:Coronary Disease / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology*; D003924:Diabetes Mellitus, Type 2 / Q000473:pathology / Q000503:physiopathology*; D003925:Diabetic Angiopathies / Q000503:physiopathology*; D004176:Dipyridamole; D015150:Echocardiography, Doppler; D005260:Female; D006801:Humans; D008297:Male; D055806:Microvessels / Q000000981:diagnostic imaging / Q000473:pathology; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology*; D055414:Myocardial Perfusion Imaging / Q000379:methods; D011446:Prospective Studies; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods
chemical_list: D004176:Dipyridamole; D017256:Technetium Tc 99m Sestamibi