title: Coronary flow reserve in patients with diabetes mellitus and prediabetes.
abstract: BACKGROUND
  Abnormalities of coronary microcirculation have been reported in patients with diabetes mellitus (DM) even in the presence of normal coronary arteries. It is unknown when the microvascular effects on coronary arteries begin to appear in the DM disease course. Coronary flow reserve (CFR), determined by pharmacological stress transthoracic Doppler echocardiography, is a reliable indicator of coronary microvascular function. We sought to determine the coronary microvascular function of prediabetic patients compared to DM patients and normal population.
  
  
  METHODS
  Seventy-four subjects with normal coronary arteries were enrolled. DM and prediabetes were diagnosed according to American Diabetes Association criteria. All subjects had Doppler recordings of the left anterior descending artery with adenosine infusion at a rate of 0.014 mg/kg per minute.
  
  
  RESULTS
  The demographical characteristics and laboratory findings of the three groups were similar (DM group: n = 25, mean age 62 ± 7 years, 19 females; prediabetic group: n = 25, mean age 64 ± 12 years, 21 females; control group: n = 24, mean age 63 ± 7 years, 15 females) except fasting glucose levels. CFR values of the three groups were significantly different (DM group: CFR = 1.75 ± 0.50; prediabetic group: CFR = 2.24 ± 0.43; control group: CFR = 2.38 ± 0.32, P < 0.001). CFR values of DM group were lower than those of prediabetic and control groups (DM vs. prediabetic: P < 0.001, DM vs. control: P < 0.001). However, CFR levels of prediabetic group were not different from those of the control group (P = 0.481). DM was an independent factor predictive of CFR < 2 (OR, 22.69; 95% CI, 6.47-79.51; P < 0.001).
  
  
  CONCLUSIONS
  Coronary microvascular function seems to be normal in the prediabetic state, but dysfunction appears after DM becomes overt.
authors.affiliation: Department of Cardiology, Fatih University School of Medicine, Ankara, Turkey. asliatar@gmail.com
authors.forename: Asli I
authors.initials: AI
authors.lastname: Atar
authors.forename: Tugba Kayhan
authors.initials: TK
authors.lastname: Altuner
authors.forename: Huseyin
authors.initials: H
authors.lastname: Bozbas
authors.forename: Mehmet E
authors.initials: ME
authors.lastname: Korkmaz
mesh_terms: D023921:Coronary Stenosis / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology*; D048909:Diabetes Complications / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology*; D003920:Diabetes Mellitus / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D005260:Female; D053805:Fractional Flow Reserve, Myocardial; D006801:Humans; D008297:Male; D008875:Middle Aged; D014463:Ultrasonography