title: Relationship between HbA₁c and coronary flow rate in patients with type 2 diabetes mellitus and angiographically normal coronary arteries.
abstract: OBJECTIVE
  We examined the relationship between glycosylated hemoglobin (HbA1c) level and coronary flow rate in patients with type 2 diabetes mellitus (DM) and angiographically normal coronary arteries.
  
  
  METHODS
  The study included 54 consecutive patients (36 males, 18 females; age range 37 to 72 years) with type 2 DM, whose coronary arteries were found normal on coronary angiography. All patients underwent echocardiography and plasma HbA1c levels were measured before coronary angiography. To determine slow coronary flow (SCF), coronary flow rates of the left anterior descending (LAD), circumflex (Cx), and right coronary (RCA) arteries were assessed using the TIMI frame count (TFC) method.
  
  
  RESULTS
  None of the patients had echocardiographic abnormalities. The mean HbA1c level was 7.4±2.0%, and the mean TFCs were 34.3±6.5, 22.4±3.5, and 20.4±2.2 for the LAD, Cx, and RCA, respectively. HbA1c levels were <7% in 26 patients, and ≥7% in 28 patients. Thirty-eight patients (70.4%) were found to have SCF in at least one coronary artery. TIMI frame counts of all three coronary arteries were significantly greater in patients in whom HbA1c was ≥7% (p<0.001). TIMI frame counts showed significant correlations with the HbA1c level (LAD: r=0.782; Cx: r=0.707; RCA: r=0.515; p<0.001 for all). The mean HbA1c level was significantly higher in patients with SCF compared to patients without SCF (7.8±1.9% vs. 5.6±0.9%; p<0.001). The incidence of SCF was significantly greater in patients with HbA1c ≥7.0% than those with HbA1c <7.0% (96.4% vs. 61.5%; p=0.004). Increased HbA1c (≥7%) significantly increased the risk for SCF in at least one coronary artery (OR=16.875; 95% CI 1.972-144.38).
  
  
  CONCLUSIONS
  Our findings suggest that there is a strong correlation between the HbA1c level and coronary flow rate.
authors.affiliation: Department of Cardiology, Medicine Faculty of Cumhuriyet University, Sivas, Turkey.
authors.forename: Mehmet Birhan
authors.initials: MB
authors.lastname: Yılmaz
authors.forename: Alim
authors.initials: A
authors.lastname: Erdem
authors.forename: Osman Can
authors.initials: OC
authors.lastname: Yontar
authors.forename: Savaş
authors.initials: S
authors.lastname: Sarıkaya
authors.forename: Ahmet
authors.initials: A
authors.lastname: Yılmaz
authors.forename: Nihat
authors.initials: N
authors.lastname: Madak
authors.forename: Filiz
authors.initials: F
authors.lastname: Karadaş
authors.forename: Izzet
authors.initials: I
authors.lastname: Tandoğan
mesh_terms: D000328:Adult; D000368:Aged; D001783:Blood Flow Velocity / Q000502:physiology; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging; D003326:Coronary Circulation / Q000502:physiology*; D003331:Coronary Vessels / Q000000981:diagnostic imaging; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism / Q000503:physiopathology*; D004452:Echocardiography; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis* / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged
chemical_list: D006442:Glycated Hemoglobin