title: Retinopathy identifies marked restriction of coronary flow reserve in patients with diabetes mellitus.
abstract: OBJECTIVE
  This study sought to assess the differences in coronary flow reserve in patients with and without diabetic retinopathy.
  
  
  BACKGROUND
  Microvascular abnormalities throughout the body and impairment of coronary flow reserve have been described in patients with diabetes mellitus. However, the relation between diabetic retinopathy and coronary microvascular disease has not been investigated.
  
  
  METHODS
  The study included 29 patients with diabetes mellitus (18 with and 11 without diabetic retinopathy) and 15 control patients with chest pain and normal coronary arteries. Diabetic retinopathy was nonproliferative in all 18 patients with this disorder (8 had background, 10 preproliferative retinopathy). Five minutes after injection of 3 mg of isosorbide dinitrate, phasic flow velocities were recorded in the proximal segment of the angiographically normal left anterior descending coronary artery at rest and during hyperemia (0.14 mg/kg body weight per min of adenosine infused intravenously) using a 0.014-in. 15-MHz Doppler guide wire. Coronary blood flow was calculated, and coronary flow reserve was obtained from the hyperemic/baseline flow ratio.
  
  
  RESULTS
  Coronary blood flow was significantly lower during hyperemia ([mean +/- SD] 107 +/- 23 and 116 +/- 18 vs. 136 +/- 17 ml/min, respectively) and higher at baseline (58 +/- 16 and 45 +/- 12 vs. 37 +/- 10 ml/min, respectively) in diabetic patients with and without retinopathy than in control subjects (p < 0.05 for both diabetic groups). As a result, coronary flow reserve in both groups of diabetic patients was significantly lower than in control patients (1.9 +/- 0.4 and 2.8 +/- 0.3 vs. 3.3 +/- 0.4, respectively, p < 0.01 for both diabetic groups), and its reduction was greater in patients with than without retinopathy (p < 0.01). Furthermore, in patients with diabetic retinopathy, maximal hyperemic coronary flow (102 +/- 11 vs. 114 +/- 16 ml/min, p < 0.05) and flow reserve (1.6 +/- 0.2 vs. 2.3 +/- 0.2, p < 0.01) were significantly lower in those with preproliferative than background retinopathy.
  
  
  CONCLUSIONS
  Coronary flow reserve is significantly restricted in patients with diabetes mellitus, and its reduction is more marked in those with diabetic retinopathy, especially in advanced retinopathy. Thus, diabetic retinopathy should identify marked restriction of coronary flow reserve in patients with diabetes mellitus.
authors.affiliation: Department of Cardiology, Kobe General Hospital, Japan. jse@warp.or.jp
authors.forename: T
authors.initials: T
authors.lastname: Akasaka
authors.forename: K
authors.initials: K
authors.lastname: Yoshida
authors.forename: T
authors.initials: T
authors.lastname: Hozumi
authors.forename: T
authors.initials: T
authors.lastname: Takagi
authors.forename: S
authors.initials: S
authors.lastname: Kaji
authors.forename: T
authors.initials: T
authors.lastname: Kawamoto
authors.forename: S
authors.initials: S
authors.lastname: Morioka
authors.forename: J
authors.initials: J
authors.lastname: Yoshikawa
mesh_terms: D000328:Adult; D000368:Aged; D001783:Blood Flow Velocity / Q000187:drug effects; D006328:Cardiac Catheterization; D016022:Case-Control Studies; D003326:Coronary Circulation / Q000187:drug effects; D003327:Coronary Disease / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology*; D048909:Diabetes Complications; D003930:Diabetic Retinopathy / Q000150:complications*; D015150:Echocardiography, Doppler; D005260:Female; D006801:Humans; D007548:Isosorbide Dinitrate / Q000494:pharmacology; D008297:Male; D008833:Microcirculation / Q000187:drug effects; D008875:Middle Aged; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D014665:Vasodilator Agents; D007548:Isosorbide Dinitrate