title: Impact of vitamin D insufficiency on the epicardial coronary flow velocity and endothelial function.
abstract: OBJECTIVE
  Increasing evidence suggests a relationship between vitamin D (VD) insufficiency and cardiovascular disease. The present study evaluated the effect of VD insufficiency on epicardial coronary flow rate, subclinical atherosclerosis, and endothelial function.
  
  
  METHODS
  The present study was cross-sectional and observational. We enrolled 222 consecutive patients who had undergone coronary angiography for suspected ischemic heart disease and were found to have normal or near-normal coronary arteries. Thereafter, 25(OH)D3 levels were measured and the coronary flow rate was assessed using the thrombolysis in myocardial infarction frame count. Slow coronary flow (SCF) was defined as a thrombolysis in myocardial infarction frame count greater than 27/frame. Endothelial function was assessed by brachial artery flow-mediated dilatation. Carotid intima-media thickness, an indicator of subclinical atherosclerosis, was measured using B-mode ultrasonography.
  
  
  RESULTS
  The mean level of 25(OH)D3 was 31.8 ng/ml, and 47% (n=106) of the patients had insufficient 25(OH)D levels (<30 ng/ml). Baseline characteristics were similar between VD-insufficient and VD-sufficient groups. The incidence of SCF was significantly higher in the VD-insufficient group than in patients with sufficient VD (relative risk=3.5, 95% confidence interval=1.1-10.5, P=0.01). After adjusting for cardiovascular disease risk factors, VD insufficiency was independently associated with SCF. The linear regression analysis showed that VD insufficiency was correlated independently with % flow-mediated dilatation (β=0.424, P<0.001) and carotid intima-media thickness (β=0.43, P<0.001).
  
  
  CONCLUSIONS
  A strong association was found between VD insufficiency and the SCF phenomenon. In addition, VD insufficiency was associated with endothelial dysfunction and subclinical atherosclerosis. We believe that further studies are required to clarify the role of VD in patients with SCF.
authors.affiliation: Department of Cardiology, Istanbul School of Medicine, Istanbul University, Istanbul, Turkey. fahrettin_oz@hotmail.com
authors.forename: Fahrettin
authors.initials: F
authors.lastname: Oz
authors.forename: Ahmet Y
authors.initials: AY
authors.lastname: Cizgici
authors.forename: Huseyin
authors.initials: H
authors.lastname: Oflaz
authors.forename: Ali
authors.initials: A
authors.lastname: Elitok
authors.forename: Ekrem B
authors.initials: EB
authors.lastname: Karaayvaz
authors.forename: Fehmi
authors.initials: F
authors.lastname: Mercanoglu
authors.forename: Zehra
authors.initials: Z
authors.lastname: Bugra
authors.forename: Beyhan
authors.initials: B
authors.lastname: Omer
authors.forename: Kamil
authors.initials: K
authors.lastname: Adalet
authors.forename: Aytac
authors.initials: A
authors.lastname: Oncul
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D001783:Blood Flow Velocity; D001916:Brachial Artery / Q000503:physiopathology; D002112:Calcifediol / Q000097:blood; D002318:Cardiovascular Diseases / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D002340:Carotid Artery Diseases / Q000175:diagnosis / Q000209:etiology; D059168:Carotid Intima-Media Thickness; D016009:Chi-Square Distribution; D017023:Coronary Angiography; D003326:Coronary Circulation; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000503:physiopathology*; D003430:Cross-Sectional Studies; D004730:Endothelium, Vascular / Q000503:physiopathology*; D005260:Female; D006801:Humans; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010496:Pericardium; D011237:Predictive Value of Tests; D012039:Regional Blood Flow; D012307:Risk Factors; D014808:Vitamin D Deficiency / Q000097:blood / Q000150:complications* / Q000503:physiopathology
chemical_list: D015415:Biomarkers; D002112:Calcifediol