title: Time-Course Analysis of Flow Mediated Dilation for the Evaluation of Endothelial Function After a High-Fat Meal in African Americans.
abstract: BACKGROUND
  Flow-mediated dilation (FMD) is used to assess endothelial function through changes in vascular diameter after hyperemia. High-fat meal (HFM) has been shown to induce endothelial dysfunction; recent studies, however, reported conflicting results in obese African American women (AAW). Differences in the method used to analyze FMD may explain these discrepancies.
  
  
  RESULTS
  In protocol 1, we assessed the time course of FMD and compared the repeatability of FMD using the individual maximum peak dilation (FMDpeak) and the dilation at 60 seconds (FMD60). Sixteen AAW (age, 42±10.4 years; body mass index [BMI], 39±5.8 kg/m(2)) were studied on 2 occasions, 4 weeks apart, under fasting conditions (study 1 and study 2). In protocol 2, we used the most repeatable measurement from protocol 1 to assess changes in endothelial function after an HFM in 17 AAW (agen 42±11.1 years; BMIn 38±5.6 kg/m(2)). We found that FMDpeak was the most repeatable measurement (N=16; study 1, 5.31±3.12% and study 2, 5.80±2.91%; r=0.94). After an HFM, the baseline brachial artery diameter significantly increased at 2 hours (0.10 mm; 95% confidence interval [CI], 0.01-0.18; P=0.03) and at 4 hours (0.17 mm; 95% CI, 0.09-0.25; P<0.001). At 2 hours, the FMDpeak decreased compared with pre-HFM (-1.76; 95% CI, -3.55-0.02; P≤0.05).
  
  
  CONCLUSIONS
  The individual's maximum peak dilation after hyperemia is the most consistent measure to assess the effect of an HFM on endothelial function. Endothelial dysfunction occurred at 2 hours after an HFM in AAW.
  
  
  BACKGROUND
  URL: https://clinicaltrials.gov/ Unique identifiers: NCT01334554 and NCT02126735.
authors.affiliation: Department of Internal Medicine, William Beaumont Hospital Internal Medicine, Royal Oak, MI (A.M.).
authors.forename: Alejandro
authors.initials: A
authors.lastname: Marinos
authors.affiliation: Department of Medicine, Division of Clinical Pharmacology and the Autonomic Dysfunction Center, Vanderbilt University School of Medicine, Nashville, TN (J.E.C., C.E.R., A.G., M.S., I.B., C.A.S.).
authors.forename: Jorge E
authors.initials: JE
authors.lastname: Celedonio
authors.affiliation: Department of Medicine, Division of Clinical Pharmacology and the Autonomic Dysfunction Center, Vanderbilt University School of Medicine, Nashville, TN (J.E.C., C.E.R., A.G., M.S., I.B., C.A.S.).
authors.forename: Claudia E
authors.initials: CE
authors.lastname: Ramirez
authors.affiliation: Clinical Research Center, Vanderbilt University School of Medicine, Nashville, TN (J.A.G.).
authors.forename: JoAnn
authors.initials: J
authors.lastname: Gottlieb
authors.affiliation: Department of Medicine, Division of Clinical Pharmacology and the Autonomic Dysfunction Center, Vanderbilt University School of Medicine, Nashville, TN (J.E.C., C.E.R., A.G., M.S., I.B., C.A.S.).
authors.forename: Alfredo
authors.initials: A
authors.lastname: Gamboa
authors.affiliation: Department of Biostatistics, Vanderbilt University School of Medicine, Nashville, TN (N.H., C.Y.).
authors.forename: Nian
authors.initials: N
authors.lastname: Hui
authors.affiliation: Department of Biostatistics, Vanderbilt University School of Medicine, Nashville, TN (N.H., C.Y.).
authors.forename: Chang
authors.initials: C
authors.lastname: Yu
authors.affiliation: Department of Medicine, Division of Clinical Pharmacology and the Autonomic Dysfunction Center, Vanderbilt University School of Medicine, Nashville, TN (J.E.C., C.E.R., A.G., M.S., I.B., C.A.S.).
authors.forename: C Michael
authors.initials: CM
authors.lastname: Stein
authors.affiliation: Department of Medicine, Division of Clinical Pharmacology and the Autonomic Dysfunction Center, Vanderbilt University School of Medicine, Nashville, TN (J.E.C., C.E.R., A.G., M.S., I.B., C.A.S.).
authors.forename: Italo
authors.initials: I
authors.lastname: Biaggioni
authors.affiliation: Department of Medicine, Division of Clinical Pharmacology and the Autonomic Dysfunction Center, Vanderbilt University School of Medicine, Nashville, TN (J.E.C., C.E.R., A.G., M.S., I.B., C.A.S.).
authors.forename: Cyndya A
authors.initials: CA
authors.lastname: Shibao
mesh_terms: D000328:Adult; D001741:Black or African American; D015992:Body Mass Index; D001916:Brachial Artery / Q000000981:diagnostic imaging / Q000503:physiopathology*; D059305:Diet, High-Fat / Q000009:adverse effects*; D004730:Endothelium, Vascular / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005260:Female; D006801:Humans; D006940:Hyperemia / Q000503:physiopathology; D008297:Male; D062407:Meals; D008875:Middle Aged; D009765:Obesity / Q000000981:diagnostic imaging / Q000208:ethnology / Q000503:physiopathology*; D011237:Predictive Value of Tests; D012039:Regional Blood Flow; D015203:Reproducibility of Results; D013997:Time Factors; D014463:Ultrasonography; D014664:Vasodilation
keywords: African American; endothelial dysfunction; high fat diet; obesity