Browsing by Subject "Vascular Function"

Now showing 1 - 2 of 2
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    Comparison of baseline brachial artery measurements and effect on peak flow-mediated dilation
    (2013-08) Ostrem, Joseph Dwayne
    The aim of this study was to examine the effect of pre-occlusion, occlusion, and post-occlusion baseline brachial artery measurements on the calculation of peak flow mediation dilation (FMD). Ultrasound imaging of the brachial artery following reactive hyperemia was conducted in 418 children and 533 adults. Baseline brachial artery measures were a 10-second average before (pre-occlusion), during (occlusion), and after (post-occlusion) hyperemia. Peak FMD was defined as the change from baseline to the peak brachial artery diameter following reactive hyperemia. Pre-occlusion, occlusion, and post-occlusion baseline measures of brachial artery diameter were not significantly different in children (3.15±0.51, 3.14±0.50 vs. 3.11±0.50 mm, P=0.179) or adults (3.81±0.72, 3.81±0.73 vs. 3.79±0.73 mm, P=0.201). Peak FMD values were not significantly different when calculated from pre-occlusion, occlusion, or post-occlusion baselines in children (6.77±5.78, 6.93±4.03 vs. 7.85±3.62%, P=0.208) or adults (6.06±5.53, 6.12±3.94 vs. 6.62±3.70%, P=0.266). We found no differences in FMD regardless of the baseline brachial artery diameter used in children or adults. Therefore, comparison of data from studies utilizing different measures of baseline brachial diameter can be conducted without correction of data.
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    Endothelium-independent dilation in children and adolescents
    (2011-08) Marlatt, Kara Lynn
    Peak brachial artery dilation post-nitroglycerin (NTG) administration occurs between 3 and 5-min in adults. The purpose of this study was to identify the time to peak dilation response to sublingual NTG (0.3 mg) in youth. Endothelium-independent dilation (EID) was measured in 198 healthy (113 males, 85 females) youth (6-18 yrs) via ultrasound imaging of the brachial artery following NTG administration up to 5-min. Time to peak EID was 4-min, 28-sec, following NTG administration. There was a significant (p<0.001) difference post-NTG at the 3 vs. 4-min, 4 vs. 5-min, and 3 vs. 5-min time points. Peak EID (males: 24.8 + 0.5 vs. females: 25.3 + 0.6 %, p=0.6) was not significantly different between genders after adjusting for baseline brachial diameter. Endothelium-independent dilation was measured up to 8-min in a small sub-group of 20 youth (12 males, 8 females), resulting in a time to peak dilation of 4-min, 24-sec, and an average change in peak dilation of 23.8 + 1.2 %. No significant difference existed beyond the 4-min time point within the small sub-group. In conclusion, peak response to NTG administration occurred between 4 and 5-min. The results demonstrate the importance of measuring EID up to 5-min post-nitroglycerin administration in youth.