Christopher D Black, Bakari Vickerson, Kevin K McCully
{"title":"Noninvasive assessment of vascular function in the posterior tibial artery of healthy humans.","authors":"Christopher D Black, Bakari Vickerson, Kevin K McCully","doi":"10.1186/1476-5918-2-1","DOIUrl":"https://doi.org/10.1186/1476-5918-2-1","url":null,"abstract":"<p><p>Flow-mediated dilation (FMD) measures the ability of an artery to relax in response to increases in blood velocity. FMD, primarily of the brachial artery, has been used as a noninvasive method of assessing vascular health. The purpose of this study was to assess FMD in the lower legs of humans. Six healthy subjects (27 PlusMinus; 6 yrs) were tested. Doppler ultrasound images of the posterior tibial artery were taken before, during, and after 5 minutes of proximal cuff occlusion. FMD was measured as the percent increase in diameter after cuff release. Vascular tone was calculated using the resting diameter as a percentage of the vessel's vasoactive range. Minimum diameter occurred during ischemia and maximal diameter occurred following reactive hyperemia with local heating. The lower leg was heated with 10 minutes of immersion in 44 degrees C water. Mean diameters at rest, cuff, and during release were 0.267 PlusMinus; 0.062, 0.162 PlusMinus; 0.036, 0.302 PlusMinus; 0.058 cm, respectively. FMD was 13.5 PlusMinus; 6.6 % and vascular tone was 29 PlusMinus; 16.3%. We also found that retesting on a second day produced mean diameter values within 8% of the first day. Larger resting diameter (decreased tone) correlated with decreased FMD (r2 = 0.73). These results suggest that FMD and vascular tone can be measured in the posterior tibial artery. This is a potentially powerful tool to non-invasively measure vascular health in the lower legs of people at risk for vascular disease.</p>","PeriodicalId":84611,"journal":{"name":"Dynamic medicine : DM","volume":"2 1","pages":"1"},"PeriodicalIF":0.0,"publicationDate":"2003-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/1476-5918-2-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"22282562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jennifer L Olive, Allison E DeVan, Kevin K McCully
{"title":"The effects of aging and activity on muscle blood flow.","authors":"Jennifer L Olive, Allison E DeVan, Kevin K McCully","doi":"10.1186/1476-5918-1-2","DOIUrl":"https://doi.org/10.1186/1476-5918-1-2","url":null,"abstract":"<p><strong>Background: </strong>Our purpose was to determine if aging had an influence on muscle blood flow independent of habitual physical activity levels.</p><p><strong>Methods: </strong>Blood flow was measured in the femoral artery by Doppler ultrasound after cuff occlusion of 10 minutes. Active and inactive older subjects (73 +/- 7 years) were compared to active and inactive young subjects (26 +/- 6 years).</p><p><strong>Results: </strong>Peak blood flow capacity when normalized to lean muscle mass was related to activity level (p < 0.001), but not to age. Specifically, the young active group had higher peak blood flows than the young inactive (p = 0.031) or older inactive (p = 0.005) groups. Resting blood flow and conductance were not significantly different between groups. Mean arterial pressure was significantly higher in the older compared to young group (p = 0.002). Conductance was related to both activity (p = 0.002) and age (p = 0.003). A prolonged time for blood flow to recover was found in the older compared to the young group (p = 0.038) independent of activity status.</p><p><strong>Conclusions: </strong>The prolonged recovery time in the older subjects may suggest a reduced vascular reactivity associated with increased cardiovascular disease risk. Peak blood flow capacity is maintained in older subjects by physical activity. In summary, maximal flow capacity and prolonged recovery of blood flow are influenced by different mechanisms in young and older active and inactive subjects.</p>","PeriodicalId":84611,"journal":{"name":"Dynamic medicine : DM","volume":"1 ","pages":"2"},"PeriodicalIF":0.0,"publicationDate":"2002-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/1476-5918-1-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"22262896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Dynamic Medicine: the start of a new online journal.","authors":"Takafumi Hamaoka, Kevin K McCully","doi":"10.1186/1476-5918-1-1","DOIUrl":"https://doi.org/10.1186/1476-5918-1-1","url":null,"abstract":"","PeriodicalId":84611,"journal":{"name":"Dynamic medicine : DM","volume":"1 1","pages":"1"},"PeriodicalIF":0.0,"publicationDate":"2002-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/1476-5918-1-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"22204792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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