Master of Science (MS)
Human aging is associated with deterioration in physical functional ability. The causes are complex and multifactorial, but are presumed to include the presence and extent of cardiovascular disease. Purpose: To examine the associations between brachial artery (BA) dimensions, flow-mediated dilation (BAFMD) and physical function in 28 older adults (age: 84.6±10.9, range 66 to 98 yrs). Methods: High-resolution ultrasonography was used to measure BA diameters at rest and following 5min of forearm occlusion. Physical function was assessed using the Continuous Scale-Physical Function Performance (CS-PFP) test. Results: Pearson correlation revealed that BAFMD (r =-.39), and all physical function parameters of the CS-PFP declined with age at an alpha of p= .04 and p< .01, respectively (UBS, r= -.69; UBF, r= -.78; LBS, r= -.77; BALCOR, r= -.74; END, r= -.81; PFP total score, r= -.79). Six-minute walk scores (a component of the CS-PFP) also declined with age (r= -.72, p <0.01). Mean BA resting diameter and BAFMD were 4.31±0.77mm and 1.89±1.99%, respectively. Resting diameter was inversely associated with BAFMD (r= -.45, p= .02). Partial correlation (controlling for BMI) was used to account for the influence of participant size on vascular and physical function measures. The results indicated an association between BAFMD and several CS-PFP sub-scales with an alpha of p< .05 (END, r= .40; UBF, r= .39; LBS, r= .39; BALCOR, r= .38). CS-PFP total score (r= .38) and UBS (r= .28) were associated with BAFMD at alpha of p= .06 and p= .18, respectively. Notedly, the difference between resting and peak diameters, as a group, was not significant for the study sample. Two participants in the study sample had BAFMD> 5%, thus the sample was biased towards “non-responders.” Conclusion: These results appear to confirm predicted trends for physical function decline and reduced vasoreactivity in older adults. Uniquely, this study is the first to suggest a link between BA reactivity and age-appropriate measures of physical functional status. Therefore, BAFMD could potentially provide information regarding the impact of CVD and vasoreactivity on the functional characteristics of the population. Funded by the Louisiana Board of Regents Millennium Trust Health Education Fund. [I HEF (2001-06)-02]
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King, Christina M., "Brachial artery dimensions, flow-mediated reactivity and physical function in older adults" (2004). LSU Master's Theses. 3374.