@article {665, title = {Brachial flow-mediated vasodilator responses in population-based research: methods, reproducibility and effects of age, gender and baseline diameter.}, journal = {J Cardiovasc Risk}, volume = {8}, year = {2001}, month = {2001 Oct}, pages = {319-28}, abstract = {

BACKGROUND: Brachial artery ultrasound has been proposed as an inexpensive, accurate way to assess cardiovascular risk in populations. However, analysis and interpretation of these data are not uniform.

METHODS: We analysed the relationship between relative and absolute changes in brachial artery diameter in response to flow-mediated dilation and age, gender and baseline diameter among 4,040 ultrasound examinations from subjects aged 14 to 98 years.

RESULTS: Reproducibility studies demonstrated intra- and interreader and intrasubject correlations from 0.67 to 0.84 for repeated measures of per cent change in diameter. Per cent change in diameter after flow stimulus was 3.58 +/- 0.10\% (mean +/- standard deviation). Corresponding values for baseline diameter and absolute change in diameter were 4.43 +/- 0.87 mm and 0.15 +/- 0.01 mm, respectively. Baseline diameter and its variance were inversely related to per cent change in diameter (P< 0.001). In contrast, absolute change in diameter was more uniform throughout the range of baseline diameters. Baseline diameter was directly related, and per cent change in diameter inversely related, to age (P < 0.001 for all three measures). Time to maximum vasodilator response increased with age (P < 0.001). Women (n=2,315) had significantly larger per cent change in diameter than men (n=1,725) (P < 0.001). However, after adjustment for age and baseline diameter, per cent and absolute change were 5\% smaller in women than men (P < 0.05 for both). In multivariate analysis, age was overwhelmingly the most important determinant of absolute change in diameter (P < 0.001).

CONCLUSIONS: Automated analysis of brachial flow-mediated vasodilator responses is both feasible and reproducible in large-scale clinical and population-based research.

}, keywords = {Adolescent, Adult, Age Factors, Aged, Aged, 80 and over, Blood Circulation, Brachial Artery, Female, Humans, Male, Middle Aged, Observer Variation, Population Surveillance, Reproducibility of Results, Sex Factors, Vasodilation, Vasodilator Agents}, issn = {1350-6277}, doi = {10.1177/174182670100800512}, author = {Herrington, D M and Fan, L and Drum, M and Riley, W A and Pusser, B E and Crouse, J R and Burke, G L and McBurnie, M A and Morgan, T M and Espeland, M A} }