[Detection of structural changes of large arteries by characteristics of peripheral pulse wave: comparison with high...

To compare high-resolution ultrasound of major arteries and the method of vascular stiffness evaluation by digital volume pulse photoplethysmography after sublingual nitroglycerin in diagnosis of structural vascular changes.

The comparison of the two methods was made in 110 volunteers (mean age 31.9 +/- 11.5 years). The study protocol included measurement of blood pressure (BP), blood lipids and glucose, evaluation of IMT of the carotid arteries by ultrasonography, baseline stiffness index (SIbl) and after sublingual nitroglycerin (SIng) by photoplethysmography. Reproducibility of photoplethysmography was evaluated in 20 volunteers (mean age 20.3 +/- 1.4 years) with repeated measurement after 1 week. The results were tested in 40 volunteers of different age groups.

There were significant correlations of IMT, SIbl and SIng with risk factors and close interrelations of these parameters. SIng better explained variability of IMT compared to SIbl (r = 0.79, R2 = 0.62, p < 0.001 versus r = 0.67, R2 = 0.45, p < 0.001, respectively). Relations of IMT with risk factors were lost after correction for SIng. Reproducibility of SIng was higher than SIbl (+/- 5.1% versus +/- 10.9%, respectively) and than those for IMT found in the literature. Mean IMT values for random sample evaluated by ultrasonography and calculated by estimated equation of linear regression for SIng and IMT did not differ significantly (0.576 +/- 0.087 mm versus 0.570 +/- 0.074 mm, p = 0.44; r = 0.71, p < 0.001, mean difference 0.007 +/- 0.051 mm).

The method of vascular stiffness measurement is comparable with ultrasonography in terms of vessel structure evaluation and possesses higher reproducibility. The test with nitroglycerin substantially increases its diagnostic potential and reproducibility.