Total plasma homocysteine in Bulgarian population measured by high-performance liquid chromatography with fluorescence detection--comparison with fluorescence polarization immunoassay.

Over the last decade, evidence has accumulated that elevated total homocysteine (tHcy) is an independent risk factor for vascular disease. Due to the variety of Hcy determinants (age, gender, ethnicity and lifestyle), it is now recommended that the distribution of plasma Hcy concentrations should be established for different populations. Therefore the objective of our study was to evaluate a modified HPLC with fluorescence detection procedure for reliable quantification of tHcy and to demonstrate its successful application to determine the distribution of tHcy levels in healthy Bulgarians. The presented method showed good analytical performance (intra- and interassay CVs were <3.9% and <6.7%, respectively; inaccuracy was <6.5%, and analytical recovery 95%-98%, the detection limit was 0.3 micromol/l) and no drug interference was registered. Comparison between HPLC-FD and FPIA using Passing-Bablok regression analysis (r=0.9906) showed good agreement. We describe the distribution of plasma tHcy in a group of 162 healthy Bulgarian adults and examined its relation with age and gender. Our results indicate that higher Hcy concentrations were associated with male sex and increasing age. The higher plasma Hcy observed in our population compared to the rest of Europe corresponds to the high prevalence and mortality of cardiovascular disease in Bulgaria.