Lyudmila Vladimirova-Kitova

Intima-Media Thickness and Flow-Mediated Vasodilation in Asymptomatic Subjects with Newly Detected Severe Hypercholesterolemia

Background: The aim was to establish the predictors of early functional and structural vascular alterations (using intima‐media thickness (IMT)) and flow‐mediated vasodilation (%FMD) as well as to investigate the interrelationship between IMT and %FMD in asymptomatic, never‐treated, severe hypercholesterolemia (HH). Methods: One hundred and twenty patients with asymptomatic, severe, untreated HH and 100 controls were included. ELISA was used for asymmetric dimethylarginine (ADMA) and cellular adhesion molecules, and fluid chromatography for total homocysteine (tHcy). Hewlett Packard SONOS 5500 with a 7.5 MHz transducer and MedicaSoft IMT software were used for evaluation of %FMD and IMT of common carotid artery (CCA). Results: Patients and controls differ with respect to all tested biomarkers (P < 0.05), except for P‐selectin and E‐selectin (P < 0.05). %FMD was lower in patients (P < 0.001). The IMT of the CCA was higher in patients (P < 0.001). Inverse correlations were found between %FMD and IMT mean and age, ADMA, Apo‐B, Apo‐B/Apo‐A1, and tHcy. ADMA was established as the most important factor related to %FMD. Age and Apo‐B were established as the most important factors related to IMT mean. An inverse correlation was established between %FMD and IMT mean (rxy= 0.546; P < 0.001)). If cases with IMT mean ≥1 were excluded, the correlation weakened. In patients with IMT mean ≥1 mm, the correlation did not change. Conclusion: In conclusion, asymptomatic, untreated patients with severe hypercholesterolemia are at high risk of having increased IMT of the CCA, especially if there is endothelial dysfunction, verified by %FMD of the brachial artery.

The effect of simvastatin on asymmetric dimethylarginine and flow-mediated vasodilation after optimizing the LDL level: a randomized, placebo-controlled study.

Research of statin influence on asymmetric dimethylarginine (ADMA) and flow-mediated vasodilatation (FMD) reveals controversial results. The aim of this study was to investigate the effects of moderate (40mg) and high (80mg) simvastatin doses on the levels of ADMA, total homocysteine (tHcy) and %FMD in patients with newly diagnosed severe hypercholesterolemia, after optimizing the LDL level. The study included 650 patients with severe hypercholesterolemia (total cholesterol≥7.5mmol/l; LDL≥4.9mmol/l). The treatment groups were administered 80mg simvastatin over a period of one month. The results indicated a reduction in ADMA and tHcy levels and an increase in %FMD in the treatment groups, compared with the control groups (receiving placebo or 40mg simvastatin). There was a statistically significant correlation between the %FMD changes and the baseline levels of Apo-B, ADMA and tHcy, as well as between the %ADMA changes and %LDL, % apolipoprotein-B and %tHcy-changes in patients on 80mg Simvastatin. A statistical linear regression analysis (in the treatment group) indicated that the baseline ADMA level is the most important statistically significant predictor related to %FMD-changes. A linear regression analysis additionally documented that % apolipoprotein-B-changes is a predictor of %ADMA-changes. In conclusion, in cases with optimized LDL-target levels (patients on 80mg Simvastatin), the baseline level of ADMA appears to be a major modulator of %FMD-changes.

Serum levels of sICAM-1, sVCAM-1, sE-selectin, sP-selection in healthy Bulgarian people

Abstract Background: Endothelial dysfunction is increasingly recognized as an important early feature of vascular disease. As the damage to endothelium is a key underlying factor in the development and progression of atherosclerotic processes, markers of endothelial abnormalities have been sought. Increased expression of cell adhesion molecules (CA Ms) on the vascular endothelium has been postulated to play a significant role in atherogenesis. Both in vitro and in vivo studies have suggested that different risk factors of atherosclerosis may increase expression of CA Ms. The elevated level of soluble forms of CA Ms in circulation is associated with a higher risk to future cardiovascular events in subjects predisposed to atherosclerosis. Objective: To determine the reference range for serum concentration of soluble cell adhesion molecules - sICA M-1, sVCA M-1, sE-selectin, sP-selectin. Materia l and methods: We studied 110 healthy people of Bulgarian nationality aged 18-65. The selection criteria for the reference group were made in accordance with the requirements of the International Federation of Clinical Chemistry (IFCC ). Serum concentrations of CA Ms were analysed by means of EL ISA assay. Results: The results are presented as central 95% interval and 0.90 confidence interval of the reference range. Reference ranges were determined for sICA M-1 (128.9 - 347.48 ng/ml), sVCA M-1 (170.42 - 478.36 ng/ml), sE-selectin (9.15 - 65.19 ng/ml) and sP-selectin (101.86 - 209.7 ng/ml). As we found no sex-related differences in the CA Ms concentrations (p > 0.05) there needed to be no separate reference intervals for men and women. The single-factor dispersion analysis we used in analysing the effect of age found no agerelated dependence (p > 0.05, F = 1.038) for the serum CA M concentrations in the 18-65 age range, which means that it is not necessary to establish reference intervals for smaller age ranges in this age group. Conclusion: The reference ranges for sICA M-1, sVCA M-1, sE-selectin, sP-selectin computed in accordance with the results distribution can be used as baseline criteria in clinical laboratory studies. Резюме Повреждение эндотелия сосудов является клю- чевым фактором в развитии и прогрессии атеро- склеротического процесса. Это определяет и поиск подходящих и достоверных маркеров для эндотелиальной дисфункции. Ряд эксперименталь- ных и клинических исследований доказывает, что повышенная экспрессия клеточных адгезионных молекул (КАМ) играет значимую роль в атерогенезе. Увеличенные уровни циркулирующих адгезионных молекул связывают с повышенным риском сердечно- сосудистых осложнений среди лиц с факторами риска атеросклероза. Цель: Исследование ставит себе целью определить референтные границы КАМ: - sICAM-1, sVCAM-1, sE-selectin и sP-selectin. Материал и методы: В целях определения границ референтной области КАМ в сыворотке и изучения влияния факторов “пол” и “возраст” обследовано 110 здоровых лиц болгарской национальности в возрасте от 18 до 65 лет. Критерии подбора референтной группы соображены с общепринятыми рекомендациями IFCC. Сывороточная концентрация КАМ определена иммунометрически с помощью ELISA-анализа. Результаты: Референтные границы, выраженные как центральный 95-процентный интервал полученных стоимостей, следующие: 1128.9 - 347.48 ng/ml для sICAM-1 ; 170.42 - 478.36 ng/ml для sVCAM-1 ng/ml; для sE-selectin - 9.15 - 65.19 ng/ml; для sP-selectin - 101.86 - 209.7 ng/ml. Пол не оказывает влияние на концентрацию КАМ (p > 0.05), вот почему нет необходимости в использовании отдельных референтных границ для мужчин и женщин. Прослеживание влияния возраста посредством однофакторного дисперсионного анализа не уста- навливает возрастную зависимость: p > 0.05, (F = 1.038) для сывороточных концентраций КАМ при обследованной референтной группе в возрасте от 18 до 65 лет, что не требует формирования референтных границ для меньших возрастных ин- тервалов. Заключение: Референтные стоимости sICAM-1, sVCAM-1, sE-selectin и sP- selectin в сыворотке, вычисленные сообразно с видом распределения ре- зультатов, могут служить исходными критериями при проведении клинико-лабораторных исследований и позволяют их пользование с клинической целью.

Increased intima-media thickness in carriers of the ldl-receptor defective gene versus noncarriers with newly detected asymptomatic severe hypercholesterolemia.

Background: The data on the examination of early vascular alterations in carriers of molecular defects of the low‐density lipoprotein‐receptor (LDL‐R) in comparison to noncarriers with severe hypercholesterolemia are controversial. Aims: To examine the difference between patients with severe hypercholesterolemia, who are carriers and noncarriers of LDL‐R defective gene, with respect to their functional (flow‐mediated vasodilation) and structural (intima‐media thickness of carotid artery) characteristics of arterial wall. A total of 250 hypercholesterolemic patients were enrolled. Biochemistry parameters were examined by routine methods. The molecular biological analysis included‐R3500Q‐mutation in the Apolipoprotein‐B (Apo‐B) gene, LDL‐R gene mutation and polymorphism (and the promoter region), as large rearrangements. Determination of flow‐mediated vasodilation and intima‐media thickness of common carotid artery was performed with Hewlett Packard Sonos 5500, using automated computer software MedicaSoft. IMT.lab. Results: There was no significant difference between the groups with respect to total cholesterol, LDL, HDL, Apo‐B, Apolipoprotein A1 (Apo‐A1), asymmetric dimethylarginine (ADMA), homocysteine, and cellular adhesion molecules. The Apo‐B/Apo A1 index differed significantly (t = 11.23, P < 0.001) between the two groups and this difference was found even after adjustment for age and gender. There was no significant difference with respect to the endothelial dependent and independent vasodilatation between the examined groups (P > 0.05). We were founded a significantly higher carotid IMT in the carriers versus noncarriers. This significant difference was confirmed after adjustment for age and gender. Statistically significant correlations we were founded between IMT mean and age (log) (rxy= 0.45; P < 0.01), cholesterol × years score (log) (rxy= 0.53; P < 0.01), Apo–B/A1 (log) (rxy= 0.66; P < 0.001) in the group of the carriers. Backward selection process selected Apo‐B/A1 as the most important statistically significant factor related to IMT mean of common carotid artery (F = 105.22; P = 0.001; R2= 0.72). Conclusion: Our data demonstrate that carriers of the LDL‐R defective gene have a higher carotid IMT and Apo B/Apo A1 index than noncarriers, whereas no difference between the groups was found with respect to the level of lipid parameters, ADMA, total homocysteine, cell adhesion molecules and %FMD. Apo‐B/A1 is a predictor of IMT mean in the group of the carriers of the LDL‐receptor gene. (Echocardiography 2011;28:223‐234)

Effect of moderate and high dose simvastatin on adhesion molecules in severe hypercholesterolemia after targeting the LDL-cholesterol – a randomised, placebo-controlled study

Abstract Introduction: The effect of statins on the levels of cell adhesion molecules (CAM) is discussed in the literature as one of the pleiotropic effects of the drugs. This effect is one of the ways that could be used to control the initial stage of atherogenesis. The research in this field is inadequate and controversial. Prevention guidelines recommend that target levels of LDL cholesterol in high-risk patients should be less than 2.6 mmol/l. If the primary target is LDL -cholesterol, it is doubtful if patients can have any significant changes in the levels of the cell adhesion molecules (CAM). Aim: Study the effect of simvastatin administered in a moderate dose of 40 mg and in a high dose of 80 mg on endothelium activation in the context of the plasma levels of soluble cellular adhesion molecules (sICAM-1, sVCAM-1, sE-selectin, sP-selectin) in recently diagnosed untreated severe hypercholesterolemia after reaching target levels for the LDL-cholesterol below 2.6 mmol/l. Patients and methods: One hundred patients (aged > 16 years) were included in the study. Hypercholesterolemia was defined as fasting total serum cholesterol level greater than 7.5 mmol/l and LDL -cholesterol > 4.9 mmol/l. The study was carried out in three phases, the main goal being titration of simvastatin dose from 40 to 80 mg with the purpose of achieving the target LDL level of < 2.6 mmol/l in a randomised placebo-controlled study. Results: There was a statistically significant reduction of sVCAM-1 following the 80-mg simvastatin therapy for one month after reaching target levels of LDL-cholesterol < 2.6 mmol/l in hypercholesterolemic patients in comparison with the moderate dose (40 mg) of simvastatin for one month (p < 0.001). The results of the study demonstrated that simvastatin in a dose of 80 mg exerted an effect on the levels of some CAM, and particularly on VCA M-1 in contrast to the same drug used in a dose of 40 mg . Conclusion: As different statins most likely have a distinctly specific effect on different adhesion molecules, this study seeks to establish a suitable panel of such adhesion molecules that may be used in monitoring statin therapy. Резюме Введение В литературе обсуждается влияние статинов на уровни растворимых клеточных адгезионных молекул (КАМ). Таким образом де- лается опыт контролировать начальные этапы атерогенеза. Исследования в этом направлении недостаточны и противоречивы. Имеющиеся руко- водства профилактики рекомендуют таргетные уровни LDL-холестерола при высоко рисковом кон- тингенте < 2.6 mmol/l. В случае, что основной целью является LDL-холестерол, то нет ясности по проблеме “каков эффект на уровне САМ”. Цель: Изучение эффекта умеренной (40 mg) и высокой (80 mg) доз Симвастина на эндотелиальное активирование в контексте плазменных уровней растворимых клеточных адгезионных молекул (sICAM- 1, sVCAM-1, E-селектин, P-селектин) при новообнаруженной тяжкой гиперхолестеролемии после достижения таргетных уровней LDL-cholesteroh < 2.6 mmol/l. Пациенты и методы: В исследование включено 100 пациентов в возрасте свыше 16 лет. Гипер- холестеролемия определена как уровень общего холестерола > 7.5 mmol/I и LDL-холестерола > 4.9 mmol/l. Исследование проведено в трех этапах, при чем основной целью является титрирование Симвастин-а в дозах от 40 до 80 мг с целью достижения уровня LDL < 2.6 mmol/l в условиях рандомизации и плацебо-контролированного иссле- дования. Результаты: Установлено статистически значимое уменьшение sVCAM-1 на фоне 80 мг Симвастатин-а за месяц после достижения таргетных уровней LDL- холестерола < 2.6 mmol/l по сравнению с умеренной дозой (40 мг) Симвастин-а за месяц (р < 0.001). Данные этого исследования доказывают, что доза 80 мг оказывает влияние на уровни некоторых САМ и более конкретно на VCAM-1, что контрастирует с умеренной дозой - 40 мг Симвастин-а. Выводы: Статинины созданы различными и вполне логично, что они оказывают специфический эффект на различные САМ, а также они являются необходимыми доказательствами для создания подходящей панели САМ, которые могут служить контролем статинового лечения.

Non-invasive vessel examinations in carriers of LDL-receptor defective gene versus non-carriers with newly detected asymptomatic severe hypercholesterolemia.

Non-Invasive Vessel Examinations in Carriers of LDL-Receptor Defective Gene Versus Non-Carriers with Newly Detected Asymptomatic Severe Hypercholesterolemia The results of the research of early vascular alterations in LDL-R carriers in comparison with those in non-carriers with severe hypercholesterolemia are controversial. Aim: To investigate the difference between severe hypercholesterolemia patients that carry LDL-R defective gene and those that do not have it, in their functional (flow-mediated vasodilation) and structural (intima-media thickness of carotid artery and ankle-brachial index) characteristics of arterial wall. Pateints and methods: The study included 120 hypercholesterolemic patients. Biochemistry parameters were studied by routine methods. The flow-mediated vasodilation (%FMD), ankle-brachial index (ABI) and intima-media thickness (IMT) of common carotid artery were determined using Hewlett Packard Sonos 5 500; MedicaSoft. IMT.lab was the software programme used in the study. Results: There was no significant difference between the groups with respect to total cholesterol, LDL, HDL, Apo-B, Apo-A1, cellular adhesion molecules (sICAM-1, sVCAM-1, sP- and sE-selectine). The Apo-B/Apo A1 index differed significantly (t = 11.23, p < 0.001) between the two groups; there was difference even after adjustment for age. There was no significant difference in the endothelial dependent and independent vasodilatation between the examined groups (p > 0.05). We found a significantly greater carotid IMT and lower ABI in the carriers than the respective parameters in the non-carriers. This significant difference was confirmed after adjustment for age. Conclusion: Our data show that LDL-R carriers have a higher carotid IMT and lower ABI than non-carriers, whereas no difference between the groups was found with respect to the level of lipid parameters and %FMD. Неинвазивные сосудистые ис-следования относительно нали-чия дефектов молекул LDL-pe-цепторного гена при новооб-наруженной выраженной асимп-томатической гиперхолестеро-лемии Данные исследований ранних сосудистых изменений носителей молекулярных дефектов LDL-рецепторного гена относительно неносителей при тяжелой форме гиперхолестеролемии противоречивы. Цель: Работа ставит себе целью исследовать разницу между пациентами с тяжелой формой гиперхолестеролемии, являющимися носителями или неносителями LDL-рецепторного дефектного гена, в контексте их функциональных (поток-индуцированная вазидилатация) и структурных (интима-медия комплекс каротидной артерии и лодыжка-рука индекс) характеристик артериальной стенки. Обследовано 120 пациентов с асимптоматической гиперхолестеролемией. Биохимические параметры определены с помощью рутинных методик. Опре-деление поток-индуцированной вазодилатации, лодыжка-рука индекса и интима-медия комплекса каротидной артерии осуществлено эхокардиографом Hewlett Packard sonos 5 500 с применением авто-матической компьютерной программы Meclica Soft ШТ. Lab. Результаты: Не установлена сигнификантная разница между группами по отношению к общему холестеролу LDL-холестеролу, HDL-холестеролу, Аполипопротеину В, Аполипопротеину А1, клеточным адгезионным молекулам (slCAM-1, sVCAM-1, sP and sE-selectine). Индекс Apo-B/Apo Al различается сигнификантно между обеими группами (t = 11.23, р < 0.001) и эта разница подтверждается и после стандартизирования возраста. Не устанавливается разница в контексте эндотелий-зависимой и эндотелий-независимой вазодилатации среди об-следованных групп (р > 0.05). Устанавливается сигнификантно больший размер интима-медия комплекса и более низкий лодыжка-рука индекса среди носителей относительно неносителей. Эта разница подтверждается после стандартизирования возраста. Заключение: Полученные данные показывают, что носители LDL-R дефектного гена имеют больший размер интима-медия комплекса каротидной артерии и более низкий лодыжка-рука индекса, чем неносители, при чем не устанавливается разница между группами по отношению к уровням липидных параметров и к эндотелий-зависимой вазодилатации.