Biomedical subjects

Christos M Papamichael

Publications and source records attributed to Christos M Papamichael.

At least 19 recordsLinked to original sources

PubMed2007

Central blood pressures: do we need them in the management of cardiovascular disease? Is it a feasible therapeutic target?

It is well established that in young and healthy individuals central (aortic or carotid) systolic and pulse pressures are different from peripheral (brachial) corresponding pressures as a consequence of progressive changes in arterial stiffness and pressure wave reflections along the arterial tree. There is evidence indicating that in interventions with pharmaceutical and non-pharmaceutical agents, central pressures are subjected to greater changes than peripheral pressures, and they are more closely related to the pathophysiology of end-organ damage or cardiovascular risk. Therefore central blood pressures may be of higher clinical importance than peripheral pressures. The present review aims to provide an insight into the (patho)physiology of central blood pressures, to present the most accurate techniques for their estimation, and to discuss the available experimental and epidemiological data that support the emerging need for the evaluation of central blood pressures in clinical practice.

Aorta↗

PubMed2006

The relative impact of different measures of adiposity on markers of early atherosclerosis.

BACKGROUND: Although there are several methods available to assess adiposity, there is still controversy on the relative clinical utility of each of these methods. This study examines the relative impact of different measures of adiposity on markers of early atherosclerosis. In particular weight changes over time have been poorly assessed in this setting. METHODS: Eighty-six healthy individuals (31 men, age 36.5+/-8.9 years) with a wide range of body-mass index (28.7+/-7.0, 18.9-57.9 kg/m2) without hypertension, diabetes or smoking were examined. In addition to waist circumference and waist-to-hip ratio self-reported weight change since adolescence was also calculated. Ultrasonography was used to measure abdominal fat layers and their ratio. Flow-mediated dilatation of the brachial artery, serum levels of intercellular adhesion molecule (sICAM-1) and mean intima-media thickness of the carotid artery were measured as markers of early atherosclerosis. RESULTS: Stepwise multivariate regression analysis showed waist circumference and waist-to-hip ratio as the only independent predictor of flow-mediated dilatation. Waist circumference and weight change but not current body-mass index were independent predictors of intima-media thickness. These correlations were not influenced by ultrasonographically measured fat layers, C-reactive protein and basal insulin resistance. Body-mass index and weight gain were associated with sICAM-1 but not independently of basal insulin resistance and C-reactive protein. CONCLUSIONS: Waist circumference and weight gain were the strongest predictors of early atherosclerosis in a population of apparently healthy adults. The ultrasonographically measured fat layers did not provide additional information in this population.

Abdominal Fat↗

PubMed2006

Long-term prognostic role of flow-mediated dilatation of the brachial artery after acute coronary syndromes without ST elevation.

Coronary endothelial vasodilator dysfunction is associated with increased cardiac events; the close relation between coronary vasomotor dysfunction and brachial artery vasoreactivity has been previously described. This study assessed the prognostic value of noninvasively assessed brachial artery vasoreactivity in survivors of acute coronary syndromes without ST-segment elevation. We examined 98 men (63.1 +/- 10.8 years) who were referred to our hospital for acute coronary syndromes without ST-segment elevation. Brachial artery endothelium-dependent flow-mediated dilation (FMD) and endothelium-independent nitrate-mediated dilation were examined in all patients using high-resolution echocardiographic Doppler ultrasound within 24 hours of admission. Plasma malondialdehyde, a marker of oxidative stress, and left ventricular ejection fraction were also assessed. Twenty-seven patients underwent coronary revascularization. Patients were followed for 24.8 +/- 5.9 months. Cardiovascular death, myocardial infarction, stroke, and unstable angina were designated as cardiovascular events (CEs). Twenty CEs were recorded. Kaplan-Meyer analysis showed that patients with FMD <1.9% (tertile 1 of FMD values) were more likely to have CEs than those with FMD >1.9% (log rank 5.29, p = 0.021). Multivariate Cox regression analysis showed that FMD <1.9% predicted CEs with an adjusted hazard ratio of 3.035 (95% confidence interval 1.148 to 8.023, p = 0.025) after adjustment for age, risk factors, troponin T, ejection fraction, revascularization procedures, number of diseased vessels, and medication. In conclusion, endothelium-dependent dilation of the brachial artery is a strong independent predictor of adverse outcome in survivors of acute coronary syndromes without ST-segment elevation.

Acute Disease↗

PubMed2006

Abnormal endothelial function in female patients with hypothyroidism and borderline thyroid function.

BACKGROUND: It has been suggested that hypothyroidism is associated with an increased risk for cardiovascular disease. The aim of this study was to assess non-invasively NO-dependent endothelial function of resistance arteries in subjects with hypothyroidism of varying severity. METHODS: Ninety-six female subjects (aged: 42+/-13 years) comprised the study population. Subjects were divided into five groups based on TSH levels at presentation: Group 0 (n=23) with TSH: 0.3-2.0 microU/ml, Group 1 (n=22) with TSH: 2.1-4.0 microU/ml (upper normal), Group 2 (n=18) with TSH: 4.1-10 microU/ml (subclinical hypothyroidism), Group 3 (n=22) with TSH >10 microU/ml (overt hypothyroidism). One additional group with well-controlled hypothyroidism on L-thyroxine therapy (Group 4, n=11, TSH: 0.3-2.0 microU/ml) was also studied. Endothelial function of resistance arteries was assessed by measuring forearm blood flow response during reactive hyperemia utilizing venous occlusion strain-gauge plethysmography. RESULTS: Duration of reactive hyperemia was significantly different among groups of subjects with varying hypothyroidism (83.7+/-58.3 s, 53.2+/-35.7 s, 52.8+/-47.5 s, 12.9+/-13.3 s and 69.5+/-26.2 s in Groups 0, 1, 2, 3 and 4, respectively, p<0.001, ANOVA). Duration of reactive hyperemia was significantly shorter in subjects with upper normal TSH values (Group 1) compared to controls (53.2+/-35.7 s vs. 83.7+/-58.3 s, p=0.013), while it was comparable to that of subjects with subclinical hypothyroidism (Group 2) (52.8+/-47.5 s). However, duration of reactive hyperemia in Group 1 was significantly longer compared to Group 3 (overt hypothyroidism) (53.2+/-35.7 s vs. 12.9+/-13.3 s, p=0.002). Similarly, duration of reactive hyperemia in subjects with subclinical hypothyroidism was significantly longer compared to subjects with overt hypothyroidism (52.8+/-47.5 s vs. 12.9+/-13.3 s, p=0.003). Duration of reactive hyperemia in Group 4 (well-controlled hypothyroidism on L-thyroxine therapy) did not differ significantly compared to controls. There was a highly significant linear correlation between duration of reactive hyperemia and TSH (r=-0.383, p<0.001). CONCLUSION: Endothelial dysfunction was detected in the microvasculature of patients with hypothyroidism. Duration of reactive hyperemia decreased with increasing TSH levels. Since endothelial dysfunction is a factor leading to atherosclerosis, this abnormality may partly explain predisposition of patients with thyroid failure to cardiovascular disease.

Adult↗

PubMed2006

Circadian variation of arterial pressure wave reflections.

BACKGROUND: Various factors are implicated in the circadian pattern of cardiovascular vulnerability. The exact mechanisms involved in the peak incidence of cardiovascular events occurring during the early morning hours after awaking are not completely known. The purpose of our study was to investigate the circadian variation of timing and intensity of wave reflections in healthy individuals and to test the hypothesis that significant changes occur during the day. METHODS: Thirteen healthy non-smokers (seven women and six men, mean age 40.7 +/- 16.5 years) were examined. Aortic pulse wave analysis was performed to estimate surrogates of wave reflections intensity (augmentation index [AIx]) and timing. Twelve measurements separated by 1-h intervals were performed from 8 am to 7 pm each study day. RESULTS: Analysis of variance for repeated measures indicated significant changes during the 12-h period for heart rate corrected AIx (P = .033) and heart rate (P = .035). The AIx was maximal at 8 am within 1-h after awaking (17% +/- 3.6%); it was gradually diminished until 3 pm (9% +/- 4.1%) and again increased to a second (albeit lower) peak value during the late afternoon (7 pm). CONCLUSIONS: It is possible that the increased intensity of reflected waves occurring during the early morning in combination with the rising trend of blood pressure and heart rate at the same time results in an aggravated left ventricular afterload and an increase in myocardial oxygen demand. The morning-related enhancement of wave reflections may have potential implications for the increased risk for cardiovascular events during the early morning, which remains to be clarified.

Adult↗

PubMed2006

Impact of obesity in intima media thickness of carotid arteries.

OBJECTIVE: To explore differences in intima media thickness (IMT) of the carotid arteries induced by differences in BMI. RESEARCH METHODS AND PROCEDURES: Data from 3173 consecutive subjects, who were referred to our Hypertension Center from 1998 to 2004, were reviewed. Criteria for patients to be considered for further analysis included no past or concurrent antihypertensive medication, no concurrent medication with the potential to raise blood pressure (BP) (e.g., prednisone), and no clinical signs or laboratory evidence of secondary causes of hypertension. Our population was divided into four groups according to NIH criteria for obesity: underweight, normal weight, overweight, and obese. BMI, mean IMT of internal carotid arteries, and 24-hour BP values were available for all subjects. Five hundred thirty six subjects of the four groups, matched for age, gender, and mean 24-hour BP values, were included in the analysis. RESULTS: Mean IMT of internal carotid arteries was increased with increasing BMI. Mean IMT was significantly higher in obese subjects compared with normal-weight (p < 0.01) and underweight (p < 0.001) subjects. Mean IMT was significantly higher in overweight subjects compared with normal-weight ones (p < 0.05). Furthermore, multivariate regression analysis in obese subjects revealed that fasting serum glucose was independently associated with IMT. DISCUSSION: Obesity may be an important factor for carotid atherosclerosis, and at least some of the effects of obesity are independent of the BP levels. Fasting serum glucose levels in obese subjects may play an important role in carotid atherosclerosis.

Adult↗

PubMed2006

Arterial wave reflection is associated with severity of extracoronary atherosclerosis in patients with coronary artery disease.

BACKGROUND: Arterial wave reflection is a major determinant of left ventricular function, coronary perfusion and cardiovascular risk. We investigated whether arterial wave reflection may detect atherosclerosis of peripheral arteries in patients with documented coronary artery disease (CAD). METHODS: Radial artery applanation tonometry and pulse wave analysis was performed in 184 patients with documented CAD at coronary angiography; central blood pressures and augmentation index (AI) were measured. Ankle-brachial (ABI) index and intima-media thickness (IMT) were used as indices of atherosclerosis of the lower limbs and the carotid arteries respectively. RESULTS: Patients with abnormal IMT (> 0.7 mm, first tertile) or ABI (< 0.94, first tertile) had higher AI than patients with lower IMT or higher ABI (24 +/- 17 versus 17 +/- 16% and 23 +/- 18 versus 18 +/- 13%, respectively, P < 0.05). In multivariate analysis, increasing AI was associated with age, female gender, heart rate, mean blood pressure, hyperlipidaemia, and use of statins (regression coefficient (beta) = 0.50, beta = 0.15, beta = -0.60, beta = 0.23, beta = 0.16 and beta = -0.14, respectively, P < 0.05). Increasing AI was associated with an adjusted-odds ratio of 1.035 [95% confidence interval (CI), 1.005-1.066], P = 0.02 for an abnormal IMT and of 1.08 (95% CI, 1.024-1.146), P = 0.005 for ABI after adjustment for age, gender, heart rate, height, blood pressure, atherosclerotic risk factors, obesity and medication. No relation was found between AI and Gensini score or for the number of diseased coronary vessels. CONCLUSION: Augmentation index is a marker of extensive extracoronary atherosclerosis in patients with CAD.

Aged↗

PubMed2006

Genetic variations of the endothelial nitric oxide synthase gene are related to increased levels of C-reactive protein and macrophage-colony stimulating-factor in patients with coronary artery disease.

It was the objective of this study to investigate the relation between nitric oxide synthase (NOS3) gene polymorphisms, vascular inflammation, endothelial function, and atherosclerosis. We examined the effects of a variable nucleotide tandem repeats (VNTR) in intron 4, G894T in exon 7 and T-786C at the promoter region of NOS3 on i) C-reactive protein (CRP) and macrophage-colony stimulating-factor (MCSF), and ii) augmentation index (AI) measured by pulse-wave analysis , flow-mediated dilation (FMD) of the brachial artery, intima-media thickness (IMT) of the carotid and femoral artery using ultrasonography and ankle-brachial index (ABI) in 122 patients with chronic coronary artery disease (CAD) who underwent coronary angiography. MCSF and CRP were increased in patients withT-786C (77/122) or VNTR (40/122) allele compared to those without (F = 10.8, p = 0.002 and F = 3.8, p = 0.04 for T-786C and F = 3.65, p = 0.04 and F = 3.2 p = 0.049 forVNTR), even after adjustment for traditional risk factors and medication. Patients with combination of VNTR and T-786C (31/122) had higher MCSF or CRP than patients with one or none of these alleles (p < 0.05). Among patients with T-786C, those with MCSF>262 pg/ml or CRP>3.2 mg/l (n = 33/77) had a higher femoral and carotid IMT and number of plaques in the peripheral arteries than those with lower values of these inflammatory indices (p < 0.05). Patients with MCSF >262 pg/ml had also lower FMD and higher Gensini score than those with lower MCSF (p < 0.05). The intron 4-VNTR and T-786C mutation of NOS3 gene enhance the inflammatory process in patients with chronic CAD.

C-Reactive Protein↗

PubMed2005

Transmission of calibration errors (input) by generalized transfer functions to the aortic pressures (output) at different hemodynamic states.

BACKGROUND: Aortic pressure waveforms are calculated non-invasively by applying generalized transfer functions (GTF) to tonometric radial pressure waveforms. Input errors mainly during acquisition and calibration of tonometric pressures are "transferred" to aortic pressure calculation. The present study aimed to quantify the proportion of specific input errors which is "transferred" by the GTFs in a wide range of hemodynamic conditions and for different error combinations in brachial systolic (SBP) and diastolic (DBP) blood pressure measurements. METHODS: Aortic pulse wave analysis was performed in 103 subjects (52 normotensive and 51 untreated hypertensive) by the SphygmoCor System. Each pressure waveform was initially calibrated by sphygmomanometrical brachial pressures. Isolated, parallel and reverse errors in brachial SBP/DBP from -10 to +10 mmHg were simulated, by recalibration of the recorded radial pressure waveforms, inducing specific "errors" of GTF-input values. For every recalculated aortic SBP and DBP, the difference from the initial estimated value was considered to represent the "transferred error" to the aortic pressure estimation. RESULTS: Parallel errors by +/-5 mmHg in both SBP and DBP resulted to an identical change in GTF-derived aortic pressures, as expected. When an overestimation in SBP by 5 mmHg and an underestimation in DBP by -5 mmHg occurred (reverse errors), almost 56% of this error (approximately 2.8 mmHg) was transferred. An isolated error in brachial SBP by +/-5 mmHg was transmitted by 76% ( approximately 3.8 mmHg) to GTF-derived aortic SBP. In subjects with mean blood pressure>117 mmHg or with heart rates<74 bpm, a greater percent of the calibration error was transferred to GTF-derived blood pressures. CONCLUSIONS: Input errors in brachial pressure values result in a quantifiable effect on transfer function output (aortic pressures). The percent of the "error transfer" by the GTFs depends on heart rate and BP levels, which should be taken into account when applying GTFs at populations with different hemodynamic conditions.

Adult↗

PubMed2005

Arterial stiffness is increased in subjects with hypothyroidism.

BACKGROUND: The association between hypothyroidism and increased vascular resistance, arterial wall thickening and endothelial dysfunction is well recognized. The aim of the present study was to examine if hypothyroid subjects have increased arterial stiffness, a risk factor for cardiovascular morbidity and mortality. METHODS: Sixty-five subjects (59 females and 6 males) with normal thyroid function or hypothyroidism of varying degree were investigated by radial artery applanation tonometry and pulse wave analysis, for evaluation of arterial stiffness. RESULTS: Serum TSH values were positively correlated with central systolic blood pressure (r=0.258, p=0.037), central pulse pressure (r=0.316, p=0.010), augmentation pressure (r=0.299, p=0.015) and negatively with reflection time index (RTI), which indicates the pressure wave velocity (r=-0.311, p=0.012). Hypothyroid patients presented higher central systolic pressure and pulse pressure, higher augmentation pressure and lower RTI, indicating increased arterial stiffness in these subjects. RTI was independently related to age, central systolic pressure and TSH. Mild changes of arterial stiffness were observed even in subjects with TSH range 2.01-4.0 muU/ml suggesting that this group may have an early stage of mild thyroid failure. CONCLUSIONS: Hypothyroidism, even in the subclinical stage, is associated with changes in arterial stiffness. The observed abnormalities in arterial stiffness may have detrimental effects on left ventricular function and coronary perfusion in hypothyroid subjects.

Adult↗

PubMed2005

Arterial stiffness assessed by pulse wave analysis in essential hypertension: relation to 24-h blood pressure profile.

BACKGROUND: Arterial stiffness is a risk factor for cardiovascular morbidity and mortality and appears to be increased in arterial hypertension. The purpose of the present study was to relate systemic arterial stiffness assessed by pulse wave analysis to variables of 24-h ambulatory blood pressure monitoring (ABPM) in patients with essential hypertension. METHODS: Seventy-two subjects with untreated mild to moderate arterial hypertension underwent evaluation with 24-h ambulatory blood pressure monitoring. In the same subjects, applanation tonometry and pulse wave analysis was performed for evaluation of systemic arterial stiffness expressed as augmentation index and estimated aortic pulse wave velocity. RESULTS: Clinic systolic blood pressure, mean heart rate during 24-h blood pressure monitoring and height were independent predictors of augmentation index and estimated aortic pulse wave velocity. The 41 patients with blunted reduction in nighttime blood pressure (nondippers) showed higher mean systolic blood pressure (p=0.02), lower systolic and diastolic blood pressure variability (p<0.001), higher pulse pressure during 24-h monitoring (p=0.05) and higher estimated aortic pulse wave velocity (p=0.03), indicating stiffer arteries in this group. CONCLUSIONS: These results suggest that blood pressure change from day- to nighttime is an important determinant of arterial stiffness assessed by pulse wave analysis; this association could contribute to the higher cardiovascular risk in nondippers.

Blood Pressure Monitoring, Ambulatory↗

PubMed2005

Carotid artery intima-media thickness could predict the presence of coronary artery lesions.

The purpose of the present study was to examine whether intima-media thickness (IMT) predicts the presence of the coronary artery lesions independent of other risk factors including clinic blood pressure (BP), parameters of 24-h ambulatory BP monitoring, body mass index, serum cholesterol, and glucose levels. The study population consisted of 390 consecutive subjects who had recently undergone coronary arteriography; 51 subjects with no measurable lesions in their coronary arteries (control group) and 339 subjects with coronary artery lesions (coronary artery disease [CAD] group). Mean IMT of the common carotid artery (MCCA) and internal carotid artery (MICA) were significantly higher in subjects with CAD compare control subjects (P < .0001). Carotid IMT could predict the presence of coronary artery lesions independently of clinic or ambulatory BP values, BMI, serum cholesterol, and glucose levels (P < .01). Carotid IMT predicted the presence of significant coronary artery lesions with cutoff values 0.85 and 0.80 for MICA and MCCA, respectively. The IMT could be a clinical useful test for the presence of significant coronary artery lesions.

Adult↗

PubMed2005

Red wine acutely induces favorable effects on wave reflections and central pressures in coronary artery disease patients.

BACKGROUND: To investigate red wine's acute effects on aortic pressures and arterial stiffness in patients with coronary artery disease (CAD). METHODS: Fifteen patients with CAD were recruited in a double-blind, cross-over study, which was comprised of 2 study days. Each volunteer consumed either 250 mL of regular or 250 mL of dealcoholized red wine. Wave reflections, expressed as augmentation index (AIx), as well as central and peripheral blood pressures (BP) were assessed at fast and 30, 60, and 90 min postprandially. RESULTS: Both regular and dealcoholized red wine caused a significant decrease in AIx by 10.5% +/- 1.4% (P = .001) and 6.1% +/- 1.4% (P = .011), respectively, whereas no significant change was induced in mean BP and timing of wave reflections expressing pulse wave velocity. Peripheral systolic BPs remained unaltered in both beverages, whereas a significant decrease in peripheral and central diastolic BPs was observed after the dealcoholized red wine consumption (P = .03 and P = .035, respectively). Central systolic BP was decreased after the consumption of regular (-7.4 +/- 2.4 mm Hg, P = .05) and dealcoholized red wine (-5.4 +/- 2.7 mm Hg, P = .019). CONCLUSIONS: Both types of red wine provoked favorable acute effects on wave reflections and central systolic pressures, whereas no such effect was evident at the brachial artery. Therefore, these findings could be attributed mainly to red wine antioxidant substances, rendering it a possible means of at least acute attenuation of increased wave reflections, arterial stiffness, and central pressures in patients with coronary artery disease.

Adult↗

PubMed2004

Common carotid artery intima-media thickness in patients with brain infarction and intracerebral haemorrhage.

An increase in the intima-media thickness of the common carotid artery (CCA-IMT) is generally considered as an early marker of atherosclerosis and has been associated with a higher risk of stroke and myocardial infarction. There is no evidence of an association between the IMT and cerebral bleeding. We investigated cross-sectionally the diagnostic ability of vascular risk factors, including CCA-IMT, to distinguish between brain infarction (BI) and intracerebral haemorrhage (ICH). Patients suffering from BI (n = 126) had significantly (p < 0.05) higher CCA-IMT when compared to the ICH population (n = 30). The multinomial logistic regression procedure selected CCA-IMT as an independent factor able to discriminate between BI and ICH. The risk of BI versus ICH increased continuously with increasing CCA-IMT. After adjustment for cardiovascular risk factors the odds ratio for BI per 0.1 mm CCA-IMT increase was 1.29 (95% CI: 1.03-1.61). The present results demonstrate the possible predictive power of non-invasive measurement of the CCA-IMT with respect to BI versus ICH and deserve further investigation.

Aged↗

PubMed2004

Tamoxifen improves endothelial function and reduces carotid intima-media thickness in postmenopausal women.

BACKGROUND: Tamoxifen is a selective estrogen-receptor modulator shown to improve several cardiovascular risk factors in postmenopausal women with breast cancer. In animal studies tamoxifen inhibits the progression of atherosclerosis. Although the presence of a history with tamoxifen treatment is related to a lower intima-media thickness (IMT) of the common carotid artery, data from controlled follow-up studies are lacking to support this observation. METHODS: We examined 14 postmenopausal women with early stage breast cancer with indication for tamoxifen treatment (20 mg/d) and 13 healthy postmenopausal women. Flow-mediated dilatation (FMD) of the brachial artery, combined carotid IMT, and aortic pulse wave were measured before and 6 months after treatment in the tamoxifen group and at the same times in the control group. RESULTS: FMD and IMT were significantly increased and decreased, respectively, in the treatment group compared to the control group (FMD: +2.2% +/- 0.9% vs +0.085% +/- 1%, P =.012; IMT: -0.088 +/- 0.03 mm vs +0.04 +/- 0.03 mm, P =.018, mean +/- standard error of the mean, treatment vs control group). These differences remained significant even when adjusted for age, duration of menopause, and cardiovascular risk factors. Low-density lipoprotein cholesterol was also significantly reduced after tamoxifen treatment. CONCLUSIONS: Tamoxifen treatment slows the progression of atherosclerosis in postmenopausal women with breast cancer as assessed by changes in carotid IMT. An improvement in endothelial function and blood lipid profile may be the reason for this beneficial effect.

Aged↗

PubMed2004

Cardiac hypertrophy in hypertension: relation to 24-h blood pressure profile and arterial stiffness.

BACKGROUND: In subjects with essential hypertension peripheral blood pressure profile contributes to the pathogenesis of left ventricular hypertrophy. It is not known if central arterial pressure is superior to peripheral blood pressure profile for predicting left ventricular hypertrophy. In the present study 24-h blood pressure profile and central hemodynamics were examined to evaluate mechanical loading factors as determinants of cardiac hypertrophy in mild to moderate untreated essential hypertension. METHODS: Forty-eight untreated subjects with mild to moderate essential hypertension were examined by echocardiography for evaluation of left ventricular mass, 24-h ambulatory blood pressure monitoring (ABPM), and applanation tonometry of the radial artery with pulse wave analysis for evaluation of central hemodynamics. RESULTS: Left ventricular mass showed a statistically significant correlation with age, clinic systolic blood pressure, mean heart rate and heart rate variability during 24-h ABPM, augmentation pressure and index and central systolic blood pressure. In a multiple regression analysis including clinic systolic blood pressure, central systolic pressure, mean systolic pressure and pulse pressure during ambulatory monitoring as well as age, independent predictors of left ventricular mass were only age (P=0.006) and central systolic blood pressure (P=0.04). In conclusion, pulse wave analysis is a valuable method in predicting cardiac hypertrophy in untreated mild to moderate essential hypertension. Central systolic blood pressure should be taken into account for planning therapeutic strategies for prevention of left ventricular hypertrophy in hypertensive patients.

Arteries↗

PubMed2004

Oral folic acid enhances endothelial function in patients with hypercholesterolaemia receiving statins.

BACKGROUND: Folic acid therapy has been shown to improve endothelial function in patients with familial hypercholesterolaemia via a possible antioxidant mechanism. Data on the possible role of folic acid in hypercholesterolaemic patients receiving statins are lacking. In the present study we tested the hypothesis that folic acid supplementation improves endothelial function in patients with hypercholesterolaemia and treatment with statins. METHODS: Thirty-four hypercholesterolaemic patients receiving statins participated in the study; all subjects underwent measurement of endothelium-dependent, flow-mediated dilatation of the brachial artery and subsequently randomized to receive 5 mg of the folic acid (n=17) or placebo (n=17) for 4 weeks. Flow-mediated dilatation of the brachial artery was repeated at the end of the 4-week period. RESULTS: Folic acid and placebo groups were comparable regarding age, sex, smoking, hypertension, coronary artery disease, obesity, family history and blood lipids. Folic acid administration resulted in an improvement of flow-mediated dilatation (4.7+/-3.2% to 7.1+/-3.1%, P=0.02), whereas there was no improvement after placebo administration (5.7+/-3.8% to 5.6+/-2.2%, ns). No significant change in nitrate-induced, endothelium- independent dilatation was observed after folic acid or placebo (ns). CONCLUSIONS: Oral administration of folic acid (5 mg) for 4 weeks improves endothelial function in patients with hypercholesterolaemia treated with statins, with possible beneficial effects on the prognosis of these patients.

Administration, Oral↗

PubMed2004

Effect of ascorbic acid on forearm reactive hyperaemia in patients with hypercholesterolaemia.

BACKGROUND: This study was designed to research the effect of hypercholesterolaemia and ascorbic acid on forearm blood flow (FBF) reactive hyperaemia (RH). Reactive hyperaemia seems to be at least partly endothelium-dependent. Endothelial dysfunction has been described in patients with hypercholesterolaemia, and has been reversed with ascorbic acid administration. METHOD: Forearm blood flow was studied with venous occlusion plethsmography in 26 healthy volunteers and 46 hypercholesterolaemic patients. Hypercholesterolaemic patients were divided into two groups. Group A comprised 25 patients, who received ascorbic acid and group B comprised 21 patients, who received placebo. All subjects underwent measurement of FBF at baseline and during RH (phase A). Forearm blood flow during RH was measured every 15 seconds for three minutes. Subsequently patients in group A received 2 g of ascorbic acid orally in the form of effervescent tablets, and patients in group B received placebo orally in the same form. Forearm blood flow measurements at baseline and during RH were repeated two hours later (phase B). RESULTS: Maximal percent increase of FBF was significantly higher in healthy subjects than in hypercholesterolaemic patients (139.1+/-12.1% versus 73.1+/-11.0% respectively, P<0.05). Duration of RH was smaller in hypercholesterolaemic patients compared to normal subjects (60.9+/-17.1 seconds versus 105.6+/-10.2 seconds, P<0.05). Administration of ascorbic acid but not of placebo increased the duration of RH (69.1+/-11.1 seconds versus 104.1+/-12.2 seconds, P<0.05) but not of peak RH FBF. CONCLUSION: Hypercholesterolaemia seems to impair both the early and late phase of RH. Ascorbic acid improves only the duration of RH, possibly due to its antioxidant effect on endothelium.

Adult↗