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Biomedical subjects

Dimitri P Mikhailidis

Publications and source records attributed to Dimitri P Mikhailidis.

At least 55 records · Page 3Linked to original sources
PubMed2005

Effect of statins and aspirin alone and in combination on clinical outcome in dyslipidaemic patients with coronary heart disease. A subgroup analysis of the GREACE study.

DECLARATION OF INTEREST: The GREACE study was conducted independently; no Company or Institution has supported it financially. Some of the authors have attended conferences and participated in other trials sponsored by various pharmaceutical companies. We assessed the possible 'synergy' of statins and aspirin (ASA) in reducing vascular events in patients with coronary heart disease, in a post hoc analysis of the GREek Atorvastatin and Coronary-heart-disease Evaluation (GREACE) study. All patients (n = 1600) were divided into four groups according to long-term treatment: Group A (n = 787; statin + ASA), B (n = 93; statin - no ASA), C (n = 599; no statin - on ASA) and D (n = 121; no statin - no ASA). From all patients 692 were either on a statin or ASA monotherapy (Groups B + C). Relative risk reductions (RRRs) in 'all events' (primary endpoint) between groups were assessed. During the 3-year follow-up there were 292 cardiovascular events; 92 (12% of patients) in Group A, 14 (15%) in group B, 144 in Group C (24%) and 42 events in Group D (35%). The total number of events in Group B + C was 158 (23%). The RRRs in the primary endpoint were: Group A versus B 24% (P = 0.1912), A versus C 51% (P < 0.0001), A versus B + C 49% (P < 0.0001) and A versus D 71% (P < 0.0001). The RRRs in Group B versus C was 36% (P = 0.0431) and B versus D 57% (P = 0.0012), while in C versus D 33% (P = 0.0084). Our findings show that statins and ASA have an additive effect in reducing cardiovascular events. Aggressive statin use in the absence of ASA also substantially reduced cardiovascular events. Treatment with ASA in the absence of statin use reduced clinical events in comparison to patients not treated with either drug.

Adult↗
PubMed2005

Increased platelet purinergic sensitivity in peripheral arterial disease--a pilot study.

Peripheral arterial disease (PAD) is associated with platelet hyperaggregability as well as an increase in morbidity and mortality from myocardial infarction (MI) and stroke. Purinergic signaling has been shown, both experimentally and clinically, to play an important role in the activation of platelets. Platelets express three different purinergic receptors: P2Y1, P2Y12 and P2X1. We assessed the hypothesis that the hyperaggregability associated with PAD is partly due to an increased P2 receptor expression at the transcriptional and/or translational level. Patients with PAD (n=8) and controls (n=8) were studied. Using a high-resolution channelyzer, platelet shape change (PSC) was assessed by measuring the median platelet volume (MPV). The fall in free platelet count following the addition of ADP was also assessed. Real-time PCR was used to quantify the mRNA expression and Western blots to quantify the protein expression of P2 receptors in platelets. The median (and range) fall in free platelet count after adding ADP was significantly (P=0.02) greater for patients [11% (5-24); n=8] than for controls [0.5% (0-10); n=8] despite using a lower concentration of ADP for the patient samples. The MPV did not differ significantly. The mRNA levels for the three P2 receptors were similar in PAD patients and controls. Western blot detected no significant differences in protein expression between these groups. Thus, platelets from PAD patients show an increased activation after stimulation with ADP (even though all patients were on aspirin). This hyperactivity was neither due to an obvious up-regulation of the mRNA levels nor to altered protein levels of P2 receptors in the platelets. It is suggested that the increased sensitivity to ADP in PAD is caused by post-receptor mechanisms.

Adenosine Diphosphate↗
PubMed2005

Effect of antihypertensive treatment on plasma fibrinogen and serum HDL levels in patients with essential hypertension.

The influence of hypertension, and its treatment, on circulating lipid and fibrinogen (Fib) concentrations in patients with essential hypertension was investigated. The lipid profile and Fib levels were measured in 353 patients (131 men) with essential hypertension. Their median age was 60 years (range: 18-85 years). All patients had normal results from liver, renal, and thyroid function tests. There were 162 patients (45.9%) who were not receiving antihypertensive treatment. Of the remaining patients, 117 were taking 'lipid-hostile' beta-blockers, thiazide diuretics) antihypertensives and 74 were taking 'lipid-neutral' (angiotensin-converting enzyme inhibitors, calcium channel blockers, angiotensin-II receptor blockers) agents. Patients who were taking 'lipid-hostile' antihypertensive drugs had significantly higher plasma Fib concentrations when compared with those taking 'lipid-neutral' antihypertensives or those not receiving antihypertensive treatment. These differences were not attributable to established factors that influence plasma Fib levels, since when smokers and patients with diabetes mellitus and/or vascular disease were excluded, the difference remained significant. In addition, in these more homogeneous groups, patients receiving 'lipid-neutral' treatment had significantly higher serum high-density lipoprotein (HDL) cholesterol levels when compared with both those taking 'lipid-hostile' antihypertensives and untreated ones. There were no significant differences in the other lipid variables, independently of the presence/absence or the type of antihypertensives. These results suggest that antihypertensive drugs have additional effects, beyond lowering blood pressure, on other vascular risk factors, like Fib and HDL. These effects may depend on the type of drug used.

Adolescent↗
PubMed2005

A review of the lipid-related effects of fluvastatin.

BACKGROUND: Statin therapy has been shown to significantly decrease vascular events and overall mortality in primary and secondary prevention trials. This review considers the pharmacology, nonlipid-lowering effects and clinical trial evidence of fluvastatin based on a survey of PubMed entries. FINDINGS: Recent clinical data show that treatment with fluvastatin is associated with a variety of benefits in different high-risk populations along with a good safety profile. Fluvastatin exerts non-lipid lowering-associated pleiotropic effects in both clinical and experimental studies. Furthermore, an extended-release formulation of fluvastatin with a favourable pharmacokinetic profile is available. CONCLUSION: Treatment with fluvastatin offers a convenient, safe and evidence-based approach to managing dyslipidaemias and preventing vascular events.

Coronary Artery Disease↗
PubMed2005

The involvement of professional medical writers in medical publications.

In this editorial, we comment on the European Medical Writers Association (EMWA) guidelines and the accompanying Delphi study published in this issue of Current Medical Research and Opinion. These articles deal with 'ghost writing' and the role of professional writers. We propose that the interaction between professional writers and authors is defined along the following principles: Guarantee: are the authors guarantors of the article? Advice: was the professional writer 'advised' by the author(s) before, as well as after, starting the assignment? Were the overall conclusions defined by the author(s)? Transparency: the contribution of professional writers should be acknowledged (we provide a draft statement). Expertise: does the professional writer have sufficient knowledge in the relevant specific field? The initials of these headings form the word ' GATE '. Therefore, we called them the ' GATE principles '. We also discuss suggestions for the accreditation of professional writers in specific fields. Professional writers play a useful role but this has to be clearly defined so as to achieve high ethical and scientific standards.

Accreditation↗
PubMed2005

The prevalence of the metabolic syndrome using the National Cholesterol Educational Program and International Diabetes Federation definitions.

OBJECTIVE: The prevalence of metabolic syndrome (MetS), using the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) and International Diabetes Federation (IDF) definitions, was compared in 9669 subjects, representing the Greek population. RESULTS: The age-adjusted prevalence of NCEP ATP III-defined MetS was 24.5% whereas that of IDF-defined MetS was 43.4% (+77%,p < 0.0001). The majority (up to 69%) of older age groups had IDF-defined MetS. The calculated vascular event risk was low (6.1% and 7.2% using the Framingham and PROCAM calculation, respectively) in those with IDF-defined MetS when compared with those with NCEP ATP III MetS (11.3% and 13.7%, respectively) (p < 0.0001 for both comparisons). CONCLUSION: MetS could be considered as a 'normal' variant if it was present in the majority of the population. Moreover, the vascular risk associated with IDF-defined MetS could be low, raising cost-effectiveness issues. Alternatively, the new IDF definition may realistically reflect the current MetS epidemic. More studies are required to support or refute those interpretations.

Adolescent↗
PubMed2005

Peripheral arterial disease: a missed opportunity to administer statins so as to reduce cardiac morbidity and mortality.

Peripheral arterial disease (PAD) is a common condition associated with an increased risk of coronary heart disease, myocardial infarction and stroke. It follows that PAD merits aggressive preventive treatment that includes lipid lowering drugs (mainly statins). This review summarises the current knowledge concerning the use and mechanisms of action of statins in patients with PAD. Statins not only lower the risk of vascular events, but they also improve the symptoms associated with PAD. There is also evidence that statins reduce surgical mortality and improve graft patency and limb salvage. Because of the high risk, a more aggressive goal [i.e. low density lipoprotein cholesterol (LDL-C) of 70 mg/dl; 1.8 mmol/l] [National Cholesterol Education Program (NCEP) Adult Treatment Panel III (ATP III), revised guidelines 2004] should be considered to maximally reduce the atheroma burden and related events. Not all statins can achieve this LDL-C target. Furthermore, there may be a need to use an additional lipid lowering drug so as to achieve the LDL-C goal and benefit from the different modes of action. Statins exert beneficial pleiotropic effects on haemostasis, the vasculature and inflammatory markers. There is also evidence that statins improve renal function (the plasma creatinine level is considered as an emerging vascular risk factor). Since PAD patients often take several drugs, there is a need to carefully consider their selection so as to maximize benefits and minimize adverse effects. Patients with PAD often do not receive adequate lipid lowering treatment. This situation needs to change.

Arteries↗
PubMed2005

Clinical relevance of postprandial lipaemia.

Several studies showed that after a fatty meal, plasma triglyceride (TG) levels are higher in patients with coronary heart disease. This abnormality may explain why some individuals develop atherosclerotic disease despite normal fasting lipid values. TG-rich lipoproteins are involved in atherosclerosis and thrombosis. TG, remnant-like particle (RLP) cholesterol (RLP-C) and RLP-TG increase after fat load and could contribute to atherothrombosis. Postprandial lipaemia is not a uniform abnormality. Its pathophysiology is not yet entirely clarified; possibly, the response to dietary fat is a polygenic phenomenon. However, a link with insulin resistance is likely; this link as well as that with obesity is discussed. A substantial part of life is spent in the postprandial state. Therefore, several investigators described fat load tests. However, it is still difficult to establish normal postprandial TG ranges since only small numbers of subjects were studied and there is as yet no standardised method. A more simplified fat load test should be established for 'routine' use. In this review, we consider the metabolic features, prevalence and management of postprandial lipaemia. Treatment may involve lifestyle measures as well as the use of lipid lowering (e.g. fibrates or statins), weight reducing and hypoglycaemic drugs.

Cholesterol↗
PubMed2005

Fenofibrate: metabolic and pleiotropic effects.

Disturbances of lipoprotein metabolism represent one of the most important risk factors for vascular events. However, dyslipidaemic patients often have a number of additional abnormalities (such as endothelial dysfunction, hypertension, low-grade inflammation, haemostatic abnormalities and hyperuricaemia) that may accelerate the atherosclerotic process. Thus, the ideal lipid-modifying drug, along with exerting beneficial effects on lipoprotein metabolism, should also improve these coexisting disturbances. Fibric acid derivatives (fibrates) are a class of lipid-modifying drugs mainly used in patients with elevated triglyceride levels. These drugs mainly exert their actions via the activation of specific nuclear receptors called peroxisome proliferator-activated receptors alpha (PPARalpha). In this review, we summarize the current evidence suggesting that fenofibrate, one of the most widely used fibric acid derivatives, along with its well established actions on lipids also exerts several other antiatherogenic actions. Based on recently published studies, fenofibrate is a useful option for patients with primary combined dyslipidaemias or secondary dyslipidaemias, such as those associated with diabetes mellitus, metabolic syndrome or HIV infection. Additionally, in cases of refractory dyslipidaemia, the combination of fenofibrate with statins is a therapeutic option.

Anti-Inflammatory Agents↗
PubMed2005

Endothelin-1 and human platelets.

There is conflicting evidence regarding the effect of endothelin-1 (ET-1) on platelets. Some studies show that ET-1 activates platelets, others show platelet inhibition with ET-1 and some studies did not detect an effect of ET-1. These conflicting results may be due to complex interactions between platelet ET(A) and ET(B) receptors. ET-1 antagonism may emerge as an important therapeutic strategy in the management of several vascular disorders. However, to date the only prescribed ET-1 antagonist is bosentan for pulmonary arterial hypertension. Bosentan is a 'dual' ET-1 antagonist (i.e. it acts on both ET(A) and ET(B) receptors). Whether this action involves an effect on platelets remains to be established. In this review some of the studies describing the effect of ET-1 on human platelets are discussed. Vascular diseases where ET-1 is implicated are also considered.

Animals↗
PubMed2005

The role of serotonin in tumour growth (review).

Serotonin (5-hydroxytryptamine; 5HT) a monoamine neurotransmitter mediates a wide range of physiological actions in the human body. For example 5HT is implicated in psychiatric and neurological disorders and also plays a fundamental role in tumour growth, differentiation and gene expression. 5HT acts as a growth factor for several types of tumoural and non-tumoural cells. This review considers the role of 5HT and its receptors in the human body with particular reference to carcinogenesis. We conclude that 5HT causes growth proliferation and 5HT antagonists cause growth inhibition in a variety of tumour cells (e.g. prostate carcinoma, lung carcinoma and colonic carcinoma). Therefore, further studies should look into the potential use of 5HT antagonists in the treatment of cancer.

Cell Line, Tumor↗
PubMed2004

Effect of tibolone on markers of cardiovascular disease risk in postmenopausal women undergoing hemodialysis: a pilot study.

OBJECTIVE: To assess the effect of tibolone on markers of vascular risk in postmenopausal women who were receiving hemodialysis. DESIGN: One-year open-label study. SETTING: "Zvezdara" University Medical Center, Belgrade, Serbia. PATIENT(S): Twenty-eight postmenopausal women undergoing chronic hemodialysis. INTERVENTION(S): Fifteen women received tibolone 2.5 mg three times per week; 13 other women served as controls. MAIN OUTCOME MEASURE(S): Mean arterial pressure and weight were measured at baseline and at 6 and 12 months, and blood was collected for insulin, total cholesterol, low-density lipoprotein, high-density lipoprotein, triglycerides, lipoprotein(a), high-sensitivity C-reactive protein (hs-CRP), endothelin-1 (ET-1), vascular endothelial growth factor (VEGF), and markers of renal function. RESULT(S): Mean arterial pressure fell in the tibolone but not in the control group at 6 and 12 months versus baseline (mean [SD]: 93 [15] vs. 105 [11] mmHg and 94 [10] vs. 105 [11] mmHg, respectively). Weight, insulin, lipids, lipoprotein(a), hs-CRP, ET-1, VEGF, and renal function remained unchanged within each group, but high-density lipoprotein concentrations fell in the tibolone group after 12 months (1.2 [0.3] vs. 1.6 [0.6] mmol/L). CONCLUSION(S): The effects of tibolone on markers of vascular risk in postmenopausal women who are receiving hemodialysis and healthy women appear to differ. This should be taken into account when tailoring menopausal therapies to the specific requirements of each individual.

Antihypertensive Agents↗
PubMed2004

Effect of statins versus untreated dyslipidemia on serum uric acid levels in patients with coronary heart disease: a subgroup analysis of the GREek Atorvastatin and Coronary-heart-disease Evaluation (GREACE) study.

BACKGROUND: Little is known about the effect of dyslipidemia on serum uric acid (SUA) levels, and less is known about the effect of statin treatment on them. The GREek Atorvastatin and Coronary-heart-disease Evaluation study suggested that a mean atorvastatin dose of 24 mg/d achieves the National Cholesterol Educational Program treatment goals and significantly reduces morbidity and mortality in patients with coronary heart disease (CHD) in comparison to the usual care. Here, we report the time course of SUA levels in usual-care patients undertreated for their dyslipidemia (12% were administered statins) in comparison to structured-care patients treated with atorvastatin in the vast majority (98%). METHODS: Mean on-study SUA levels (up to 48 months) were compared with those at baseline by using analyses of variance to assess differences over time within and between treatment groups. Cox multivariate analysis was used to investigate whether changes in SUA levels during the study were clinically relevant. RESULTS: All patients had normal renal function at baseline; serum creatinine (SCr) levels less than 1.3 mg/dL (<115 micromol/L) and moderately elevated SUA levels (mean, 7.1 +/- 0.9 [SD] mg/dL [425 +/- 52 micromol/L]; upper normal limit, 7.0 mg/dL [415 micromol/L]). Usual-care patients (n = 800) showed an increase in SUA levels by 3.3% ( P < 0.0001). Structured-care patients (n = 800) had an 8.2% reduction in SUA levels ( P < 0.0001). In all patients not administered diuretics (n = 1,407), SUA level changes showed a positive correlation with changes in SCr levels ( r = 0.82; P < 0.0001) and an inverse correlation with estimated glomerular filtration rate ( r = -0.77; P < 0.0001). After adjustment for 19 predictors of all CHD-related events, Cox multivariate analysis involving backward stepwise logistic regression showed a hazard ratio (HR) of 0.89 (95% confidence interval [CI], 0.78 to 0.96; P = 0.03) with every 0.5-mg (30-micromol/L) reduction in SUA level, an HR of 0.76 (95% CI, 0.62 to 0.89; P = 0.001) with every 1-mg (60-micromol/L) reduction, an HR of 1.14 (95% CI, 1.03 to 1.27; P = 0.02) with every 0.5-mg increase, and an HR of 1.29 (95% CI, 1.17 to 1.43; P = 0.001) with every 1-mg increase in SUA levels. CONCLUSION: Data suggest that SUA level is an independent predictor of CHD recurrent events. Atorvastatin treatment significantly reduces SUA levels in patients with CHD, thus offsetting an additional factor associated with CHD risk.

Aged↗
PubMed2004

The effect of clopidogrel, aspirin and both antiplatelet drugs on platelet function in patients with peripheral arterial disease.

Peripheral arterial disease (PAD) is associated with platelet hyperactivity. Aspirin and clopidogrel, two platelet inhibitors, act by different mechanisms. Aspirin inhibits thromboxane A2 synthesis and clopidogrel acts on the P2Y12 platelet ADP receptor. We evaluated the effect of clopidogrel (75 mg/day), aspirin (75 mg/day) and then both drugs on several platelet function indices in patients with PAD (n = 20). There was a significant (P = 0.0001) decrease in ADP-induced aggregation, after clopidogrel but not after taking aspirin. Clopidogrel plus aspirin significantly decreased spontaneous platelet aggregation (SPA) (P = 0.01 to P = 0.002) but SPA was not significantly altered by either aspirin or clopidogrel monotherapy. Similarly, monotherapy did not inhibit serotonin (5HT)-induced aggregation but there was a sigificant inhibition (P = 0.03 to P < 0.02) after combination therapy. ADP (0.8 microM)-induced platelet shape change (PSC) was significantly inhibited by clopidogrel (P = 0.004) or aspirin (P = 0.01). This was also true for 5HT-induced PSC (clopidogrel, P = 0.01; aspirin, P = 0.03). Soluble P-selectin decreased significantly (from 32 +/- 24 to 25 +/- 17 ng/ml, P = 0.04) with combination therapy. Plasma platelet-derived growth factor and intraplatelet 5HT levels were not altered by combination therapy. In PAD, clopidogrel is a more potent inhibitor of ADP-induced platelet activation than aspirin; combination therapy is more effective than clopidogrel or aspirin monotherapy. These potentially clinically relevant findings should be evaluated in appropriately designed trials.

Adenosine Diphosphate↗
PubMed2004

The influence of natural menopause on postprandial lipemia in heterozygotes for familial hypercholesterolemia.

BACKGROUND: Heterozygous familial hypercholesterolemia (hFH) is a genetic disease that leads to premature atherosclerosis. Natural menopause leads to an adverse lipid profile and an enhanced risk of coronary heart disease (CHD). Raised plasma triglyceride (TG) levels also contribute to the risk of vascular events. The aim of this study was to evaluate the postprandial TG levels (after a standardized fatty meal) in premenopausal and postmenopausal women with hFH. METHODS: Thirty-three Greek women with hFH were divided into the premenopausal group--n = 16, mean age 34(SD = 7), mean total cholesterol = 330(30) mg/dl--and the postmenopausal group--n = 17, mean age 62(5), mean total cholesterol = 346(63) mg/dl. Plasma TG concentrations were measured before and 2, 4, 6, and 8 hours after a standardized fat load. A value of >219 mg/dl (2.5 mmol/L) was taken as an abnormal response to the fat load, according to our previous studies. RESULTS: Postmenopausal women had higher TG levels at 2 (p = 0.001), 4 (p = 0.003), 6 (p = 0.003), and 8 hours (p = 0.005) after the fatty meal compared to premenopausal women. Forty-one percent of postmenopausal hFH women had abnormal TG response (hFH-A) after a fatty meal, and such women had higher fasting TG levels than postmenopausal hFH women with a normal response to the fatty meal (hFH-N) (p = 0.0014). CONCLUSIONS: Women with hFH tend to have an abnormal TG response to a fatty meal after the menopause. Fasting TG levels may be able to predict the abnormal response to a fatty meal.

Adult↗