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Biomedical subjects

Anthony S Wierzbicki

Publications and source records attributed to Anthony S Wierzbicki.

At least 19 recordsLinked to original sources
PubMed2007

Differential effect of pioglitazone (PGZ) and rosiglitazone (RGZ) on postprandial glucose and lipid metabolism in patients with type 2 diabetes mellitus: a prospective, randomized crossover study.

BACKGROUND: Postprandial metabolism is impaired in patients with type 2 diabetes (T2Dm). Two thiazolidinediones pioglitazone (PGZ) and rosiglitazone (RGZ) have similar effects on glycaemic control but differ in their effects on fasting lipids. This study investigated the effects of RGZ and PGZ on postprandial metabolism in a prospective, randomized crossover trial. METHODS: Seventeen patients with T2Dm were randomized to RGZ or PGZ for 12 weeks, with an 8-week wash-out period. Fasting blood samples were taken for glucose (FPG), insulin, HbA(1c), lipids, apolipoproteins (apo), lipoprotein (LPL) and hepatic lipase (HL), and cholesterol ester transfer protein (CETP) activity. A standardized breakfast was served and postprandial glucose, insulin, and lipid subfraction profiles were determined. RESULTS: RGZ and PGZ treatment resulted in a similar improvement in FPG, HbA(1c) and homeostasis model assessment. Fasting and postprandial triglyceride (TG) levels were significantly lower following PGZ therapy (fasting: -0.35 vs 0.44 mmol/L; p < 0.04; postprandial AUC-TG: -195.6 vs 127.9 mmol/L/min; p < 0.02) associated with changes in VLDL-2-TG (-0.10 vs 0.21 mmol/L; p = 0.23) and VLDL-3-TG (0.0 vs 0.34 mmol/L; p < 0.04). Fasting cholesterol increased with RGZ compared to PGZ (0.06 vs 0.59 mmol/L; p < 0.04), particularly in VLDL-2-C (-0.30 vs 0.59 mmol/L; p < 0.03) and VLDL-3-C (-0.85 vs 2.11 mmol/L; p < 0.02). Postprandial VLDL lipid and protein content increased after RGZ and decreased after PGZ. Fasting apoB, apoA-I, apoC-II/C-III-ratio, and LPL activity did not differ. CETP activity decreased after RGZ and increased after PGZ (-6.2 vs 4.2 p/mol/mL/min; p < 0.002). CONCLUSIONS: Both the glitazones had similar effects on glucose metabolism. The additional beneficial effect of PGZ on lipid metabolism may be related to its effects on insulin-independent VLDL production and CETP activity.

Blood Glucose↗
PubMed2006

Cardiovascular risk factors determine erectile and arterial function response to sildenafil.

BACKGROUND: Erectile dysfunction is related to endothelial function. Cardiovascular risk factors determine endothelial function. Sildenafil is effective in treatment of erectile dysfunction but shows variable results. This study investigated the relationship of cardiovascular risk factors to acute and chronic responses to sildenafil. METHODS: Cardiovascular risk factors and acute and chronic pulse wave responses to a single 50-mg dose of sildenafil were assessed in 45 patients with erectile dysfunction confirmed by low international index of erectile function (IIEF) score before and after chronic therapy with sildenafil. RESULTS: On recruitment all patients showed evidence of erectile dysfunction with an IIEF score of 5 points (1 to 20 points). Chronic sildenafil therapy resulted in an increase of IIEF score of 13 points (range -1 to +24 points) and 24 patients (53%) achieved an IIEF score>or=21 points. Improvement in erectile function in response to sildenafil (rn=0.79; P<.001) was dependent on initial erectile function (P=.002) and baseline apolipoprotein B (P=.01). Vascular responses to acute treatment with sildenafil were assessed using pulse wave analysis. Acute changes in stiffness index induced by sildenafil (rn=0.65; P<.001) were related to apolipoprotein A-1 (P=.006), B (P=.02), and lipoprotein(a) (P=.008) concentrations, whereas reflection index (rn=0.69; P<.001) was related to pulse pressure (P<.001), albumin-to-creatinine ratio (P=.007), and lipoprotein(a) (P=.02). CONCLUSIONS: The extent of acute and chronic effects of sildenafil on erectile function and pulse wave profiles is determined by metabolic cardiovascular risk factors. Improved cardiovascular risk factor control is likely to increase the efficacy of phosphodiesterase-5 inhibitor therapy in the treatment of erectile dysfunction.

Aged↗
PubMed2006

Plasma lipid profiles of women with intrahepatic cholestasis of pregnancy.

OBJECTIVE: Intrahepatic cholestasis of pregnancy is associated with dyslipidemia, but the gestational lipid profile in relation to clinical diagnosis of the disease is unknown. The aim of this study was to undertake a detailed analysis of plasma lipids in women presenting with intrahepatic cholestasis of pregnancy and pruritus gravidarum. METHODS: Plasma lipid concentrations were assessed in nonfasting blood samples from 63 women with intrahepatic cholestasis of pregnancy (n = 54, recruited at the time of diagnosis, and n = 9, who later developed the disease), 43 women with pruritus gravidarum, and 26 healthy pregnant controls during pregnancy and at 4-6 weeks postpartum. RESULTS: Intrahepatic cholestasis of pregnancy was associated with an abnormal lipid profile. Low-density lipoprotein (LDL) cholesterol, apolipoprotein B-100, and total cholesterol concentrations were significantly raised during pregnancy in women with intrahepatic cholestasis of pregnancy compared with pruritus gravidarum and controls, and LDL-cholesterol was raised before clinical diagnosis. High-density lipoprotein cholesterol was lower in women with intrahepatic cholestasis of pregnancy compared with the pruritus gravidarum group. Ursodeoxycholic acid did not alter plasma lipid concentrations. CONCLUSION: Intrahepatic cholestasis is associated with dyslipidemia, which may contribute to the pathogenesis of the disease. The elevation of LDL cholesterol and reduction of high-density lipoprotein cholesterol before clinical diagnosis may prove to be a useful biomarker for the early identification of intrahepatic cholestasis of pregnancy and differentiation from pruritus gravidarum. LEVEL OF EVIDENCE: II-2.

Adult↗
PubMed2006

Low-density lipoprotein apolipoprotein B100 turnover in hypopituitary patients with GH deficiency: a stable isotope study.

BACKGROUND: Epidemiological studies suggest that hypopituitary patients have an increased risk for cardiovascular mortality. The dyslipidaemia associated with this condition is often characterised by an increase in total cholesterol (TC) and low-density lipoprotein (LDL) cholesterol (LDL-C) and may contribute to these findings. The underlying mechanisms are not fully elucidated. MATERIALS AND METHODS: LDL apolipoprotein B (apoB) production rate and metabolic clearance rate were measured in seven patients with hypopituitarism (including GH deficiency) under stable conventional replacement therapy (three males and four females; age 40-16.1 years; body mass index 29.0-6.1 kg/m(2) (means +/- s.d.)) and seven age-, gender- and body mass index-matched control subjects with an infusion of 1-(13)C-leucine. Fasting lipid profile and lipid composition of LDL were also measured. RESULTS: Fasting TC, triglycerides (TG), high-density lipoprotein-C, LDL-C and free fatty acid concentrations were not different between hypopituitary patients and control subjects. LDL-TG (P < 0.006) and LDL-TG/LDL apoB ratio (P < 0.02) were significantly increased in hypopituitary patients. LDL apoB pool size was not statistically different between patients and control subjects. In the hypopituitary patients, LDL apoB metabolic clearance rate (P < 0.05) and LDL apoB production rate (P < 0.02) were lower than in the control subjects. CONCLUSIONS: The present results suggest that LDL apoB turnover and LDL composition is altered in hypopituitary patients. Whether these findings explain the increased risk for cardiovascular disease in hypopituitary patients remains to be established.

Adult↗
PubMed2006

Fibrates after the FIELD study: Some answers, more questions.

Fibrates have a long history in cardiovascular disease. These drugs raise high-density lipoprotein (HDL)-cholesterol, reduce triglycerides and improve small dense low-density lipoprotein (LDL) so would be expected to have large effects in type 2 diabetes, where this is the typical lipid profile. The general trial results with these agents have been confusing, with varying cardiovascular benefits. The Fenofibrate Intervention and Endpoint Lowering in Diabetes (FIELD) study recruited a low-risk population with a lipid profile that would be more usually treated with a statin. FIELD showed a non-significant 11% reduction (p = 0.16) in the primary end point of coronary events and a significant 11% benefit on the secondary end point of cardiovascular events and procedures (p = 0.04). Most of the benefits were seen in primary prevention and non-fatal myocardial events. Fenofibrate had little effect on HDL-C; the effects of the trial are consistent with the LDL-C reducing potential of this drug. FIELD, because of unequal statin drop-in, gives little evidence on statin-fibrate combination therapy but does reinforce the available data on the safety of fenofibrate-statin combination therapy. In addition, fenofibrate showed possible benefits on microvascular disease end points, including albuminuria and retinopathy. On current data fenofibrate and gemfibrozil seem to be reasonable second-line agents in type 2 diabetes or secondary prevention with low HDL-C, respectively, based on outcome evidence. In combination therapy, drug-specific safety considerations will affect the exact choice of agent, especially in combination with statins, but the efficacy of combination therapy still requires validation in the Action to Control Cardiovascular Risk in Diabetes (ACCORD) study.

Cardiovascular Diseases↗
PubMed2005

Mutational analysis in UK patients with a clinical diagnosis of familial hypercholesterolaemia: relationship with plasma lipid traits, heart disease risk and utility in relative tracing.

As part of a randomised trial [Genetic Risk Assessment for Familial Hypercholesterolaemia (FH) Trial] of the psychological consequences of DNA-based and non-DNA-based diagnosis of FH, 338 probands with a clinical diagnosis of FH (46% with tendon xanthomas) were recruited. In the DNA-based testing arm (245 probands), using single-strand conformation polymorphism of all exons of the low-density lipoprotein receptor (LDLR) gene, 48 different pathogenic mutations were found in 62 probands (25%), while 7 (2.9%) of the patients had the R3500Q mutation in the apolipoprotein B (APOB) gene. Compared to those with no detected mutation, mean untreated cholesterol levels in those with the APOB mutation were similar, while in those with an LDLR mutation levels were significantly higher (None=9.15+/-1.62 vs LDLR=9.13+/-1.16 vs APOB=10.26+/-2.07 mmol/l p<0.001, respectively). Thirty seven percent of the detected mutations were in exon 3/4 of LDLR, and this group had significantly higher untreated cholesterol than those with other LDLR mutations (11.71+/-2.39 mmol/l vs 9.88+/-2.44 mmol/l, p=0.03), and more evidence of coronary disease compared to those with other LDLR or APOB mutations (36 vs 13% p=0.04). Of the probands with a detected mutation, 54 first-degree relatives were identified, of whom 27 (50%) had a mutation. Of these, 18 had untreated cholesterol above the 95th percentile for their age and gender, but there was overlap with levels in the non-carrier relatives such that 12% of subjects would have been incorrectly diagnosed on lipid levels alone. In the non-DNA-based testing arm (82 probands) only 19 of the 74 relatives identified had untreated cholesterol above the 95th percentile for their age and gender, which was significantly lower (p<0.0005) than the 50% expected for monogenic inheritance. These data confirm the genetic heterogeneity of LDLR mutations in the UK and the deleterious effect of mutations in exon 3 or 4 of LDLR on receptor function, lipids and severity of coronary heart disease. In patients with a clinical diagnosis of FH but no detectable mutation, there is weaker evidence for a monogenic cause compared with relatives of probands with LDLR mutations. This supports the usefulness of DNA testing to confirm diagnosis of FH for the treatment of hyperlipidaemia and for further cascade screening.

Cardiovascular Diseases↗
PubMed2005

Asymmetric dimethyl arginine levels correlate with cardiovascular risk factors in patients with erectile dysfunction.

BACKGROUND: Erectile dysfunction is related to penile arterial endothelial nitric oxide production. Asymmetric dimethylarginine (ADMA) and E-selectin are often considered plasma markers of endothelial function. OBJECTIVE: This study investigated the relationship between these plasma markers and cardiovascular risk factors in patients with erectile dysfunction. METHODS AND RESULTS: Cardiovascular risk factors, ADMA and E-selectin were assessed in 45 patients with erectile dysfunction. Plasma markers showed associations with baseline risk factors. E-selectin levels showed an inverse relationship with age (p = 0.005) and statin therapy (p = 0.03) and a weak association with concomitant beta-blocker therapy (p = 0.05). Compared to these relatively weak associations with cardiovascular risk factors, ADMA levels showed strong associations with pulse pressure (p < 0.001), lack of smoking (p = 0.002) and lipoprotein (a) (p = 0.004) concentrations and weak associations with LDL-cholesterol (p = 0.02), and C-reactive protein levels (p = 0.04). ADMA levels correlated with E-selectin (partial r = 0.76; p < 0.001) after adjustment for lipoprotein (a), pulse pressure and smoking. No change in E-selectin or ADMA levels was seen after 70 days therapy with sildenafil and no relationship was found between either plasma marker and the acute pulse wave response to a single challenge dose of sildenafil. CONCLUSION: ADMA levels correlate at baseline with some cardiovascular risk factors including inflammatory markers and lipoprotein (a) in patients with erectile dysfunction.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed2005

Have we forgotten the pivotal role of high-density lipoprotein cholesterol in atherosclerosis prevention?

The critical importance of high-density lipoprotein cholesterol (HDL-C) as an independent and predictive factor for coronary heart disease (CHD) has been increasingly recognised in treatment guidelines for prevention and treatment of cardiovascular disease. The association of low HDL-C with an increased incidence of CHD implies a critical role for raising HDL-C in protection against atherosclerotic disease. HDL-C appears to exert this effect via a number of mechanisms. HDL-C is involved in reverse cholesterol transport, prevents endothelial dysfunction and has anti-inflammatory, anti-oxidant and antithrombotic properties. Therapeutic interventions that increase HDL-C include statins, fibrates and nicotinic acid. Of these, nicotinic acid raises HDL-C more effectively than either statin or fibrate therapy and has been proven to reduce cardiovascular events in monotherapy studies. Preliminary clinical studies have shown that addition of nicotinic acid to primary statin therapy is safe, has proven beneficial effects on atherosclerosis and may also reduce the incidence of major coronary events. The available clinical evidence suggests that addition of nicotinic acid to primary lipid-lowering therapy has an important atheroprotective role in patients with or at risk of developing CHD.

Arteriosclerosis↗
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

Efficacy of ezetimibe in patients with statin-resistant and statin-intolerant familial hyperlipidaemias.

OBJECTIVE: To investigate the efficacy of the cholesterol absorption inhibitor ezetimibe in patients with refractory familial hyperlipidaemia or intolerant to statin therapy. METHODS: This prospective study assessed the safety and efficacy of ezetimibe in 200 patients with refractory familial hyperlipidaemias not achieving a low-density-lipoprotein (LDL) cholesterol < 3 cholesterol < 3 mmol/L (116 mg/dL) including 22% intolerant to all statin therapy, many consuming intolerant to all statin therapy, many consuming sterol-containing products. RESULTS: Ezetimibe monotherapy resulted in 7% and 11% reductions in LDL-cholesterol and apolipoprotein B respectively. Ezetimibe-statin combination therapy reduced LDL-cholesterol by an additional 11 +/- 27% and apolipoprotein B by 11 (+79 to -18)%. There was a similar response between various sub-groups but a wide variation within groups with the greatest effect seen in patients groups with the greatest effect seen in patients under-responding to statins. The number of patients achieving the LDL-C target of 3 mmol/L rose from 5.5% to 18%. Non-significant effects included a 5 (+78 to -470)% reduction in triglycerides, 8 +/- 36% increment in HDL-cholesterol, 21 (+35 to -82)% reduction in C-reactive protein and a 1 (+20 to -50)% increase in alanine transaminase. No effects were seen on creatinine, creatine kinase, or insulin resistance. Fourteen patients (7%) discontinued ezetimibe: seven due to gastrointestinal side-effects, one patient developed an ezetimibe-induced hypercholesterolaemia (x 1.5), one developed ezetimibe-induced hypertriglyceridaemia (x 7) and five discontinued for other reasons. CONCLUSION: Ezetimibe is a useful addition to statins in patients with familial hyperlipidaemias but shows a highly variable response profile.

Adolescent↗
PubMed2005

Impaired renal function and atherosclerosis in a Pakistani cohort.

OBJECTIVE: To investigate the relationship of creatinine and calculated glomerular filtration rate (GFR) with coronary arterial disease (CAD) in Pakistani patients. SUBJECTS: Four hundred individuals with chest pain; 200 with angiographic disease matched with 200 without occlusive disease. DESIGN: A prospective case-control study. SETTING: A tertiary referral cardiology unit in Pakistan. RESULTS: Impaired renal function as estimated by calculated GFR was common in this population. Creatinine and glomerular filtration rate, as calculated by the Cockcroft-Gault (CG) and Modification of Diet in Renal Disease (MDRD) formulae, were associated with CAD and atherosclerotic burden in Pakistani patients. Calculation of creatinine clearance, correcting for age, sex and body mass index, showed that clearance was 81 (17-257) mL/min/1.73 m2 in patients with CAD compared with 88 (23-167) mL/min/1.73 m2 in controls with a significant number of patients (18.5 vs. 6.5%; RR = 2.85; p < 0.001) showing significant renal impairment (< 60 mL/min/1.73 m2) by CG and more by the MDRD equation (26 vs. 9%; RR = 2.88; p < 0.001). The unadjusted odds ratios for CAD for a GFR < 60 mL/min/1.73 m2 were 3.66 (1.87-7.16) and 3.29 (1.81-6.01), respectively and, after adjustment for diabetes, smoking, insulin resistance, inflammation and apolipoprotein A1, 1.04 (1.02-1.09) and 1.04 (1.02-1.09), respectively. CONCLUSIONS: Impaired renal function is common in Pakistani patients with coronary arterial disease and is strongly associated with a risk of atherosclerosis independent of insulin resistance.

Adult↗
PubMed2005

Dyslipidaemia and cardiovascular risk in HIV infection.

Cardiovascular disease is increasingly recognised as a consequence of human immunodeficiency virus (HIV) infection in the era of highly active antiretroviral therapy (HAART). Dyslipidaemia is also a feature of HIV infection itself and the antiretroviral drugs from the protease inhibitor classes. Increased rates of atherosclerotic disease and diabetes have been associated with lipodystrophy and now from one of the major causes of morbidity in HIV and acquired immunodeficiency syndrome (AIDS).This review, based on a multi-database keyword search, summarises the lipid changes observed in the course of HIV infection and its treatment, and puts them into the context of other risk factors for cardiac disease, and other causes of cardiovascular disease in HIV.

Anti-Retroviral Agents↗