The effects of lipid-lowering and antioxidant vitamin therapies on flow-mediated vasodilation of the brachial artery in older adults with hypercholesterolemia

Oral L-arginine improves endothelial function in healthy individuals older than 70 years

Ageing is associated with progressive endothelial dysfunction in normal humans. Flow-mediated dilation (FMD) of the brachial artery is impaired in elderly individuals with cardiovascular disease and vascular nitric oxide (NO) bioavailability is reduced. We investigated whether oral L-arginine, the substrate for NO synthesis, can improve impaired FMD in healthy very old people. In a prospective, double-blind, randomized crossover trial, 12 healthy old subjects (age 73.8 6 2.7 years) took L-arginine (8 g p.o. two times daily) or placebo for 14 days each, separated by a wash-out period of 14 days. FMD was determined by high-resolution ultrasound in the brachial artery during reactive hyperaemia. Baseline artery diameter was 3.88 6 0.18 mm. l-Arginine signifi cantly improved FMD (to 5.7 6 1.2%, p, 0.0001), whereas placebo had no effect (-0.25 6 0.7%; n.s.). After L-arginine, plasma levels of L-arginine increased signifi cantly (114.9 6 11.6 versus 57.4 6 5.0 mmol/l), but placebo had no effect. As NO synthesis can be antagonized by its endogenous inhibitor asymmetric dimethyl L-arginine (ADMA), we determined ADMA plasma concentrations, which were elevated at baseline in comparison to healthy middle-aged individuals (3.9 6 0.2 versus 1.0 6 0.1 mmol/l; p, 0.0001). ADMA remained unchanged during treatment, but L-arginine supplementation normalized the L-arginine/ADMA ratio (p, 0.05). We conclude that in healthy very old age endothelial function is impaired and may be improved by oral L-arginine supplementation, probably due to normalization of the L-arginine/ADMA ratio.

The effects of anti-obesity intervention with orlistat and sibutramine on microvascular endothelial function

INTRODUCTION

Obesity is associated with impaired microvascular endothelial function. We aimed to determine the effects of orlistat and sibutramine treatment on microvascular endothelial function, anthropometric and lipid profile, blood pressure (BP), and heart rate (HR).

METHODS

76 subjects were recruited and randomized to receive orlistat 120 mg three times daily or sibutramine 10 mg daily for 9 months. Baseline weight, BMI, BP, HR and lipid profile were taken. Microvascular endothelial function was assessed using laser Doppler fluximetry and iontophoresis process. Maximum change (max), percent change (% change) and peak flux (peak) in perfusion to acetylcholine (ACh) and sodium nitroprusside (SNP) iontophoresis were used to quantify endothelium dependent and independent vasodilatations.

RESULTS

24 subjects in both groups completed the trial. After treatment, weight and BMI were decreased for both groups. AChmax, ACh % change and ACh peak were increased in orlistat-treated group but no difference was observed for sibutramine-treated group. BP and total cholesterol (TC) were reduced for orlistat-treated group. HR was reduced for orlistat-treated group but was increased in sibutramine-treated group.

CONCLUSION

9 months treatment with orlistat significantly improved microvascular endothelial function. This was associated with reductions in weight, BMI, BP, HR, TC and low density lipoprotein cholesterol. No effect was seen in microvascular endothelial function with sibutramine.

Effects of supplementation with the fat-soluble vitamins E and D on fasting flow-mediated vasodilation in adults: a meta-analysis of randomized controlled trials

The effects of fat-soluble vitamin supplementation on cardiovascular disease (CVD) risk are not clear. Therefore, we performed a meta-analysis to quantify effects of fat-soluble vitamin supplements on fasting flow-mediated vasodilation (FMD) of the brachial artery, a validated marker to assess CVD risk. Randomized placebo-controlled trials (RCTs) were identified by a systematic search till July 2014. Seven RCTs studying the effects of vitamin E supplements (range: 300 to 1800 IU per day) and nine RCTs examining the effects of vitamin D supplements, that involved, respectively, 303 and 658 adults, were included. No studies with carotenoid or vitamin K supplements were found. Vitamin E supplementation increased FMD vs. control by 2.42% (95% CI: 0.46% to 4.37%; p = 0.015). No effects of vitamin D supplementation were found (0.15%; 95% CI: −0.21% to 0.51%; p = 0.41). These effects did not depend on subject characteristics, treatment characteristics or technical aspects of the FMD measurement. However, no dose-response relationship was evident for vitamin E, statistical significance depended on one study, while the levels of supplement were far above recommended intakes. The current meta-analysis, therefore, does not provide unambiguous evidence to support the use of fat-soluble vitamin supplements to improve fasting FMD in adults.

Vascular effects and safety of dalcetrapib in patients with or at risk of coronary heart disease: the dal-VESSEL randomized clinical trial

AIMS

High-density lipoprotein cholesterol (HDL-C) is inversely associated with cardiovascular (CV) events and thus an attractive therapeutic target. However, in spite of marked elevations in HDL-C, the first cholesterol transport protein (CETP) inhibitor torcetrapib raised blood pressure (BP), impaired endothelial function, and increased CV mortality and morbidity. Dalcetrapib is a novel molecule acting on CETP with a different chemical structure to torcetrapib. As HDL stimulates nitric oxide (NO), suppresses inflammation, and exerts protective CV effects, we investigated the effects of dalcetrapib on endothelial function, blood pressure, inflammatory markers, and lipids in patients with, or at risk of, coronary heart disease (CHD) in a double-blind randomized placebo-controlled trial (clinicaltrials.gov number NCT00655538).

METHODS AND RESULTS

Patients with target low-density lipoprotein cholesterol (LDL-C) levels received dalcetrapib 600 mg/day or placebo for 36 weeks on top of standard therapy (including statins). The primary outcome measures were the change from baseline of flow-mediated dilatation (%FMD) of the right brachial artery after 5 min of cuff occlusion at 12 weeks and the 24 h ambulatory blood pressure monitoring (ABPM) at week 4. Secondary outcomes included change from baseline in FMD after 36 weeks and the change in ABPM at 12 and 36 weeks, changes in HDL-C, LDL-C, triglycerides, CETP activity, as well as standard safety parameters. Four hundred seventy-six patients were randomized. Baseline FMD was 4.1 ± 2.2 and 4.0 ± 2.4% with placebo or dalcetrapib, respectively and did not change significantly from placebo after 12 and 36 weeks (P = 0.1764 and 0.9515, respectively). After 4, 24, and 36 weeks of treatment with dalcetrapib, CETP activity decreased by 51, 53, and 56% (placebo corrected, all P < 0.0001), while at weeks 4, 12, and 36 HDL-C increased by 25, 27, and 31% (placebo corrected, all P < 0.0001). Low-density lipoprotein cholesterol levels did not change. At baseline, ABPM was 125 ± 12/74 ± 8mmHg in the placebo and 128 ± 11/75 ± 7mmHg in the dalcetrapib group (P = 0.3372 and 0.1248, respectively, placebo-corrected change from baseline) and did not change for up to 36 weeks. Biomarkers of inflammation, oxidative stress, and coagulation did not change during follow-up except for Lp-PLA(2) mass levels which increased by 17% (placebo corrected). Overall 7 patients given dalcetrapib and 8 patients given placebo experienced at least one pre-specified adjudicated event (11 events with dalcetrapib and 12 events with placebo).

CONCLUSION

The dal-VESSEL trial has established the tolerability and safety of CETP-inhibition with dalcetrapib in patients with or at risk of CHD. Dalcetrapib reduced CETP activity and increased HDL-C levels without affecting NO-dependent endothelial function, blood pressure, or markers of inflammation and oxidative stress. The dal-OUTCOMES trial (NCT00658515) will show whether dalcetrapib improves outcomes in spite of a lack of effect on endothelial function.

Impact of Statin Therapy on Central Aortic Pressures and Hemodynamics

Background— Statins reduce the risk of cardiovascular events in people with hypertension. This benefit could arise from a beneficial effect of statins on central aortic pressures and hemodynamics. The Conduit Artery Function Evaluation–Lipid-Lowering Arm (CAFE-LLA) study, an Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT) substudy, investigated this hypothesis in a prospective placebo-controlled study of treated patients with hypertension.

Methods and Results— CAFE-LLA recruited 891 patients randomized to atorvastatin 10 mg/d or placebo from 5 centers in the United Kingdom and Ireland. Radial artery applanation tonometry and pulse-wave analysis were used to derive central aortic pressures and hemodynamic indices at repeated visits over 3.5 years of follow-up. Atorvastatin lowered low-density lipoprotein cholesterol by 32.4 mg/dL (95% confidence interval [CI], 28.6 to 36.3) and total cholesterol by 35.1 mg/dL (95% confidence interval, 30.9 to 39.4) relative to placebo. Time-averaged brachial blood pressure was similar in CAFE-LLA patients randomized to atorvastatin or placebo (change in brachial systolic blood pressure, −0.1 mm Hg [95% CI, −1.8 to 1.6], P =0.9; change in brachial pulse pressure, −0.02 mm Hg [95% CI, −1.6 to 1.6], P =0.9). Atorvastatin did not influence central aortic pressures (change in aortic systolic blood pressure, −0.5 mm Hg [95% CI, −2.3 to 1.2], P =0.5; change in aortic pulse pressure, −0.4 mm Hg [95% CI, −1.9 to 1.0], P =0.6) and had no influence on augmentation index (change in augmentation index, −0.4%; 95% CI, −1.7 to 0.8; P =0.5) or heart rate (change in heart rate, 0.25 bpm; 95% CI, −1.3 to 1.8; P =0.7) compared with placebo. The effect of statin or placebo therapy was not modified by the blood pressure–lowering treatment strategy in the factorial design.

Conclusions— Statin therapy sufficient to significantly reduce cardiovascular events in treated hypertensive patients in ASCOT did not influence central aortic blood pressure or hemodynamics in a large representative cohort of ASCOT patients in CAFE-LLA.

Endothelial function, arterial stiffness and lipid lowering drugs

The endothelium is a dynamic organ that plays a pivotal role in cardiovascular homeostasis. Alteration in endothelial function precedes the development of atherosclerosis and contributes to its initiation, perpetuation and clinical manifestations. It has been suggested that the assessment of endothelial function could represent a barometer of vascular health that could be used to gauge cardiovascular risk. This review summarises the various methods used to assess endothelium-dependent vasodilatation and their potential prognostic implications. In addition, the techniques used to evaluate arterial stiffness are discussed. The latter is to some extent controlled by the endothelium and has been the subject of considerable research in recent years. This paper also discusses the effects of lipid lowering treatment on both endothelial function and arterial stiffness.

Cautions in the use of biomarkers of oxidative damage; the vascular and antioxidant effects of dark soy sauce in humans

Dark soy sauce (DSS) is a powerful antioxidant in vitro. We investigated whether this effect could occur in vivo and improve vascular function. Healthy human subjects were given DSS or placebo meals in a randomized, crossover study. Blood and urine were sampled before and 1, 2, 3, and 4h after the meal for F(2)-isoprostanes (total, free, and esterified) and 8OHdG measurements. Blood pressure, vascular augmentation index (AIx), and heart rate (HR) were also measured. Plasma total F(2)-isoprostanes significantly decreased 3h after placebo and the decrease was greater for DSS. Plasma free and esterified F(2)-isoprostanes were also significantly decreased after DSS. Both placebo and DSS meals increased urinary F(2)-isoprostanes at 1h but not thereafter, and lowered urinary 8OHdG levels, DBP and AIx, and increased HR. We conclude that DSS decreases lipid peroxidation in vivo. However, oxidative damage biomarkers changed after the placebo meal, a phenomenon to consider when designing interventional studies.

Homocysteine Lowering with Folic Acid and Vitamin B Supplements

Cardiovascular disease (CVD) is the leading cause of death in older men and women and contributes significantly to morbidity in later life. Folic acid and other vitamin B deficiencies and elevated total plasma homocysteine levels are associated with increased cardiovascular risk in geriatric patients, but recent studies have questioned the importance of these risk factors in older people. Data on the effects of homocysteine-lowering therapy (e.g. folic acid and vitamin B supplements) on surrogate CVD endpoints, such as atherosclerotic progression, endothelial function, inflammation and hypercoagulation, are conflicting. Findings from randomised clinical trials using clinical CVD outcomes show that folic acid and vitamin B supplements may not provide cardiovascular protection. Furthermore, these findings raise questions about whether the combination of folic acid and B vitamins may actually be harmful. Other large randomised clinical trials are underway to help clarify the role of folic acid and vitamin B supplements in CVD prevention in older people. Data to date do not support use of homocysteine-lowering therapies in either middle-aged or older adults.

Clinical impact of vasomotor function assessment and the role of ACE-inhibitors and statins

Impaired endothelial function is recognised as one of the earliest events of atherogenesis. Endothelium-dependent vasomotion has been the principal method to assess endothelial function. In this article, we will discuss the clinical value of the different techniques to evaluate endothelium-dependent vasomotion. To date, there seems not to be a simple and reliably endothelial function test to identify asymptomatic subjects at increased risk for cardiovascular disease in clinical practice. Recent studies indicate that pharmacological interventions, in particular with ACE-inhibitors and statins, might improve endothelial function. However, there is no solid evidence that improvement of endothelial function is a necessity for the observed reduction in cardiovascular events by these compounds. Overall, at this moment, there is no place in clinical practice for the use of endothelial function as a method for risk assessment or target of pharmacological interventions.

Effects of combined administration of low dose atorvastatin and vitamin E on inflammatory markers and endothelial function in patients with heart failure

BACKGROUND

Heart failure has been associated with impaired endothelial function, increased inflammatory process and elevated oxidative stress status. Both statins and vitamin E separately improve endothelial function in patients with hypercholesterolemia and/or advanced atherosclerosis.

AIM

To evaluate the effect of atorvastatin alone or in combination with vitamin E on endothelial function and serum levels of interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-alpha) and vascular cells adhesion molecule (sVCAM-1) in patients with ischemic heart failure.

METHODS

Thirty-eight male patients with ischemic cardiomyopathy were randomly divided into three groups and received either atorvastatin 10 mg/day (n = 14), a combination of atorvastatin 10 mg/day plus vitamin E 400 IU/day (n = 12), or no statin or antioxidant treatment (n=12, controls) for 4 weeks. Forearm blood flow (FBF) was measured using venous occlusion strain-gauge plethysmography. Forearm vasodilatory response to reactive hyperemia (RH%) or to nitrate (NTG%) was defined as the percent change of FBF from rest to the maximum flow during reactive hyperemia or after nitrate administration, respectively.

RESULTS

RH% was significantly improved in both the atorvastatin-treated (p < 0.01) and atorvastatin plus vitamin E groups (p < 0.05), but the increase was significantly higher in the atorvastatin-treated group (p < 0.05). Serum levels of IL-6, TNF-alpha and sVCAM-1 were decreased in the atorvastatin-treated group (p < 0.05 for all), but remained unaffected in the other two groups (p = NS for all).

CONCLUSIONS

Low dose atorvastatin treatment improves endothelial function and reduces the expression of proinflammatory cytokines and adhesion molecules in patients with ischemic heart failure, an effect partly depressed by vitamin E.

Evaluating Cardiovascular Pathophysiology and Anatomy in Atherosclerosis

The process of atherosclerosis begins with endothelial dysfunction from impaired bioavailability of NO and progresses through multiple stages of plaque development. Impaired endothelial function decreases NO and increases oxidized macromolecules such as low-density lipoprotein cholesterol. Oxidized low-density lipoprotein cholesterol accumulates in subendothelial space, forming plaques that may eventually compromise the lumen. Acute coronary events result from plaque rupture and consequent thrombus formation and abrupt occlusion of the vessel lumen. New diagnostic methods such as flow-mediated dilation of the brachial artery can detect endothelial dysfunction, and intravascular ultrasound can detect early plaque formation in the arterial wall. These techniques may provide a means to identify patients at risk for adverse cardiovascular outcomes, thereby enabling physicians to potentially prevent adverse events by early initiation of lipid-lowering therapy.

Effect of Intensive Lipid Lowering, With or Without Antioxidant Vitamins, Compared With Moderate Lipid Lowering on Myocardial Ischemia in Patients With Stable Coronary Artery Disease

Background— Lipid lowering with statins prevents adverse cardiac events. Both lipid-lowering and antioxidant therapies may favorably affect vasomotor function and thereby improve ischemia.

Methods and Results— In a randomized, double-blind, placebo-controlled trial, 300 patients with stable coronary disease, a positive exercise treadmill test, 48-hour ambulatory ECG with ≥1 episode of ischemia, and fasting total cholesterol of 180 to 250 mg/dL were assigned to 1-year treatment with intensive atorvastatin to reduce LDL to <80 mg/dL (n=96), intensive atorvastatin to reduce LDL to <80 mg/dL plus antioxidant vitamins C (1000 mg/d) and E (800 mg/d) (n=101), or diet and low-dose lovastatin, if needed, to reduce LDL to <130 mg/dL (n=103; control group). Ischemia end points, including ambulatory ECG monitoring and exercise treadmill testing, and endothelial assessment using brachial artery flow-mediated dilation were obtained at baseline and at 6 and 12 months. Baseline characteristics were similar in all groups. LDL decreased from ≈153 mg/dL at baseline in the 2 atorvastatin groups to ≈83 mg/dL at 12 months (each P <0.0001) and from 147 to 120 mg/dL in the control group ( P <0.0001). During ambulatory ECG monitoring, mean number of ischemic episodes per 48 hours decreased 31% to 61% in each group (each P <0.001; P =0.15 across groups), without a change in daily heart rate activity. Mean duration of ischemia for 48 hours decreased 26% to 62% in each group (each P <0.001; P =0.06 across groups). Mean exercise duration to 1-mm ST-segment depression significantly increased in each group, but total exercise duration and mean sum of maximum ST depression were unchanged. Angina frequency decreased in each group. There was no incremental effect of supplemental vitamins C and E on any ischemia outcome. Flow-mediated dilation studies indicated no meaningful changes.

Conclusions— Intensive lipid lowering with atorvastatin to an LDL level of 80 mg/dL, with or without antioxidant vitamins, does not provide any further benefits in ambulatory ischemia, exercise time to onset of ischemia, and angina frequency than moderate lipid lowering with diet and low-dose lovastatin to an LDL level of <120 mg/dL.

Hormone therapy and antioxidant vitamins do not improve endothelial vasodilator function in postmenopausal women with established coronary artery disease: a substudy of the Women's Angiographic Vitamin and Estrogen (WAVE) trial

We measured flow-mediated dilation (FMD) by high-resolution brachial ultrasound in 61 women who participated in the Women's Angiographic Vitamin and Estrogen (WAVE) trial, a randomized controlled trial. There were no significant differences in the baseline demographics of women receiving hormone therapy (0.625 mg/day of conjugated equine estrogen plus 2.5mg of medroxyprogesterone acetate for women who had not had a hysterectomy) or placebo; or vitamins (400 IU of Vitamin E and 500 mg of Vitamin C twice daily) or placebo. Baseline FMD was impaired in all subjects (3.3+/-7.6%). Neither hormone therapy (4.1+/-5.2% at baseline, 4.2+/-5.0% at 3 months, and 4.1+/-6.5% at 34 months) nor antioxidant vitamins (3.0+/-8.3% at baseline; 3.5+/-4.6% at 3 months; 3.1+/-7.6% at 34 months) improved FMD (all p-values=NS). Endothelium-independent vasodilation, induced by nitroglycerin (NTG) was similar at baseline and was not affected by either therapy. In univariate and multivariate analysis, neither hormone therapy nor antioxidant vitamins were associated with FMD. Women with established coronary artery disease have impaired flow-mediated vasodilation of the brachial artery that does not improve after 3 months or up to 34 months of treatment with postmenopausal hormone therapy or antioxidant vitamins.

Assessment of flow-mediated vasodilatation (FMD) of the brachial artery: effects of technical aspects of the FMD measurement on the FMD response

AIMS

The ability to assess endothelial function non-invasively with B-mode ultrasound has lead to its widespread application in a variety of studies. However, the absolute values obtained using this approach vary considerably across studies. We studied whether technical aspects of the methodology can explain the wide variety in absolute values across studies.

METHODS AND RESULTS

A literature search was performed to identify published reports on flow-mediated vasodilatation (FMD) of the brachial artery published between 1992 and 2001. Information on type of equipment (wall track/B-mode), location of the measurement (antecubital fossa/upper arm), occlusion site (lower/upper arm), occlusion duration (min), and occlusion pressure was extracted. Patient characteristics were also extracted. For the healthy populations, mean FMD varied from 0.20 to 19.2%; for the coronary heart disease (CHD) patients FMD varied from -1.3 to 14%; for subjects with diabetes mellitus FMD varied from 0.75 to 12%. Compared with occlusion at the upper arm, lower arm occlusion was related to decreased FMD (mean difference in FMD -2.47%; 95% CI 0.55-4.39). An occlusion duration of > or =4.5 min was related to an increased FMD compared with an occlusion time of < or =4 min (mean difference 1.30%; 95% CI 0.35-2.46). These findings were adjusted for other technical aspects of the methodology and for differences in risk factors between populations.

CONCLUSION

Mean FMD differs widely between studies. There is a great overlap between populations (healthy, CHD, diabetics). Our findings suggest that the technical aspects of the measurements, the location, and the duration of the occlusion may explain some of these differences, whereas type of equipment, location of the measurement, and occlusion pressure do not.

Effects of statins on vascular structure and function: a systematic review

PURPOSE

Statins reduce cardiovascular events by more than can be explained by their effects on lipids. We conducted a systematic review of how statins affect vascular structure and function, differences among statins, and correlations between the effects of statins on vascular outcomes and either lipid levels or cardiovascular outcomes.

METHODS

We primarily searched MEDLINE (1980 to March 2004) to identify all studies with at least 10 subjects that reported the effects of currently available statins on coronary artery stenosis, carotid intima-media thickness, and endothelial function (excluding studies of drug combinations and subjects with organ transplants). Meta-analyses were performed when feasible.

RESULTS

Statins decrease the progression and increase the regression of coronary artery lesions and luminal narrowing. Compared with placebo, statins decrease the likelihood of coronary artery restenosis (summary risk ratio = 0.85; 95% confidence interval: 0.77 to 0.95). Statins appear to slow the progression of carotid artery intima-media thickness. Although the effect of statins on coronary endothelial function is uncertain, statins appear to improve peripheral endothelial function. There is no conclusive evidence to suggest that individual statins differ in their effects on these outcomes. Studies generally found weak or no correlation between the effects of statins on vascular outcomes and lipid levels. No study showed a correlation between vascular effect and clinical outcome.

CONCLUSION

Statins slow the progression of, and may reverse, atherosclerosis. The magnitude of these effects, however, is small compared with the effects of statins on cardiovascular events. Statins also improve measures of vascular function, which may contribute to their clinical benefits. There is insufficient evidence to suggest that individual statins differ in their vascular effects.

Assessing endothelial function as a risk factor for cardiovascular disease

The vascular endothelium plays a key role in the prevention of atherosclerosis. Endothelial dysfunction is an antecedent of clinical cardiovascular disease and can be viewed as the final pathway between coronary risk factors and the development of atherosclerosis. The development of a noninvasive method of assessing endothelial health (ie, measurement of flow- mediated dilation of the brachial artery) has enabled investigators to evaluate the effects of dietary patterns on vascular function. Emerging evidence indicates that dietary fats may acutely impair endothelial function, but this effect is dependent on the type of fat and on the other nutrients consumed. Although inconclusive, studies in cohorts of modest size suggest that antioxidants, L-arginine, and folic acid may modulate endothelial function. Additional research is needed to define the impact of complex, long-term dietary patterns on the vascular endothelium.

Effects of multivitamins and low-dose folic acid supplements on flow-mediated vasodilation and plasma homocysteine levels in older adults

BACKGROUND

Hyperhomocysteinemia is associated with aging, endothelial dysfunction, and increased risk of coronary heart disease in older adults; however, the effects of homocysteine-lowering therapy on vascular reactivity in older persons are unknown. The objective of this study was to determine the effects of multivitamins (MV) and folic acid (FA) supplements on flow-mediated vasodilation (FMD) in older adults.

METHODS

Individuals > or =70 years old with homocysteine levels > or =10 micromol/L were recruited for this 40-week, prospective, single-blinded study. All subjects were treated sequentially, with each of the following daily therapies for 10 weeks: (1) placebo, (2) MV (400 microg FA, 6 mg vitamin B6, 25 microg vitamin B12), (3) placebo, then (4) MV + FA (total FA, 1400 microg). FMD, folate intake, and laboratory values were measured at each visit. Investigators were blinded to subject treatment phase when measuring vessel diameters and calculating FMD.

RESULTS

Twenty subjects (mean +/- SEM age, 78.0 +/- 1.2 [range, 70 to 88] years, 9 women) completed the MV and 17 completed the MV + FA interventions. FMD was impaired at baseline (2.0% +/- 1.2%). During the 40-week study, homocysteine levels decreased by 1.4 +/- 0.9 micromol/L (p(trend) = 0.034) from a baseline of 12.8 +/- 0.6 micromol/L; however, FMD did not change significantly (p(trend) = 0.874). FMD did not improve after therapy with MV alone (3.0% +/- 0.9% [week 10] vs 2.4% +/- 1.1% [week 20], P =.716) or with MV + FA (2.6% +/- 0.9% [week 30] vs 1.9% +/- 0.7% [week 40], P =.484).

CONCLUSIONS

At doses commonly prescribed in clinical practice, MV and FA supplements did not improve FMD in older adults with hyperhomocysteinemia.

Brachial artery vasomotor function is inversely associated with 24-h ambulatory blood pressure

BACKGROUND

Impaired endothelial function has been reported in hypertensive individuals. The extent to which such changes reflect the co-existence of other cardiovascular disease risk factors rather than an independent association with blood pressure remains uncertain.

OBJECTIVE

To assess the relationship between brachial artery vasomotor function and ambulatory blood pressure in hypertensive individuals and normotensive controls.

METHODS

We assessed 24-h ambulatory blood pressure and brachial artery endothelial and smooth muscle function in 155 patients with hypertension and 40 normotensive controls. The vasomotor functions were determined by ultrasonographic assessment of vasodilator responses to flow and sublingual glyceryl trinitrate, respectively. Patients with hypertension were categorized as either treated (n = 85) or untreated (n = 70), and further subdivided on the basis of either no or at least one other cardiovascular risk factor. These included hyperlipidaemia, smoking, diabetes or a previous coronary or cerebrovascular event.

RESULTS

Age- and sex-adjusted flow-mediated and glyceryl trinitrate-mediated responses were not significantly different in hypertensive individuals with respect to treatment status or the presence of risk factors when compared with controls. However, when data from all 195 study participants were pooled, 24-h ambulatory systolic blood pressure was inversely related to flow-mediated response (P = 0.002), and both systolic and diastolic blood pressure were inversely related to glyceryl trinitrate response (P < 0.001 and P = 0.009, respectively). Observed relationships were largely unaltered after further adjustment for body mass index, antihypertensive treatment or the presence of other risk factors.

CONCLUSIONS

The finding of a direct and inverse relationship between the level of ambulatory blood pressure and flow-mediated and glyceryl trinitrate responses is consistent with a direct influence of blood pressure on conduit vessel vascular function.

Health-related quality of life and long-term therapy with pravastatin and tocopherol (vitamin E) in older adults

INTRODUCTION

Concerns about the effects of HMG-CoA reductase inhibitors ('statins') on health-related quality of life may contribute to their underuse in older adults with and at risk for cardiovascular disease. These concerns also may prevent clinicians from enrolling older patients in clinical trials assessing the efficacy of statins as a preventive therapy for Alzheimer's disease.

OBJECTIVE

To determine the effects of pravastatin and tocopherol (vitamin E), alone and in combination, on health-related quality of life in older adults.

STUDY DESIGN

Double-blind, randomised, placebo-controlled, crossover study.

PARTICIPANTS

Forty-one community-dwelling men and women aged > or = 70 years with low-density lipoprotein-cholesterol (LDL-C) > or = 3.62 mmol/L (140 mg/dl) participated.

METHODS

Subjects received pravastatin for 6 months then pravastatin plus tocopherol for an additional 6 months (group 1), or tocopherol for 6 months then pravastatin plus tocopherol for an additional 6 months (group 2). Dosages were pravastatin 20 mg daily and tocopherol 400 IU daily.

MAIN OUTCOME MEASURES

The following health-related quality-of-life measures were assessed at baseline, after 6 months and after 1 year: health perception, depression, physical function, cognitive function and sleep behaviour. In addition, data on adverse effects and laboratory abnormalities were obtained.

RESULTS

Pravastatin reduced levels of total cholesterol (-21%, p < 0.001) and LDL-C (-29%, p < 0.001). Health-related quality-of-life scores, physical adverse effects, muscle enzyme levels and liver function tests did not change after 12 months of therapy with pravastatin, tocopherol or their combination.

CONCLUSION

Both pravastatin and tocopherol have a good safety profile, are well tolerated and do not adversely affect health-related quality of life in older patients with hypercholesterolaemia. Given the significant beneficial cardiovascular effects of statin therapy in older adults and the potential role of statins in prevention of Alzheimer's disease, concerns about adverse effects on quality of life should not deter use of these medications in this population.

[The statins: new properties]]

The comparison of major statin trials with trials using either cholestyramine or ileal bypass has suggested that the reduction in coronary heart disease events for those patients receiving statin therapy largely result from their low density lipoprotein (LDL)-cholesterol lowering action. LDL-cholesterol lowering has several physiological consequences, including plaque stabilisation with a decrease in the inflammatory process, slowing of plaque progression, and improvement of endothelial function, as evidenced by the measurement of endothelial-dependent vasorelaxation in response to hyperhaemia or acetylcholine infusion. Statins lower C-reactive protein without any consistent effect on the other inflammation acute phase proteins. The cause and consequences of this effect are still debated. In order to explain why some statins can prevent coronary events within a few months, a direct effect of this therapy on thrombosis has also been advocated; however, the evaluation of statin antithrombotic effects in humans has produced conflicting results. By inhibiting L-mevalonic acid synthesis, statins also prevent the farnelysation of small-GTP binding proteins such as Rho and Ras. In vitro, and in animal models, the inhibition of Rho with statins results in a decrease in endothelial nitric oxide production, an inhibition of leucocyte adhesion on endothelium, decrease in PPAR alpha activation and high density lipoprotein (HDL) production by the hepatocyte, decrease in Ca2+ stores in vascular smooth cells, and a stimulation of vascular smooth muscle cell apoptosis. However, most of these effects were obtained with high statin concentrations. Further evidence is needed before a full assessment of the clinical importance of isoprenylation blockage with therapeutic concentrations of statins in humans can be made.

Pravastatin

Pravastatin (Pravachol) is a competitive, reversible HMG-CoA reductase inhibitor that lowers serum cholesterol levels by inhibiting de novo cholesterol synthesis and has antiatherogenic effects that appear to be partially independent of its lipid-lowering effects. Pravastatin 10-40 mg/day produced significant reductions (vs baseline or placebo) in serum total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) levels in elderly patients (aged >or=60 or >or= 65 years) with hypercholesterolaemia or normal cholesterol levels. Serum triglyceride and high-density lipoprotein cholesterol levels also improved in some studies, but not in others. Coadministration of cholestyramine, another lipid-lowering agent, further enhanced the lipid-lowering effects of pravastatin in elderly patients. Data from the large, long-term (3-6 years) PROspective Study Of Pravastatin in the Elderly at Risk (PROSPER), Cholesterol And Recurrent Events trial (CARE) and Long term Intervention with Pravastatin in Ischaemic Disease (LIPID) trials demonstrated that pravastatin 40 mg/day reduces coronary events in elderly patients with hypercholesterolaemia or normal cholesterol levels, with or at high risk of developing coronary heart disease (CHD). In these trials, the incidence of death from CHD or the combined endpoint of death from CHD or nonfatal myocardial infarction was significantly lower in pravastatin than in placebo recipients. Pravastatin is well tolerated in the elderly, and adverse effects considered related to therapy are minimal. The most commonly occurring adverse events included gastrointestinal events, renal or genital system events, respiratory disorders, headaches and musculoskeletal pain.

CONCLUSION

Pravastatin effectively lowers serum TC and LDL-C levels and, as demonstrated in major clinical outcome trials, reduces coronary events in elderly patients with hypercholesterolaemia or normal cholesterol levels. Pravastatin is well tolerated and as such should be considered a first-line agents for primary or secondary prevention in older individuals with evident CHD or multiple risk factors for CHD.