RESUMEN
BACKGROUND: High triglyceride levels are associated with increased cardiovascular risk, but whether reductions in these levels would lower the incidence of cardiovascular events is uncertain. Pemafibrate, a selective peroxisome proliferator-activated receptor α modulator, reduces triglyceride levels and improves other lipid levels. METHODS: In a multinational, double-blind, randomized, controlled trial, we assigned patients with type 2 diabetes, mild-to-moderate hypertriglyceridemia (triglyceride level, 200 to 499 mg per deciliter), and high-density lipoprotein (HDL) cholesterol levels of 40 mg per deciliter or lower to receive pemafibrate (0.2-mg tablets twice daily) or matching placebo. Eligible patients were receiving guideline-directed lipid-lowering therapy or could not receive statin therapy without adverse effects and had low-density lipoprotein (LDL) cholesterol levels of 100 mg per deciliter or lower. The primary efficacy end point was a composite of nonfatal myocardial infarction, ischemic stroke, coronary revascularization, or death from cardiovascular causes. RESULTS: Among 10,497 patients (66.9% with previous cardiovascular disease), the median baseline fasting triglyceride level was 271 mg per deciliter, HDL cholesterol level 33 mg per deciliter, and LDL cholesterol level 78 mg per deciliter. The median follow-up was 3.4 years. As compared with placebo, the effects of pemafibrate on lipid levels at 4 months were -26.2% for triglycerides, -25.8% for very-low-density lipoprotein (VLDL) cholesterol, -25.6% for remnant cholesterol (cholesterol transported in triglyceride-rich lipoproteins after lipolysis and lipoprotein remodeling), -27.6% for apolipoprotein C-III, and 4.8% for apolipoprotein B. A primary end-point event occurred in 572 patients in the pemafibrate group and in 560 of those in the placebo group (hazard ratio, 1.03; 95% confidence interval, 0.91 to 1.15), with no apparent effect modification in any prespecified subgroup. The overall incidence of serious adverse events did not differ significantly between the groups, but pemafibrate was associated with a higher incidence of adverse renal events and venous thromboembolism and a lower incidence of nonalcoholic fatty liver disease. CONCLUSIONS: Among patients with type 2 diabetes, mild-to-moderate hypertriglyceridemia, and low HDL and LDL cholesterol levels, the incidence of cardiovascular events was not lower among those who received pemafibrate than among those who received placebo, although pemafibrate lowered triglyceride, VLDL cholesterol, remnant cholesterol, and apolipoprotein C-III levels. (Funded by the Kowa Research Institute; PROMINENT ClinicalTrials.gov number, NCT03071692.).
Asunto(s)
Enfermedades Cardiovasculares , Diabetes Mellitus Tipo 2 , Hipertrigliceridemia , Hipolipemiantes , PPAR alfa , Humanos , Apolipoproteína C-III/sangre , Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/etiología , Colesterol/sangre , LDL-Colesterol/sangre , Diabetes Mellitus Tipo 2/complicaciones , Método Doble Ciego , Factores de Riesgo de Enfermedad Cardiaca , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Hiperlipidemias/sangre , Hiperlipidemias/tratamiento farmacológico , Hipertrigliceridemia/sangre , Hipertrigliceridemia/complicaciones , Hipertrigliceridemia/tratamiento farmacológico , Factores de Riesgo , Triglicéridos/sangre , Hipolipemiantes/uso terapéutico , PPAR alfa/agonistas , HDL-Colesterol/sangreRESUMEN
BACKGROUND: Assessment for risks associated with acute stable COVID-19 is important to optimize clinical trial enrollment and target patients for scarce therapeutics. To assess whether healthcare system engagement location is an independent predictor of outcomes we performed a secondary analysis of the ACTIV-4B Outpatient Thrombosis Prevention trial. METHODS: A secondary analysis of the ACTIV-4B trial that was conducted at 52 US sites between September 2020 and August 2021. Participants were enrolled through acute unscheduled episodic care (AUEC) enrollment location (emergency department, or urgent care clinic visit) compared to minimal contact (MC) enrollment (electronic contact from test center lists of positive patients).We report the primary composite outcome of cardiopulmonary hospitalizations, symptomatic venous thromboembolism, myocardial infarction, stroke, transient ischemic attack, systemic arterial thromboembolism, or death among stable outpatients stratified by enrollment setting, AUEC versus MC. A propensity score for AUEC enrollment was created, and Cox proportional hazards regression with inverse probability weighting (IPW) was used to compare the primary outcome by enrollment location. RESULTS: Among the 657 ACTIV-4B patients randomized, 533 (81.1%) with known enrollment setting data were included in this analysis, 227 from AUEC settings and 306 from MC settings. In a multivariate logistic regression model, time from COVID test, age, Black race, Hispanic ethnicity, and body mass index were associated with AUEC enrollment. Irrespective of trial treatment allocation, patients enrolled at an AUEC setting were 10-times more likely to suffer from the adjudicated primary outcome, 7.9% vs. 0.7%; p < 0.001, compared with patients enrolled at a MC setting. Upon Cox regression analysis adjustment patients enrolled at an AUEC setting remained at significant risk of the primary composite outcome, HR 3.40 (95% CI 1.46, 7.94). CONCLUSIONS: Patients with clinically stable COVID-19 presenting to an AUEC enrollment setting represent a population at increased risk of arterial and venous thrombosis complications, hospitalization for cardiopulmonary events, or death, when adjusted for other risk factors, compared with patients enrolled at a MC setting. Future outpatient therapeutic trials and clinical therapeutic delivery programs of clinically stable COVID-19 patients may focus on inclusion of higher-risk patient populations from AUEC engagement locations. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04498273.
Asunto(s)
COVID-19 , Accidente Cerebrovascular , Trombosis de la Vena , Humanos , Anticoagulantes/uso terapéutico , Trombosis de la Vena/tratamiento farmacológico , Accidente Cerebrovascular/epidemiología , Accidente Cerebrovascular/prevención & control , HospitalizaciónRESUMEN
BACKGROUND: Inflammation is causally related to atherothrombosis. Treatment with canakinumab, a monoclonal antibody that inhibits inflammation by neutralizing interleukin-1ß, resulted in a lower rate of cardiovascular events than placebo in a previous randomized trial. We sought to determine whether an alternative approach to inflammation inhibition with low-dose methotrexate might provide similar benefit. METHODS: We conducted a randomized, double-blind trial of low-dose methotrexate (at a target dose of 15 to 20 mg weekly) or matching placebo in 4786 patients with previous myocardial infarction or multivessel coronary disease who additionally had either type 2 diabetes or the metabolic syndrome. All participants received 1 mg of folate daily. The primary end point at the onset of the trial was a composite of nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. Near the conclusion of the trial, but before unblinding, hospitalization for unstable angina that led to urgent revascularization was added to the primary end point. RESULTS: The trial was stopped after a median follow-up of 2.3 years. Methotrexate did not result in lower interleukin-1ß, interleukin-6, or C-reactive protein levels than placebo. The final primary end point occurred in 201 patients in the methotrexate group and in 207 in the placebo group (incidence rate, 4.13 vs. 4.31 per 100 person-years; hazard ratio, 0.96; 95% confidence interval [CI], 0.79 to 1.16). The original primary end point occurred in 170 patients in the methotrexate group and in 167 in the placebo group (incidence rate, 3.46 vs. 3.43 per 100 person-years; hazard ratio, 1.01; 95% CI, 0.82 to 1.25). Methotrexate was associated with elevations in liver-enzyme levels, reductions in leukocyte counts and hematocrit levels, and a higher incidence of non-basal-cell skin cancers than placebo. CONCLUSIONS: Among patients with stable atherosclerosis, low-dose methotrexate did not reduce levels of interleukin-1ß, interleukin-6, or C-reactive protein and did not result in fewer cardiovascular events than placebo. (Funded by the National Heart, Lung, and Blood Institute; CIRT ClinicalTrials.gov number, NCT01594333.).
Asunto(s)
Aterosclerosis/prevención & control , Enfermedades Cardiovasculares/prevención & control , Enfermedad de la Arteria Coronaria/tratamiento farmacológico , Inmunosupresores/administración & dosificación , Metotrexato/administración & dosificación , Infarto del Miocardio/tratamiento farmacológico , Anciano , Proteína C-Reactiva/análisis , Enfermedades Cardiovasculares/mortalidad , Intervalos de Confianza , Enfermedad de la Arteria Coronaria/complicaciones , Diabetes Mellitus Tipo 2/complicaciones , Método Doble Ciego , Femenino , Estudios de Seguimiento , Humanos , Inmunosupresores/efectos adversos , Interleucina-1beta/sangre , Interleucina-6/sangre , Masculino , Síndrome Metabólico/complicaciones , Metotrexato/efectos adversos , Persona de Mediana Edad , Infarto del Miocardio/complicaciones , Modelos de Riesgos Proporcionales , Estadísticas no Paramétricas , Accidente Cerebrovascular/etiología , Accidente Cerebrovascular/prevención & control , Transaminasas/sangreRESUMEN
Importance: Acutely ill inpatients with COVID-19 typically receive antithrombotic therapy, although the risks and benefits of this intervention among outpatients with COVID-19 have not been established. Objective: To assess whether anticoagulant or antiplatelet therapy can safely reduce major adverse cardiopulmonary outcomes among symptomatic but clinically stable outpatients with COVID-19. Design, Setting, and Participants: The ACTIV-4B Outpatient Thrombosis Prevention Trial was designed as a minimal-contact, adaptive, randomized, double-blind, placebo-controlled trial to compare anticoagulant and antiplatelet therapy among 7000 symptomatic but clinically stable outpatients with COVID-19. The trial was conducted at 52 US sites between September 2020 and June 2021; final follow-up was August 5, 2021. Prior to initiating treatment, participants were required to have platelet count greater than 100â¯000/mm3 and estimated glomerular filtration rate greater than 30 mL/min/1.73 m2. Interventions: Random allocation in a 1:1:1:1 ratio to aspirin (81 mg orally once daily; n = 164), prophylactic-dose apixaban (2.5 mg orally twice daily; n = 165), therapeutic-dose apixaban (5 mg orally twice daily; n = 164), or placebo (n = 164) for 45 days. Main Outcomes and Measures: The primary end point was a composite of all-cause mortality, symptomatic venous or arterial thromboembolism, myocardial infarction, stroke, or hospitalization for cardiovascular or pulmonary cause. The primary analyses for efficacy and bleeding events were limited to participants who took at least 1 dose of trial medication. Results: On June 18, 2021, the trial data and safety monitoring board recommended early termination because of lower than anticipated event rates; at that time, 657 symptomatic outpatients with COVID-19 had been randomized (median age, 54 years [IQR, 46-59]; 59% women). The median times from diagnosis to randomization and from randomization to initiation of study treatment were 7 days and 3 days, respectively. Twenty-two randomized participants (3.3%) were hospitalized for COVID-19 prior to initiating treatment. Among the 558 patients who initiated treatment, the adjudicated primary composite end point occurred in 1 patient (0.7%) in the aspirin group, 1 patient (0.7%) in the 2.5-mg apixaban group, 2 patients (1.4%) in the 5-mg apixaban group, and 1 patient (0.7%) in the placebo group. The risk differences compared with placebo for the primary end point were 0.0% (95% CI not calculable) in the aspirin group, 0.7% (95% CI, -2.1% to 4.1%) in the 2.5-mg apixaban group, and 1.4% (95% CI, -1.5% to 5.0%) in the 5-mg apixaban group. Risk differences compared with placebo for bleeding events were 2.0% (95% CI, -2.7% to 6.8%), 4.5% (95% CI, -0.7% to 10.2%), and 6.9% (95% CI, 1.4% to 12.9%) among participants who initiated therapy in the aspirin, prophylactic apixaban, and therapeutic apixaban groups, respectively, although none were major. Findings inclusive of all randomized patients were similar. Conclusions and Relevance: Among symptomatic clinically stable outpatients with COVID-19, treatment with aspirin or apixaban compared with placebo did not reduce the rate of a composite clinical outcome. However, the study was terminated after enrollment of 9% of participants because of an event rate lower than anticipated. Trial Registration: ClinicalTrials.gov Identifier: NCT04498273.
Asunto(s)
Aspirina/uso terapéutico , Tratamiento Farmacológico de COVID-19 , Inhibidores del Factor Xa/uso terapéutico , Inhibidores de Agregación Plaquetaria/uso terapéutico , Pirazoles/uso terapéutico , Piridonas/uso terapéutico , Trombosis/prevención & control , Adulto , Aspirina/efectos adversos , COVID-19/complicaciones , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Terminación Anticipada de los Ensayos Clínicos , Inhibidores del Factor Xa/administración & dosificación , Inhibidores del Factor Xa/efectos adversos , Femenino , Hemorragia/inducido químicamente , Hospitalización , Humanos , Masculino , Persona de Mediana Edad , Inhibidores de Agregación Plaquetaria/efectos adversos , Pirazoles/administración & dosificación , Pirazoles/efectos adversos , Piridonas/administración & dosificación , Piridonas/efectos adversosRESUMEN
BACKGROUND: Inflammation plays a fundamental role in atherothrombosis. Yet, whether direct inhibition of inflammation will reduce the occurrence of adverse cardiovascular outcomes is not known. DESIGN: The Cardiovascular Inflammation Reduction Trial (CIRT) (ClinicalTrials.govNCT01594333) will randomly allocate 7,000 patients with prior myocardial infarction (MI) and either type 2 diabetes or the metabolic syndrome to low-dose methotrexate (target dose 15-20 mg/wk) or placebo over an average follow-up period of 3 to 5 years. Low-dose methotrexate is a commonly used anti-inflammatory regimen for the treatment of rheumatoid arthritis and lacks significant effects on lipid levels, blood pressure, or platelet function. Both observational and mechanistic studies suggest that low-dose methotrexate has clinically relevant antiatherothrombotic effects. The CIRT primary end point is a composite of nonfatal MI, nonfatal stroke, and cardiovascular death. Secondary end points are all-cause mortality, coronary revascularization plus the primary end point, hospitalization for congestive heart failure plus the primary end point, all-cause mortality plus coronary revascularization plus congestive heart failure plus the primary end point, incident type 2 diabetes, and net clinical benefit or harm. CIRT will use standardized central methodology designed to ensure consistent performance of all dose adjustments and safety interventions at each clinical site in a manner that protects the blinding to treatment but maintains safety for enrolled participants. SUMMARY: CIRT aims to test the inflammatory hypothesis of atherothrombosis in patients with prior MI and either type 2 diabetes or metabolic syndrome, conditions associated with persistent inflammation. If low-dose methotrexate reduces cardiovascular events, CIRT would provide a novel therapeutic approach for the secondary prevention of heart attack, stroke, and cardiovascular death.
Asunto(s)
Antiinflamatorios/uso terapéutico , Diabetes Mellitus Tipo 2/complicaciones , Inflamación/tratamiento farmacológico , Síndrome Metabólico/complicaciones , Metotrexato/uso terapéutico , Infarto del Miocardio/tratamiento farmacológico , Algoritmos , Antiinflamatorios/administración & dosificación , Aterosclerosis , Enfermedades Cardiovasculares/mortalidad , Enfermedades Cardiovasculares/prevención & control , Humanos , Inflamación/complicaciones , Metotrexato/administración & dosificación , Infarto del Miocardio/complicaciones , Proyectos de InvestigaciónRESUMEN
Outpatient Trials in the Covid-19 Era and BeyondA group of investigators had a meeting at the National Heart, Lung, and Blood Institute in May 2020 to discuss ways to decrease thrombotic complications among symptomatic outpatients with Covid-19. The investigators discuss their approach to three specific challenges: conducting a trial remotely, working through regulatory hurdles, and recruiting a diverse population of participants.
Asunto(s)
COVID-19 , Humanos , Pacientes Ambulatorios , SARS-CoV-2 , Ensayos Clínicos Controlados Aleatorios como AsuntoAsunto(s)
Benzoxazoles , Pie Diabético , Gangrena , Humanos , Pie Diabético/tratamiento farmacológico , Pie Diabético/complicaciones , Gangrena/etiología , Benzoxazoles/uso terapéutico , Butiratos/farmacología , Butiratos/uso terapéutico , Masculino , Femenino , Persona de Mediana Edad , Resultado del TratamientoRESUMEN
BACKGROUND: Randomized trials have largely failed to support an effect of antioxidant vitamins on the risk of cardiovascular disease (CVD). Few trials have examined interactions among antioxidants, and, to our knowledge, no previous trial has examined the individual effect of ascorbic acid (vitamin C) on CVD. METHODS: The Women's Antioxidant Cardiovascular Study tested the effects of ascorbic acid (500 mg/d), vitamin E (600 IU every other day), and beta carotene (50 mg every other day) on the combined outcome of myocardial infarction, stroke, coronary revascularization, or CVD death among 8171 female health professionals at increased risk in a 2 x 2 x 2 factorial design. Participants were 40 years or older with a history of CVD or 3 or more CVD risk factors and were followed up for a mean duration of 9.4 years, from 1995-1996 to 2005. RESULTS: A total of 1450 women experienced 1 or more CVD outcomes. There was no overall effect of ascorbic acid (relative risk [RR], 1.02; 95% CI, 0.92-1.13 [P = .71]), vitamin E (RR, 0.94; 95% CI, 0.85-1.04 [P = .23]), or beta carotene (RR, 1.02; 95% CI, 0.92-1.13 [P = .71]) on the primary combined end point or on the individual secondary outcomes of myocardial infarction, stroke, coronary revascularization, or CVD death. A marginally significant reduction in the primary outcome with active vitamin E was observed among the prespecified subgroup of women with prior CVD (RR, 0.89; 95% CI, 0.79-1.00 [P = .04]; P value for interaction, .07). There were no significant interactions between agents for the primary end point, but those randomized to both active ascorbic acid and vitamin E experienced fewer strokes (P value for interaction, .03). CONCLUSION: There were no overall effects of ascorbic acid, vitamin E, or beta carotene on cardiovascular events among women at high risk for CVD.
Asunto(s)
Antioxidantes/uso terapéutico , Ácido Ascórbico/uso terapéutico , Enfermedades Cardiovasculares/prevención & control , Vitamina E/uso terapéutico , Vitaminas/uso terapéutico , beta Caroteno/uso terapéutico , Adulto , Anciano , Método Doble Ciego , Femenino , Humanos , Persona de Mediana EdadRESUMEN
CONTEXT: Recent randomized trials among patients with preexisting cardiovascular disease (CVD) have failed to support benefits of B-vitamin supplementation on cardiovascular risk. Observational data suggest benefits may be greater among women, yet women have been underrepresented in published randomized trials. OBJECTIVE: To test whether a combination of folic acid, vitamin B6, and vitamin B12 lowers risk of CVD among high-risk women with and without CVD. DESIGN, SETTING, AND PARTICIPANTS: Within an ongoing randomized trial of antioxidant vitamins, 5442 women who were US health professionals aged 42 years or older, with either a history of CVD or 3 or more coronary risk factors, were enrolled in a randomized, double-blind, placebo-controlled trial to receive a combination pill containing folic acid, vitamin B6, and vitamin B12 or a matching placebo, and were treated for 7.3 years from April 1998 through July 2005. INTERVENTION: Daily intake of a combination pill of 2.5 mg of folic acid, 50 mg of vitamin B6, and 1 mg of vitamin B12. MAIN OUTCOME MEASURES: A composite outcome of myocardial infarction, stroke, coronary revascularization, or CVD mortality. RESULTS: Compared with placebo, a total of 796 women experienced a confirmed CVD event (406 in the active group and 390 in the placebo group). Patients receiving active vitamin treatment had similar risk for the composite CVD primary end point (226.9/10,000 person-years vs 219.2/10,000 person-years for the active vs placebo group; relative risk [RR], 1.03; 95% confidence interval [CI], 0.90-1.19; P = .65), as well as for the secondary outcomes including myocardial infarction (34.5/10,000 person-years vs 39.5/10,000 person-years; RR, 0.87; 95% CI, 0.63-1.22; P = .42), stroke (41.9/10,000 person-years vs 36.8/10,000 person-years; RR, 1.14; 95% CI, 0.82-1.57; P = .44), and CVD mortality (50.3/10,000 person-years vs 49.6/10,000 person-years; RR, 1.01; 95% CI, 0.76-1.35; P = .93). In a blood substudy, geometric mean plasma homocysteine level was decreased by 18.5% (95% CI, 12.5%-24.1%; P < .001) in the active group (n = 150) over that observed in the placebo group (n = 150), for a difference of 2.27 micromol/L (95% CI, 1.54-2.96 micromol/L). CONCLUSION: After 7.3 years of treatment and follow-up, a combination pill of folic acid, vitamin B6, and vitamin B12 did not reduce a combined end point of total cardiovascular events among high-risk women, despite significant homocysteine lowering. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00000541.
Asunto(s)
Enfermedades Cardiovasculares/prevención & control , Suplementos Dietéticos , Ácido Fólico/uso terapéutico , Vitamina B 12/uso terapéutico , Vitamina B 6/uso terapéutico , Complejo Vitamínico B/uso terapéutico , Adulto , Anciano , Enfermedades Cardiovasculares/mortalidad , Método Doble Ciego , Combinación de Medicamentos , Femenino , Ácido Fólico/sangre , Homocisteína/sangre , Humanos , Persona de Mediana Edad , RiesgoRESUMEN
BACKGROUND: The aim of this study was to determine whether reducing plasma homocysteine concentrations with long-term, combined treatment with folic acid, vitamin B6, and vitamin B12 alters plasma biomarkers of inflammation and endothelial dysfunction in women at increased risk of cardiovascular disease. METHODS AND RESULTS: We conducted a blood substudy of 300 treatment-adherent participants (150 in the active treatment group, 150 in the placebo group) in the WAFACS (Women's Antioxidant and Folic Acid Cardiovascular Study), a randomized, double-blind, placebo-controlled trial testing a daily combination of folic acid (2.5 mg), vitamin B6 (50 mg), vitamin B12 (1 mg), or matching placebo, in cardiovascular disease prevention among women at increased risk of cardiovascular disease. Plasma concentration of 3 biomarkers of inflammation (C-reactive protein, interleukin-6, and fibrinogen) and a biomarker of endothelial dysfunction (intercellular adhesion molecule 1) were measured at baseline and at the end of treatment and follow-up. After 7.3 years of combined treatment with folic acid, vitamin B6, and vitamin B12, homocysteine concentrations were reduced by 18% in the active treatment group as compared with the placebo group (P<0.001). However, there was no difference between treatment groups in change in blood concentration from baseline to follow-up for C-reactive protein (P=0.77), interleukin-6 (P=0.91), intercellular adhesion molecule 1 (P=0.38), or fibrinogen (P=0.68). CONCLUSIONS: These findings indicate that long-term, combined treatment with folic acid, vitamin B6, and vitamin B12 lowers homocysteine concentrations, but does not alter major biomarkers of vascular inflammation, consistent with the lack of clinical cardiovascular disease benefit in the trial. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00000541.
Asunto(s)
Enfermedades Cardiovasculares/tratamiento farmacológico , Endotelio Vascular/efectos de los fármacos , Ácido Fólico/uso terapéutico , Mediadores de Inflamación/sangre , Inflamación/tratamiento farmacológico , Vitamina B 12/uso terapéutico , Vitamina B 6/uso terapéutico , Vitaminas/uso terapéutico , Anciano , Biomarcadores/sangre , Enfermedades Cardiovasculares/sangre , Enfermedades Cardiovasculares/diagnóstico , Enfermedades Cardiovasculares/fisiopatología , Método Doble Ciego , Combinación de Medicamentos , Endotelio Vascular/metabolismo , Endotelio Vascular/fisiopatología , Femenino , Ácido Fólico/efectos adversos , Homocisteína/sangre , Humanos , Inflamación/sangre , Inflamación/diagnóstico , Inflamación/fisiopatología , Persona de Mediana Edad , Factores de Tiempo , Resultado del Tratamiento , Vitamina B 12/efectos adversos , Vitamina B 6/efectos adversos , Vitaminas/efectos adversosRESUMEN
BACKGROUND: The evidence for a potential benefit of antioxidant vitamins and folic acid in cardiovascular disease (CVD) prevention is derived from laboratory, clinical, and observational epidemiological studies but remains inconclusive. Large-scale randomized trials with clinical end points are necessary to minimize confounding and provide unbiased estimates of the balance of benefits and risks, yet data from such trials are scarce, especially among women. METHODS: The Women's Antioxidant Cardiovascular Study (WACS) is a randomized, double-blind, placebo-controlled trial testing whether antioxidant vitamins and a folic acid/vitamin B(6)/vitamin B(12) combination prevent future cardiovascular events among women with preexisting CVD or >or=3 CVD risk factors. This paper describes the design of the trial and baseline characteristics of participants, evaluates the success of randomization, and addresses the generalizability of future findings. RESULTS: In a factorial design, 8171 U.S. female health professionals aged >or=40 years were randomized to vitamin E, vitamin C, beta-carotene, or placebos. Of these women, 5442 were also subsequently randomized to folic acid/vitamin B(6)/vitamin B(12) or placebo. The randomization was successful, as evidenced by similar distributions of baseline demographic, health, and behavioral characteristics across treatment groups. The clinical profile of participants was similar to that observed in another large trial of women with CVD. CONCLUSIONS: The similar distribution of known potential confounders across treatment groups provides reassurance that unmeasured or unknown potential confounders are also equally distributed. Although a definitive conclusion regarding generalizability requires additional trials in diverse populations, there is little biological basis for supposing that the benefit-risk balance differs in other high-risk women.
Asunto(s)
Antioxidantes/administración & dosificación , Enfermedades Cardiovasculares/prevención & control , Ácido Fólico/administración & dosificación , Vitamina B 12/administración & dosificación , Vitamina B 6/administración & dosificación , Adulto , Anciano , Método Doble Ciego , Femenino , Humanos , Persona de Mediana Edad , Enfermeras y Enfermeros , Selección de Paciente , Placebos , Factores de Riesgo , Encuestas y Cuestionarios , Salud de la MujerRESUMEN
Data from laboratory studies, observational research, and/or secondary prevention trials suggest that vitamin D and marine omega-3 fatty acids may reduce risk for cancer or cardiovascular disease (CVD), but primary prevention trials with adequate dosing in general populations (i.e., unselected for disease risk) are lacking. The ongoing VITamin D and OmegA-3 TriaL (VITAL) is a large randomized, double-blind, placebo-controlled, 2 x 2 factorial trial of vitamin D (in the form of vitamin D(3) [cholecalciferol], 2000 IU/day) and marine omega-3 fatty acid (Omacor fish oil, eicosapentaenoic acid [EPA]+docosahexaenoic acid [DHA], 1g/day) supplements in the primary prevention of cancer and CVD among a multi-ethnic population of 20,000 U.S. men aged ≥ 50 and women aged ≥ 55. The mean treatment period will be 5 years. Baseline blood samples will be collected in at least 16,000 participants, with follow-up blood collection in about 6000 participants. Yearly follow-up questionnaires will assess treatment compliance (plasma biomarker measures will also assess compliance in a random sample of participants), use of non-study drugs or supplements, occurrence of endpoints, and cancer and vascular risk factors. Self-reported endpoints will be confirmed by medical record review by physicians blinded to treatment assignment, and deaths will be ascertained through national registries and other sources. Ancillary studies will investigate whether these agents affect risk for diabetes and glucose intolerance; hypertension; cognitive decline; depression; osteoporosis and fracture; physical disability and falls; asthma and other respiratory diseases; infections; and rheumatoid arthritis, systemic lupus erythematosus, thyroid diseases, and other autoimmune disorders.
Asunto(s)
Enfermedades Cardiovasculares/prevención & control , Suplementos Dietéticos , Ácidos Grasos Omega-3/administración & dosificación , Neoplasias/prevención & control , Prevención Primaria/métodos , Vitamina D/administración & dosificación , Método Doble Ciego , Femenino , Aceites de Pescado , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Resultado del Tratamiento , Vitaminas/administración & dosificaciónRESUMEN
BACKGROUND: Observational studies suggested that a diet high in fruits and vegetables, both of which are rich with antioxidants, may prevent cancer development. However, findings from randomized trials of the association between antioxidant use and cancer risk have been mostly negative. METHODS: From 8171 women who were randomly assigned in the Women's Antioxidant Cardiovascular Study, a double-blind, placebo-controlled 2 x 2 x 2 factorial trial of vitamin C (500 mg of ascorbic acid daily), natural-source vitamin E (600 IU of alpha-tocopherol every other day), and beta carotene (50 mg every other day), 7627 women who were free of cancer before random assignment were selected for this study. Diagnoses and deaths from cancer at a specific site were confirmed by use of hospital reports and the National Death Index. Cox proportional hazards regression models were used to assess hazard ratios (represented as relative risks [RRs]) of common cancers associated with use of antioxidants, either individually or in combination. Subgroup analyses were conducted to determine if duration of use modified the association of supplement use with cancer risk. All statistical tests were two-sided. RESULTS: During an average 9.4 years of treatment, 624 women developed incident invasive cancer and 176 women died from cancer. There were no statistically significant effects of use of any antioxidant on total cancer incidence. Compared with the placebo group, the RRs were 1.11 (95% confidence interval [CI] = 0.95 to 1.30) in the vitamin C group, 0.93 (95% CI = 0.79 to 1.09) in the vitamin E group, and 1.00 (95% CI = 0.85 to 1.17) in the beta carotene group. Similarly, no effects of these antioxidants were observed on cancer mortality. Compared with the placebo group, the RRs were 1.28 (95% CI = 0.95 to 1.73) in the vitamin C group, 0.87 (95% CI = 0.65 to 1.17) in the vitamin E group, and 0.84 (95% CI = 0.62 to 1.13) in the beta carotene group. Duration and combined use of the three antioxidants also had no effect on cancer incidence and cancer death. CONCLUSIONS: Supplementation with vitamin C, vitamin E, or beta carotene offers no overall benefits in the primary prevention of total cancer incidence or cancer mortality.