A Mechanistic Trial of Dietary Sodium Reduction on Vascular Structure and Function in African Americans

膳食钠减少对非裔美国人血管结构和功能的机制试验

• 批准号: 10365668
• 负责人: Katherine Teresa Mills
• 金额: $ 68.68万
• 依托单位: TULANE UNIVERSITY OF LOUISIANA
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-01-17 至 2026-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10365668
• 关键词: Academy; Adherence; African American; African American population; Albuminuria; Ambulatory Blood Pressure Monitoring; Area; Behavior Therapy; Blood Pressure; Blood Vessels; Cardiac; Cardiovascular Diseases; Cardiovascular system; Chronic Disease; Chronic Kidney Failure; Clinic Visits; Clinical; Cohort Studies; Control Groups; Diet; Dietary Sodium; Dietitian; Disease Outcome; EFRAC; Endothelium; Etiology; Event; Exclusion Criteria; Heart; Heart Atrium; Hour; Hypertension; Impairment; Incidence; Intake; Intention; Intervention; Knowledge; Left; Left Ventricular Ejection Fraction; Left Ventricular Hypertrophy; Left Ventricular Mass; Measures; Mediating; Medicine; Monitor; Observational Study; Organ; Outcome; Outcome Study; Participant; Patients; Physiologic pulse; Play; Potassium; Protocols documentation; Quality Control; Randomized; Randomized Controlled Trials; Recording of previous events; Reporting; Risk Factors; Role; Side; Sodium; Standardization; State Medicine; Structure; Testing; Ventricular; Woman; aged; arterial stiffness; blood pressure elevation; blood pressure reduction; cardiac magnetic resonance imaging; cardiovascular disorder prevention; cardiovascular disorder risk; cardiovascular risk factor; clinical risk; clinically significant; dietary; endothelial dysfunction; high risk; improved; indexing; men; mortality; primary outcome; recruit; renal damage; secondary analysis; targeted biomarker

Project Summary High dietary sodium intake increases risk of cardiovascular disease (CVD) independent of established risk factors, including blood pressure (BP). Non-BP mediated mechanisms underlying the increased risk of CVD associated with dietary sodium intake are not well understood, but observational studies suggest direct target organ damage in the heart and vasculature might play an important role. Little evidence exists from randomized controlled trials (RCTs) on target organ effects of dietary sodium reduction, and the National Academy of Medicine has recommended future research to “test the effects of different sodium intake levels on endothelial and vascular function” in order to “to better characterize the relationship between sodium intake and chronic disease”. Further, no RCTs have been powered to test the effect of dietary sodium reduction on subclinical cardiovascular structure and function in African Americans, who are more sensitive to dietary sodium intake and at higher risk for CVD. The overall objective of the proposed mechanistic trial is to test the effect of dietary sodium reduction on cardiac and vascular structure and function. Specifically, the proposed trial will test whether dietary sodium reduction (targeting a dietary sodium intake of <2,300 mg/day) will improve left ventricular mass index (LVMI), left ventricular global longitudinal strain (LVGLS), carotid-femoral pulse wave velocity (cfPWV), and flow-mediated dilation (FMD) compared to usual intake. Additionally, we will test whether this effect is independent from BP reduction. We will recruit 240 African Americans with elevated BP or hypertension from the greater New Orleans area and randomly assign them to a dietitian-led behavioral intervention aimed at decreasing dietary sodium intake to <2,300 mg/day for 12 months or to a usual diet. Study outcomes, including cardiac magnetic resonance imaging (CMR)-determined LVMI and LVGLS, cfPWV, and FMD, will be measured at baseline, 6-month, and 12-month clinic visits using standardized protocols with stringent quality control. These outcomes are validated biomarkers for target organ damage and predict the risk of clinical CVD events. In primary analyses, the effect of sodium reduction on each subclinical CVD endpoint will be compared between the sodium reduction and usual diet groups according to the intention-to- treat principle without adjusting for covariates. In secondary analyses, changes in ambulatory and clinical BP will be adjusted to assess the BP-independent effect of dietary sodium reduction on each subclinical CVD endpoint. The proposed trial has 85% statistical power to detect a clinically significant difference in changes of the four co-primary outcomes (10 g/m2 in LVMI, 1.3% in LVGLS, 0.9 m/s in cfPWV, and 1.1% in FMD) over 12 months between the two groups at a 2-sided significance level of 0.0125 (0.05/4). This study is the first RCT to test the effect of dietary sodium reduction on subclinical CVD endpoints in African Americans. Findings from this trial will fill the knowledge gap of the underlying mechanisms of dietary sodium intake on CVD risk and provide further evidence on sodium reduction for CVD prevention.

项目摘要 高饮食钠摄入量增加了与已建立风险无关的心血管疾病（CVD）的风险 因素，包括血压（BP）。 CVD风险增加的基础的非BP介导的机制 与饮食钠摄入相关的尚不清楚，但是观察性研究表明直接靶标 心脏和脉管系统中的器官损害可能起着重要作用。很少有证据来自 随机对照试验（RCT）对饮食钠减少的靶器官影响和国家 医学院建议未来的研究来“测试不同钠摄入水平对 内皮和血管功能”，以更好地表征钠摄入量之间的关系 和慢性疾病”。此外，没有动力来测试减少饮食钠对 非裔美国人的亚临床心血管结构和功能，对饮食更敏感 钠摄入量，CVD风险更高。拟议的机械试验的总体目的是测试 饮食钠还原对心脏和血管结构和功能的影响。具体而言，提议 试验将测试减少饮食钠的减少（靶向饮食钠摄入量<2,300 mg/天） 改善左心室质量指数（LVMI），左心室全局纵向应变（LVGLS），颈动脉 - 股骨 与通常的摄入量相比，脉冲波速度（CFPWV）和流介导的词典（FMD）。此外，我们会的 测试这种效果是否独立于BP减少。我们将招募240名升高的非洲裔美国人 BP或大型新奥尔良地区的高血压，并将其随机分配给营养师领导的行为 干预措施旨在将饮食中的钠摄入量降低至2,300毫克/天或平常的饮食。 研究结果，包括心脏磁共振成像（CMR）确定的LVMI和LVGL，CFPWV， 和FMD，将在基线，6个月和12个月的诊所使用标准方案进行测量 严格的质量控制。这些结果是验证目标器官损害的生物标志物，并预测 临床CVD事件的风险。在主要分析中，钠还原对每个亚临床CVD的影响 根据意向性，将比较减少钠和常规饮食组的终点 处理原理而无需调整协变量。在二次分析中，卧床和临床BP的变化 将进行调整以评估饮食中钠降低对每个亚临床CVD的无关依赖性的影响 端点。拟议的试验具有85％的统计能力，可以检测到临床上的显着差异 超过12个共同结果（LVMI中的10 g/m2，LVGL中的1.3％，CFPWV中的0.9 m/s，FMD中的1.1％）超过12 两组之间的几个月在2面显着性水平为0.0125（0.05/4）。这项研究是第一个RCT 测试减少饮食钠对非裔美国人亚临床CVD终点的影响。来自 该试验将填补饮食钠摄入CVD风险和 提供有关减少CVD预防钠的进一步证据。