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: 10550263
• 负责人: Katherine Teresa Mills
• 金额: $ 68.49万
• 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/10550263
• 关键词: Academy; Adherence; African American; African American population; Albuminuria; Ambulatory Blood Pressure Monitoring; Aorta; 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; Femur; 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; Observational Study; Organ; Outcome; Outcome Study; Participant; Patients; Physiologic pulse; Play; Potassium; Protocols documentation; Quality Control; Randomized; Randomized, Controlled Trials; Recommendation; Recording of previous events; Reporting; Risk Factors; Role; Side; Sodium; Standardization; State Medicine; Structure; Testing; Ventricular; Woman; aged; arterial stiffness; biomarker validation; blood pressure control; 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; risk prediction; 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.

项目总结