Impact of vitamin D supplementation on cardiac structure and function

描述（由申请人提供）：实验和观察数据表明，补充维生素D可减少左心室肥大并改善心脏功能。然而，缺乏前瞻性的临床数据。因此，我们建议对维生素D和OmegA-3试验（VITAL）（U 01 CA 138962）进行辅助研究，这是一项在20，000名男性和女性（年龄分别为60岁和65岁）中进行的维生素D补充试验。由于VITAL缺乏对心脏结构和功能的任何直接评估，我们建议在随机化前和3年时对1，000名VITAL受试者进行超声心动图心脏成像。这些数据可以回答母试验未解决的几个重要问题。具体而言，VITAL专注于血管终点（心肌梗死、中风）， 增加了维生素D对心脏本身的重要作用可能被忽略的可能性。由于有令人信服的实验证据表明维生素D对心肌的直接影响，因此无论整个母试验的结果如何，对心脏结构和功能的评估都将提供宝贵的临床和机制见解。研究者在亚临床心血管成像、随机试验协调（包括母公司VITAL研究）以及临床和实验营养研究方面具有丰富的经验。这项研究代表了一个独特的和具有成本效益的机会，在一个大型的，多样化的一级预防试验中调查心脏结构和功能的措施。

DESCRIPTION (provided by applicant): Experimental and observational data suggest that vitamin D supplementation reduces left ventricular hypertrophy and improves cardiac function. Prospective clinical data, however, are lacking. Thus, we propose an ancillary study to the Vitamin D and OmegA-3 Trial (VITAL) (U01CA138962), an outcomes trial of vitamin D supplementation in 20,000 men and women (aged ¿60 and 65 years, respectively). Because VITAL lacks any direct assessment of cardiac structure and function, we propose to perform cardiac imaging with echocardiography in 1,000 VITAL subjects pre-randomization and at 3 years. These data may answer several important questions that are not being addressed by the parent trial. Specifically, VITAL is focused on vascular endpoints (myocardial infarction, stroke), raising the possibility that important effects of vitamin D on the heart itself could be missed. Because there is compelling experimental evidence regarding the direct myocardial effects of vitamin D, assessment of cardiac structure and function would provide invaluable clinical and mechanistic insight, regardless of the outcome of the overall parent trial. The investigators have extensive experience in subclinical cardiovascular imaging, coordination of randomized trials (including the parent VITAL study), and clinical and experimental nutritional research. The study represents a unique and cost- effective opportunity to investigate measures of cardiac structure and function in a large, diverse primary prevention trial.