Effects of a postnatal high-salt diet on cardiac function in offspring from hypoxic pregnancies

Prenatal hypoxia is a common pregnancy complication that can permanently alter the structure and function of the fetal heart and predispose individuals to cardiovascular disease. However, the interactive effects of prenatal hypoxia and postnatal lifestyle choices are poorly studied. This study investigated the combined effects of prenatal hypoxia and a postnatal high-salt diet on cardiac function in adulthood. Pregnant Wistar rats were exposed to either 21% oxygen (normoxic group, n = 8) or 10.5% oxygen (hypoxic group, n = 8) from day 15-20 of gestation. Male offspring were divided into two groups at 5 weeks of age; normal salt (0.3 % NaCl) and high salt (8% NaCl) chow. Blood pressure and echocardiography measurements were performed at 18 weeks to assess cardiovascular function. Rats from hypoxic pregnancies had pulmonary hypertension and right ventricular thickening; whereas rats fed a postnatal high-salt diet had systemic hypertension, left ventricular wall thickening, and a reduced myocardial performance index. When prenatal hypoxia was combined with a postnatal high-salt diet, the rats exhibited a combination of the two phenotypes, but there were no significant interactions. Results suggest postnatal diet can worsen cardiovascular outcomes in offspring from hypoxic pregnancies, which can have significant implications for disease management.

产前缺氧（Prenatal hypoxia）是一种常见的妊娠并发症（pregnancy complication），可永久性改变胎儿心脏（fetal heart）的结构与功能，并使个体易患心血管疾病（cardiovascular disease）。然而，产前缺氧与产后生活方式选择（postnatal lifestyle choices）的交互作用（interactive effects）研究尚不充分。本研究旨在探讨产前缺氧与产后高盐饮食对成年期心功能（cardiac function）的联合效应（combined effects）。怀孕的Wistar大鼠于妊娠第15至20天暴露于21%氧气（常氧组，n=8）或10.5%氧气（缺氧组，n=8）。雄性后代在5周龄时分为两组：正常盐（0.3% NaCl）组与高盐（8% NaCl）饲料组。18周时进行血压与超声心动图测量（echocardiography measurements），以评估心血管功能。缺氧妊娠组的大鼠表现出肺动脉高压（pulmonary hypertension）与右心室增厚；而产后高盐饮食喂养的大鼠则呈现系统性高血压（systemic hypertension）、左心室壁增厚及心肌性能指数（myocardial performance index）降低。当产前缺氧与产后高盐饮食结合时，大鼠表现出两种表型（phenotypes）的组合，但无显著交互作用。研究结果表明，产后饮食可恶化缺氧妊娠后代的心血管结局，这对疾病管理具有重要意义。