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

Area of Science:

• Cardiovascular Physiology
• Developmental Biology
• Environmental Health

Background:

• Prenatal hypoxia is a known risk factor for congenital heart defects and adult cardiovascular disease.
• The impact of postnatal lifestyle, such as diet, on individuals exposed to prenatal hypoxia is not well understood.
• Understanding these combined effects is crucial for developing preventative strategies against cardiovascular disease.

Purpose of the Study:

• To investigate the combined effects of prenatal hypoxia and a postnatal high-salt diet on adult cardiac structure and function.
• To determine if prenatal hypoxia and postnatal high-salt diet interact synergistically to impact cardiovascular health.
• To assess the implications for cardiovascular disease management in offspring of pregnancies complicated by hypoxia.

Main Methods:

• Pregnant Wistar rats were exposed to normoxia (21% O2) or hypoxia (10.5% O2) during late gestation (days 15-20).
• Male offspring were fed either a normal-salt (0.3% NaCl) or high-salt (8% NaCl) diet from 5 weeks of age.
• Cardiovascular function was assessed at 18 weeks using blood pressure measurements and echocardiography.

Main Results:

• Offspring from hypoxic pregnancies exhibited pulmonary hypertension and right ventricular thickening.
• Offspring on a high-salt diet developed systemic hypertension, left ventricular thickening, and impaired relaxation.
• Combined prenatal hypoxia and postnatal high-salt diet led to a combination of these phenotypes without significant interaction.

Conclusions:

• Prenatal hypoxia and postnatal high-salt diet induce distinct cardiovascular abnormalities.
• A high-salt diet exacerbates cardiovascular strain in offspring exposed to prenatal hypoxia, even without synergistic interaction.
• These findings underscore the importance of managing postnatal diet in individuals with a history of prenatal hypoxia to mitigate cardiovascular disease risk.