Gastrointestinal-Renal Axis: Role in the Regulation of Blood Pressure.

Hypertension is one of the most common and important health problems worldwide.1 It has been estimated that 29% of the world\u27s adult population, or 1.56 billion people, will have hypertension by the year 2025.2The prevalence of high blood pressure and its adverse consequences result in a heavy burden for hypertensive patients from high‐, middle‐, and low‐income countries.2, 3 Many monogenic causes of hypertension have been reported. However, determining the causes of essential hypertension has been hampered because it is a complex disorder with genetic, epigenetic, and environmental determinants. Among numerous environmental factors, sodium intake is thought to be an important one. Sodium is essential for cellular homeostasis and fluid balance. However, excessive sodium in the body, as a consequence of increased dietary intake and/or impaired excretion, is the most common risk factor for hypertension.4 There is overwhelming evidence that high dietary sodium intake increases the risk for incident hypertension and leads to worse cardiovascular outcomes.4, 5 Excess sodium intake also attenuates the beneficial effects of many antihypertensive drugs, including blockers of the renin–angiotensin system (RAS).6 A modest reduction in dietary salt intake causes a significant fall in blood pressure in both hypertensive and normotensive individuals.7 Therefore, a low‐sodium diet is a major preventive and treatment scheme for hypertension.8 The kidney plays a vital role in the regulation of sodium balance and blood pressure. However, the gastrointestinal (GI) tract, which is the organ first exposed to components of food, has taste receptors and sensors for electrolytes (eg, sodium, potassium, phosphate).9 Therefore, in addition to the kidney, there is increasing realization of the importance of the GI tract in the regulation of sodium balance, and consequently on blood pressure level. For example, GI tract–derived hormones and peptides regulate the autocrine function of renal hormones, affecting renal function, including sodium excretion.10 We have reported that the GI tract–derived hormone, gastrin, and renal receptors synergistically regulate sodium excretion.11 In this article, we present an overview of GI tract–mediated regulation of blood pressure, highlight potential strategies for the prevention and treatment of hypertension, and also attempt a look into the future