Beyond Blood Pressure: Salt Sensitivity as a Cardiorenal Phenotype-A Narrative Review

Area of Science:

• Cardiovascular Medicine
• Nephrology
• Hypertension Research

Background:

• Salt-sensitive blood pressure (SSBP) is an underrecognized hypertensive phenotype where blood pressure and volume status are heavily influenced by dietary sodium.
• It involves complex interactions of renal sodium handling, neurohormonal activation, vascular dysfunction, and inflammation, contributing to kidney injury and cardiac remodeling.
• SSBP is linked to chronic kidney disease (CKD) and heart failure with preserved ejection fraction (HFpEF), highlighting its clinical significance.

Purpose of the Study:

• To review current mechanistic and clinical evidence on SSBP.
• To focus on pathophysiology, cardiorenal interactions, diagnostic challenges, and practical, phenotype-guided therapeutic strategies.

Main Methods:

• A narrative literature review was performed using major scientific databases (PubMed, Scopus, Web of Science).
• Integration of experimental, translational, and clinical studies, alongside guideline documents, for comprehensive interpretation.

Main Results:

• Key mechanisms include impaired renal sodium excretion, intrarenal RAAS activation, sympathetic overactivity, endothelial dysfunction, and inflammation, affecting the kidney-heart axis.
• Clinical manifestations include non-dipping BP, albuminuria, edema, and predisposition to HFpEF.
• Dynamic BP monitoring and targeted lab assessments aid in identifying SSBP and guiding management.

Conclusions:

• Early identification of SSBP allows for interventions beyond general sodium restriction.
• Phenotype-guided therapies, including lifestyle changes and specific drug classes (RAAS blockade, diuretics, MRAs, SGLT2i), may enhance cardiorenal outcomes.
• Emerging technologies for BP and sodium monitoring show promise for personalized management.