Sodium-sensitive hypertension. Implications of pathogenesis for therapy

Area of Science:

• Nephrology
• Cardiovascular Medicine
• Endocrinology

Background:

• Clinical hypertension is often sodium-sensitive, but known causes explain only a small fraction.
• A subset of normal-renin hypertensives exhibits abnormal vascular and adrenal responses to angiotensin II.
• These patients demonstrate impaired sodium handling and blood pressure elevation with high salt intake.

Purpose of the Study:

• To identify and characterize a novel group of normal-renin hypertensive patients.
• To investigate the underlying mechanisms of abnormal sodium balance and blood pressure regulation.
• To explore the potential genetic basis and therapeutic targets for this hypertension subtype.

Main Methods:

• Patient phenotyping including assessment of sodium balance and blood pressure response to dietary salt shifts.
• Evaluation of renal vascular and adrenal responsiveness to angiotensin II.
• Pharmacological intervention with converting enzyme inhibitors and calcium channel blockers.

Main Results:

• Identified normal-renin hypertensives with impaired ability to modulate renal vascular and adrenal responsiveness to angiotensin II.
• These patients exhibit abnormal sodium handling, positive sodium balance on high-salt diets, and increased blood pressure with salt loading.
• Converting enzyme inhibition normalized renal blood flow, corrected altered responsiveness, improved sodium handling, and reduced blood pressure.

Conclusions:

• A distinct, likely inherited, form of hypertension is characterized by abnormal angiotensin II responsiveness and sodium handling.
• Converting enzyme inhibition represents a potential therapeutic strategy for this common hypertension subtype.
• The findings suggest a significant genetic contribution to this prevalent form of hypertension.