Salt sensitivity in humans is associated with abnormal acid-base regulation

Area of Science:

• Nephrology
• Cardiovascular Physiology
• Acid-Base Balance

Background:

• Metabolic acidosis is observed in rat models of salt-sensitive genetic hypertension.
• Investigating acid-base homeostasis in salt sensitivity in humans is crucial.

Purpose of the Study:

• To test the hypothesis that salt sensitivity in humans is linked to abnormal acid-base homeostasis.
• To determine the relationship between salt intake, blood pressure, and acid-base parameters in salt-sensitive and salt-resistant individuals.

Main Methods:

• Arterial blood gas analyses were performed on 40 normotensive subjects on controlled low and high sodium chloride diets.
• A subset received sodium citrate to assess its effect on acid-base balance.
• Blood pressure, arterial pH, and bicarbonate levels were measured during each dietary regimen.

Main Results:

• Salt-sensitive subjects (n=16) showed significantly lower arterial pH and bicarbonate levels during high sodium chloride intake compared to salt-resistant subjects (n=24).
• Increased blood pressure from sodium chloride correlated inversely with arterial pH and bicarbonate levels.
• Sodium chloride raised blood pressure in salt-sensitive subjects, while sodium citrate did not and improved acid-base balance.

Conclusions:

• Salt sensitivity in humans is associated with impaired renal acid-base regulation.
• Abnormalities in pH and bicarbonate levels during high salt intake may contribute to salt-sensitive hypertension.
• Further research into renal mechanisms of acid-base regulation in hypertension is warranted.