Serum aldosterone and urine electrolytes dynamics in response to DASH diet intervention - An inpatient mechanistic study.

BACKGROUND

Dietary approach to stop hypertension (DASH) diet reduces blood pressure (BP) as effectively as one antihypertensive drug, yet its mechanism of action was never fully characterized.

METHODS

We designed a translational inpatient trial to elucidate the biological pathway leading from nutritional change, through hormonal response, reversal of urine electrolytes ratio, to BP reduction.

RESULTS

A single-center open-label interventional trial. Volunteers were admitted for 14 days, transitioning from an American-style diet to DASH diet. Vital signs, blood, and urine samples were collected daily. Participants completed two 24-hour ambulatory BP measurements (ABPM) and two 24-hour urine collections on days 1 and 10. Nine volunteers completed the protocol. During inpatient stay, serum aldosterone increased from day 0 (mean 8.3 ± 5.0) to day 5 (mean 17.8 ± 5.8) after intervention and decreased on day 11 (mean 11.5 ± 4.7) despite continuous exposure to the same diet (-value = 0.002). Urine electrolyte ratio ([Na]/[K]) decreased significantly from a mean of 3.5 to 1.16 on day 4 ( < 0.001). BP by 24-hour ABPM decreased by a mean of 3.7 mmHg systolic BP and 2.3 mmHg diastolic BP from day 1 to 10.

CONCLUSION

Shifting from a high-sodium/low-potassium diet to the opposite composition leads to aldosterone increase and paradoxical BP reduction. Urine electrolyte ratio reflects nutritional changes and should guide clinicians in assessing adherence to lifestyle modification.