A low molecular weight heparin decreases plasma aldosterone in patients with primary hyperaldosteronism.

Four patients with primary hyperaldosteronism were treated with nadroparin 4100 or 6150 antiXa IU daily for 4 days. Plasma and urine sodium and potassium, and plasma aldosterone and renin were monitored before, during and after the study. After four days of treatment, and for the following two days, plasma aldosterone was decreased (by a mean of 49% on Day 6), and urinary Na/K was increased (3.7-fold). The direction of the changes was reversed on Day 8. The study has confirmed the effect of low molecular weight heparin on aldosterone, and makes it unlikely that it is related to inhibition of angiotensin II stimulation in these patients, as renin could not be detected in their plasma.