Increased Salt-Sensitive Blood Pressure in Women vs Men: Is Relative Hyperaldosteronism the Mechanism?

Abstract

Context: Women vs men have more salt-sensitive blood pressure (SSBP) and higher stimulated aldosterone (ALDO) levels, suggesting that their increased SSBP is secondary to a relative hyper-ALDO state. Contrariwise, men vs women have higher sedentary ALDO levels.

Objective: The present project was designed to address the question are women vs men in a relatively hyper-ALDO state.

Methods: A total of 363 women and 483 men were selected from the HyperPATH cohort to assess the potential underlying mechanism for observed sex differences.

Results: Women had greater SSBP, greater ALDO and vasculature response to angiotensin II (Ang II), and higher upright ALDO/ plasma renin activity, but men on both restricted- and liberal-salt diets had higher basal levels of supine ALDO, PRA levels, and other ALDO secretagogues. Using 24-hour urine ALDOs to assess overall production, ALDO did not differ by sex regardless of salt intake, except when assessed in subsets. Normotensive women vs men had greater urine ALDO, and women vs men younger than 51 had higher urine ALDO.

Conclusion: 1) Lower Ang II responsiveness in Ang II-targeted organs was observed in men vs women. 2) Similar 24-hour urine ALDO levels in women and men do not support the concept that relative hyper-ALDO is the mechanism for sex difference in SSBP. The data also suggest that the SSBP in women, in some cases, may be benign since it is secondary to a BP reduction on the restricted-salt diet, not an increase on the liberal-salt diet.