The renin-angiotensin-aldosterone (RAAS) axis, endothelial function and hypertension: diagnostic strategies, and therapeutic role of potassium supplementation

The renin-angiotensin-aldosterone (RAAS) axis, endothelial function and hypertension: diagnostic strategies, and therapeutic role of potassium supplementation - a randomised cross-over trial and an observational study

Status

Active, not recruiting

Phases

Unknown

Study type

Interventional

Source

ISRCTN

Registry ID

ISRCTN55798944

Enrollment

Registered

2009-06-30

Start date

2008-11-20

Completion date

Unknown

Last updated

2021-01-11

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Hypertension, cardiovascular risk, hyperaldosteronism Circulatory System

Interventions

Study 1: Dietary intake of sodium and potassium will be assessed and a 24 hour urine collection for estimation of Na and K excretion will be taken. The subjects will be randomised to either placebo or

oral) for 6 weeks. There will be a 6 week washout period. Subjects will be studied at baseline, at the end of washout and after each intervention (4 in total). Study 2:

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: Study 1: 1.1. Patients (both males and females) aged 40-70 with moderate (>10%) cardiovascular disease risk (Joint British Societies' [JSB2] guidelines) Study 2: Three groups of participants (both males and females, all within age 18-70): 2.1. Patients with essential hypertension 2.2. Patients with hyperaldosteronism 2.3. Healthy volunteers

Exclusion criteria

Exclusion criteria: Study 1: 1.1. A history or renal or cardiovascular disease 1.2. Fasting glucose >7 mmol/l 1.3. Serum potassium >5.5 mmol/l 1.4. Treated seated blood pressure >140/90 mmHg 1.5. Women on hormone replacement therapy (HRT) 1.6. Pregnancy Study 2: 2.1. Pregnancy

Design outcomes

Primary

Measure	Time frame
Study 1 - Global endothelial function assessed by determining the change in augmentation index (AIx) in response to the administration of nitroglycerin (NTG) and salbutamol. Study 2 - Aldosterone response to synacthen/GnRH All primary and secondary outcomes for Study 1 will be assessed at baseline, at the end of washout and after each intervention.	—

Secondary

Measure	Time frame
Study 1 - Brachial blood pressure, pulse wave velocity, serum potassium, renal function, lipid profile, plasma renin activity and aldosterone levels (taken after at least 30 minutes recumbency). Circulating markers of endothelial function (E selectin, VCAM-1, ICAM-1) and markers of inflammation (IL-6, IL-1 beta, hsCRP) All primary and secondary outcomes for Study 1 will be assessed at baseline, at the end of washout and after each intervention.	—

Measure

Time frame

Study 1 - Brachial blood pressure, pulse wave velocity, serum potassium, renal function, lipid profile, plasma renin activity and aldosterone levels (taken after at least 30 minutes recumbency). Circulating markers of endothelial function (E selectin, VCAM-1, ICAM-1) and markers of inflammation (IL-6, IL-1 beta, hsCRP) All primary and secondary outcomes for Study 1 will be assessed at baseline, at the end of washout and after each intervention.

—

Countries

United Kingdom

Outcome results

None listed

Source: ISRCTN (via WHO ICTRP) · Data processed: Feb 4, 2026