Investigating high blood pressure and gut leakiness

Investigating the relationship between blood pressure and gut permeability in normotensive and hypertensive patients

Status

Recruiting

Phases

Unknown

Study type

Observational

Source

ANZCTR

Registry ID

ACTRN12624000112561

Enrollment

Registered

2024-02-08

Start date

2024-02-26

Completion date

2024-12-16

Last updated

2024-08-12

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

Conditions

None listed

Brief summary

High blood pressure, or hypertension, is a highly prevalent chronic disease, affecting 1 in 3 people in Australia. It is a disease where the blood inside the heart and blood vessels is pumped with more force than normal. This adds stress to these important organs, increasing the chance of having a heart attack or a stroke. We have shown that changes in the gut bacteria happen in hypertension. We think that these changes in the gut bacteria may disrupt intestinal permeability, also known as “leaky gut”. But we don’t know much about the relationship between blood pressure and leaky gut. This research will measure blood pressure and gut leakiness in people with normal and high blood pressure. By learning about the relationship between gut leakiness and blood pressure, we may be able to design drug and diet therapies that make the gut less leaky, to help people with high blood pressure. This research does not involve being given any treatments (e.g. drugs, special diets) for blood pressure.

Interventions

Participants will have blood pressure measured in the office (over 3 times, after being seated for 5 minutes) and over 24 hours with an ambulatory blood pressure device (every 15 minutes during the day and every 30 minutes during the night), Participants will have gastrointestinal permeability assessed using the multisugar test. In this test participants consume a solution of sugars (sucrose, lactulose, L-rhamnose, erythritol and sucralose) and collect urine for 24 hours. This test will be administered by a research officer. Participants will have gastrointestinal transit time assessed using the blue muffin test. In this test participants consume a regular muffin made using blue food colouring, and record the time taken until blue/green colour is observed in the faeces. This test will be administered by a research officer. Participants will have plasma collected (once) and fecal samples self-collected (once). There are an additional, optional three fecal self collections occurring weekly post-enrolment. Participants will record their dietary intake for 3 days. Participants will complete a quality of life survey, several cognitive tests (from NIH Toolbox), a sleep survey, a depression/anxiety survey and a gastrointestinal symptoms survey.

Eligibility

Sex/Gender

All

Age

18 Years to 75 Years

Healthy volunteers

Yes

Inclusion criteria

Inclusion criteria: • Ability to give informed consent. • 18-75 years of age • BMI 18.5-40 kg/m2 • Either sex For normotensive participants: - Not taking antihypertensive medications AND - 24 hour ambulatory blood pressure monitoring results of Systolic blood pressure <130 mmHg and diastolic blood pressure <80 mmHg For untreated hypertensive participants: - Not taking antihypertensive medications AND - 24 hour ambulatory blood pressure monitoring results of Systolic blood pressure >130 mmHg and diastolic blood pressure >80 mmHg For treated hypertensive participants: - Taking 1-2 antihypertensive medications, regardless of blood pressure results OR - Taking 3 or more antihypertensive medications including a diuretic AND -24 hour ambulatory blood pressure monitoring results of Systolic blood pressure <130 mmHg and diastolic blood pressure <80 mmHg For resistant hypertensive participants: - Taking 3 or more antihypertensive medications including a diuretic AND - 24 hour ambulatory blood pressure monitoring results of Systolic blood pressure >130 mmHg and diastolic blood pressure >80 mmHg

Exclusion criteria

• Alzheimers, dementia or other unsoundness of mind • Recent use of antibiotics (<3 months) or probiotics (< 6 weeks) • Pregnant or lactating women • Presence of gastrointestinal diseases (including ulcerative colitis, crohn’s disease, inflammatory bowel disease, lactose intolerance, celiac disease, chronic pancreatitis or other malabsorption disorder). • Previous gastrointestinal surgery. • Renal dysfunction with an eGFR < 45. • ADHD stimulant medications (as this may affect blood pressure) • Office blood pressure over/equal to 165/100 mmHg – these participants will be advised to see their GPs as guidelines suggest antihypertensive therapy should be started soon.

Outcome results