Diet and Nitric Oxide (DINO): A Study on the Effects of Dietary Nitrate on Blood Pressure in Subjects With Prehypertension
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- Karolinska Institutet
- Enrollment
- 225
- Locations
- 2
- Primary Endpoint
- Difference in Change in ambulatory Systolic Blood Pressure From Baseline
Study Overview
Brief Summary
The purpose of this study is to examine the effect of different vegetables on cardiovascular function in subjects with moderately increased blood pressure. Specifically we are comparing the effects of vegetables with a high natural content of inorganic nitrate with those of vegetables with a low nitrate content.
Detailed Description
Recent studies indicate that dietary-derived inorganic nitrate can affect blood pressure in humans by converting into nitric oxide bioactivity. Here we will study if vegetables that naturally contain high amounts of nitrate (green leafy vegetables) can lower blood pressure and whether any effect is attributed to the nitrate anion. High nitrate vegetables are compared with vegetables low in nitrate (e.g. tomatoes, sweet pepper). After a 2 week run in period where all subjects receive vegetables low in nitrate, the participants are randomized to one of three interventions. One third of the patients receive high-nitrate vegetables + a placebo pill (KCl), one third receives low-nitrate vegetables + placebo and the third group receives low-nitrate vegetables + a nitrate pill (KNO3). The nitrate content in the pill is precisely matched to the nitrate content in the high-nitrate vegetable group.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Parallel
- Primary Purpose
- Treatment
- Masking
- Double (Participant, Investigator)
Eligibility Criteria
- Ages
- 50 Years to 70 Years (Adult, Older Adult)
- Sex
- All
- Accepts Healthy Volunteers
- Yes
Inclusion Criteria
- •Age 50-70 years Systolic blood pressure >130 at screening visit 2
Exclusion Criteria
- •Systolic blood pressure <120 or >159 mm Hg at screening 2 Systolic blood pressure > 169 mm Hg at screening 1 Chronic kidney disease Chronic rheumatic disease Insulin treated diabetes mellitus Atrial fibrillation Major cardiovascular event within 6 months Inflammatory bowel disease Malignancy, actively treated within 6 months Hepatitis Polycytemia Vera
Arms & Interventions
High nitrate vegetables
During 5 weeks subjects receive 100-150 g of a leafy green vegetable (High nitrate vegetables) per day and placebo pills containing 300 mg KCl (2 x 150 mg).
Intervention: High nitrate vegetables (Other)
Low nitrate vegetables
During 5 weeks subjects receive 100-150 g of tomatoes/sweet pepper (Low nitrate vegetables) per day and placebo pills containing 300 mg KCl (2 x 150 mg).
Intervention: Low nitrate vegetables (Other)
Low nitrate vegetables + nitrate
During 5 weeks subjects receive 100-150 g of tomatoes/sweet pepper (Low nitrate vegetables) per day and nitrate pills containing 300 mg KNO3 (2 x 150 mg).
Intervention: Low nitrate vegetables + nitrate (Dietary Supplement)
Outcomes
Primary Outcomes
Difference in Change in ambulatory Systolic Blood Pressure From Baseline
Time Frame: 5 weeks intervention
Measure how 24h ambulatory SBP changes over 5 weeks with the different interventions
Secondary Outcomes
- Difference in Change in ambulatory diastolic Blood Pressure From Baseline(5 weeks intervention)
- Difference in Change in office diastolic blood pressure (DBP)(Once every week for 5 weeks)
- Difference in Change in flow mediated dilatation (FMD)(5 weeks intervention)
- Difference in Change in office Systolic Blood Pressure From Baseline(5 weeks intervention)
- Difference in Change in Daytime Ambulatory systolic Blood Pressure From Baseline(5 weeks intervention)
Investigators
Jon Lundberg
Professor
Karolinska Institutet