Nutrition, ageing, vascular function, muscular function, metabolic assessment Nutritional, Metabolic, Endocrine
Conditions
Interventions
Volunteers will be randomised to the following groups for 7 days:
1. Nitrate supplementation (concentrated beetroot juice 2 x 70 ml/day, containing ~12.0 mmol of nitrate)
2. Placebo (nitrate-depleted
Sponsors
The Centre for Integrated Research into Musculoskeletal Ageing (UK)
Eligibility
Sex/Gender
All
Inclusion criteria
Inclusion criteria: 1. Non-smoking men and women aged between 60 and 75 years of age 2. English speakers and with a body mass index (BMI) of between 18.5 and 29.9 kg/m2. We have stated that participants must be English speakers because we cannot offer translation services for this study.
Exclusion criteria
Exclusion criteria: 1. Current participation in other research clinical studies 2. Very high resting blood pressure readings (systolic >180 mmHg and/or diastolic >110 mmHg) 3. Vegetarianism (likely to have very high nitrate intake) 4. High physical activity level (>15,000 steps per day; may have BMI in overweight range but low fat mass) 5. Weight change more than 3.0 kg in the last 2 months (important influence on systemic metabolism and vascular function) 6. Active cancer and any diagnosis of malignant cancer in the last 5 years (systemic effects on study outcomes) 7. Diagnosis of chronic and acute metabolic and inflammatory conditions interfering with the study outcome (systemic effects on study outcomes). For example flu, Crohn's disease, rheumatoid arthritis 8. Weight loss medications (sibutramine, orlistat, rimonabant) and history of bariatric surgery (weight loss related changes in systemic metabolism) 9. Previous diagnosis of type 1 or type 2 diabetes treated with insulin and oral hypoglycaemic agents (modification of regulation of intermediate metabolism). Type 2 diabetic patients treated with diet only will be included in the study. 10. Drugs: corticosteroids, sildenafil, aspirin, NSAIDs, diuretics, beta-blockers, antacids, anti-hypertensive (Ca++ channel blockers, ACE inhibitors), statins and any other anti-dyslipidaemic agent, anticoagulants, nitrate-derived agents, anti-cholinergic (all drugs may have an effect on NO production via different mechanisms) 11. Subjects on hormonal therapies (oestrogens, thyroxine, progesteron) and psychiatric drugs (antidepressants, sedatives, antipsychotics) will be excluded if dose has been started/changed in the previous three months (make sure that these disorders are under strict control to avoid interference with the study outcomes) 12. Haematological disorders including self-reported anaemia (risk for the participant and effects on the study outcomes) 13. Major surgical operations interfering with the study outcomes (systemic effects on study outcomes) 14. Alcohol intake >21 units/week for men and >14 units/week for women 15. Blood donations in the previous 3 months
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Oxygen consumption (VO2): all participants will perform a maximal cardiopulmonary exercise stress test with non-invasive gas exchange measurements using the face mask (Metalyzer 3B, Cortex, Leipzig, Germany) on a semi-recumbent cycle ergometer (Corival, Lode, Groningen, Netherlands) using a ramp protocol (10 W/min). These measurements will be performed at each visit. | — |
Secondary
| Measure | Time frame |
|---|---|
| 1. Anthropometry: body weight and height will be measured and subjects? BMI will be calculated. These measurements will be measured at baseline and at the start of each visit (4 visits). 2. Body composition: bioimpedance analysis will be used to measure body fat and muscle mass. These measurements will be performed at the start of each visit. 3. Resting blood pressure: an automated blood pressure monitor will be used to measure resting blood pressure. Three measurements will be performed in a seated position according to standardised protocols. These measurements will be performed at the start of each visit. 4. ECG: a resting 12-lead ECG will be performed at baseline and at the beginning of each visit. In addition, ECG monitoring will be performed during the exercise testing. These measurements will be performed at each visit. 5. Clinical and research biomarkers: a fasting blood sample will be collected at the beginning of each visit. The following biomarkers will be measured: metabolic (glucose, insulin), inflammation (IL-6), oxidative stress (4-HNE), endothelial function (cGMP, ADMA, VEGF) and myokines (fibroblast growth factor-21). 6. Functional tests: assessment of physical performance will be evaluated at each visit using common and validated protocols. These include: hand-grip strength, timed up and go, repeated chair rising test, walking speed. These measurements will be performed at the start of each visit. 7. Bio-reactance technology: non-invasive central hemodynamic measures (i.e., cardiac output and stroke volume) will be evaluated. Measurements will be performed at rest and continuously during the exercise test. These measurements will be performed at each visit. 8. Free-living physical activity: after the baseline visit subjects will be invited to wear a triaxial accelerometer around their waist for 7 days and return it at the end of each intervention 9. Questionnaires: validated questionnaires will be used to assess dietary intake and physical activity | — |
Countries
United Kingdom
Outcome results
None listed