Effect of beetroot juice and handgrip training on blood pressure in older adults who are overweight or obese Nutritional, Metabolic, Endocrine
Conditions
Interventions
Random allocation (beetroot juice, handgrip strength or control).
1. A low nitrate diet plus beetroot juice consumption for 7 days
2. A low nitrate diet plus handgrip t
however, they are recommended to avoid high nitrate foods for which they receive advice on what to avoid. The energy content of the beetroot juice is 173 kcal. The interventions lasts for 7 days.
Sponsors
Newcastle University (UK)
Eligibility
Sex/Gender
All
Inclusion criteria
Inclusion criteria: 1. Healthy (with no established diagnosis) 2. Non-smoking men and women aged 55-70 years with a body mass index (BMI) in the range of 25-40 kg/m2.
Exclusion criteria
Exclusion criteria: 1. Current participation in other clinical investigations. 2. Physical disabilities, trauma or surgery which limit mobility and impede physical performance (i.e. not able to comply with the isometric exercise intervention). 3. Vegetarianism (likely to have very high nitrate intake). 4. Aversion to beetroot consumption or inability to comply with the study diet (lack of compliance). 5. High physical activity level (may have BMI in obese range but low fat mass). 6. Weight change more than 3.0 kg in the last 2 months (important influence on systemic metabolism and vascular function). 7. Active cancer and any diagnosis of malignant cancer in the last 5 years (systemic effects on study outcomes). 8. Chronic and acute metabolic and inflammatory conditions interfering with the study outcome (systemic effects on study outcomes). For example, severe hypertension (>180 mmHg/>110), kidney stones, gallstones, skin rashes or rheumatoid arthritis. 9. Previous diagnosis of type 1 or type 2 diabetes treated with insulin and oral hypoglycaemic agents (modification of regulation of intermediate metabolism). 10. Weight loss medications (sibutramine, orlistat, rimonabant) and history of bariatric surgery (weight loss related changes in systemic metabolism). 11. Drugs: corticosteroids, sildenafil, diuretics, laxatives, anticoagulants, antacids, nitrate-derived agents, anti-cholinergic, anti-hypertensive (beta-blockers, calcium antagonists, ACE inhibitors and angiotensin receptor inhibitors) (all drugs have either an effect on NO production or insulin sensitivity via different mechanisms). 12. Subjects on hormonal therapies (oestrogens, thyroxine, progesteron), statins and any other anti-dyslipidaemic agent and psychiatric drugs (antidepressants, sedatives, antipsychotics) will be excluded if dose has been started/changed in the previous six months (make sure that these disorders are under strict control to avoid interference with the study outcomes) 13. Haematological disorders including severe anaemia (Hb 21 units/week for men and >14 units/week for women 16. Non English speakers or volunteers requiring translators or interpreters (since these services are not available for this study)
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| 1. 24-hour blood pressure 2. Endothelial function The outcome measures will be evaluated at days 0 and 8 (i.e. before and after 7 days intervention). The primary outcome measure is ambulatory 24-hour blood pressure, which will be evaluated on days 0 and 8. | — |
Secondary
| Measure | Time frame |
|---|---|
| 1. To compare the effects of handgrip training and beetroot juice on muscle strength 2. To assess the association between arterial health, body fat and memory performance 3. To test the relationship between handgrip training and beetroot juice with clinical risk factors for diabetes (insulin, glucose) and high blood pressure Arterial distensibility, which will be undertaken in a temperature-controlled measurement room (~23 ± 1 degrees Celsius). Each subject will be invited to lie supine for a 5-min rest period. Optical probes will then be attached to the right index ?ngertip and right earlobe, and a long cuff will be wrapped around the whole right arm. Single-lead ECG will be also recorded simultaneously. All the measurements will be performed by an experienced operator. A series of ?ve separate measurements will be performed with different external cuff pressures (0, 10, 20, 30 and 40 mmHg) applied to the whole right arm through the long cuff, with a minute rest interval between each measurement. During the recording session, the arms will be kept parallel to the body and as still as possible, with regular and gentle breathing. The measurement will last approximately 30 minutes (Zheng D, Murray A. Peripheral arterial volume distensibility: Significant differences with age and blood pressure measured using an applied external pressure. Physiol Meas. 2011;32:499-512). Handgrip strength: handgrip strength will be assessed in both arms at baseline and after the intervention to measure the maximum isometric strength of the hand and forearm muscles. A lightweight and portable dynamometer will be used. The researcher will follow a specific protocol for the measurement of handgrip strength (i.e. allowing one practice trial, and then record the best of three attempts with 30 seconds rest between each of these). | — |
Countries
United Kingdom
Outcome results
None listed