Dose-response Effect of Dietary Nitrate on Muscle Function in Older Individuals
Ключови думи
Резюме
Описание
This study consists of four visits that will take a minimum of 15 days to complete.
Study Visit One (Screening) 1-2 hours The purpose of the screening visit is to explain all aspects of the study. The investigators will also determine if individuals can participate in the study. Eligible subjects will undergo a complete medical history and physical exam. They will have their blood drawn, and will provide a urine sample (to determine if they are pregnant). Subjects will also practice the entire neuromuscular function exercise test. During this test, the strength of the subject's muscles will be determined by having them kick, push and/or pull back as hard as they can while their leg is strapped to an exercise device. Blood pressure and heart rate and rhythm will be monitored.
Subjects will be instructed to consume their normal diet throughout the study. However, they will be asked to avoid eating foods high in nitrate such as beets, spinach, and collard greens the evening before each visit. They will be asked to refrain from the use of antibacterial mouthwash, such as Listerine or Cepacol, during the study. Subjects will also be asked to not chew gum or to consume alcohol or food and drinks that contain caffeine for 24 hour before each visit. This includes coffee, tea, chocolate and soft drinks such as Mountain Dew. Finally, they will be asked to fast for 12 hour prior to each study visit.
Study Visit Two - Approximately 5 hours At the beginning of this visit a catheter (small, flexible, sterile plastic tube) will be placed through a vein in one of the subject's arms. This is for collection of blood samples. Blood will be drawn four times during this visit. Each draw will be 6mL or about 1.2 teaspoons. The first blood draw will check nitrate and nitrogen levels. Subjects will then have a breath test to check nitric oxide. They will then drink about 280 mL (about 1 cup) of BRJ. In one trial, this will be a placebo, that is, BRJ from which the essentially all of the nitrate has been removed. In another trial, they will drink BRJ still containing nitrate. In a third trial, they will drink an equal mixture of the placebo and nitrate-containing BRJ. Blood and breath samples will be obtained every hour. Heart rate and blood pressure will be measured at the same times the blood and breath samples are obtained. About 2 hours after ingestion of BRJ (or placebo) subjects will be asked to perform the neuromuscular function test that was practiced during the screening visit. After completing the exercise test one final blood and breath sample will be obtained.
Study Visits Three and Four
The same procedures completed during Study Visit Two will be performed. The order of treatment (placebo vs. lower dose vs. higher dose of nitrate) will be randomized using a computer program. Neither the subjects nor the investigators will know the treatment they receive during each visit until the entire study is completed.
Дати
Последна проверка: | 03/31/2020 |
Първо изпратено: | 07/10/2018 |
Очаквано записване подадено: | 07/10/2018 |
Първо публикувано: | 07/22/2018 |
Изпратена последна актуализация: | 04/16/2020 |
Последна актуализация публикувана: | 04/20/2020 |
Действителна начална дата на проучването: | 08/31/2018 |
Приблизителна дата на първично завършване: | 07/30/2020 |
Очаквана дата на завършване на проучването: | 07/30/2020 |
Състояние или заболяване
Интервенция / лечение
Dietary Supplement: Beet root juice
Фаза
Групи за ръце
Arm | Интервенция / лечение |
---|---|
Placebo Comparator: Placebo 3.3 mL/kg concentrated beet root juice *depleted of nitrate* Other names: Beet It Sport Nitrate 400 placebo | |
Active Comparator: low nitrate 1.55 mL/kg concentrated beet root juice depleted of nitrate + 1.55 mL/kg concentrated beet root juice *depleted of nitrate*
Other names: Beet It Sport Nitrate 400 placebo + Beet It Sport Nitrate 400 | |
Active Comparator: high nitrate 3.3 mL/kg concentrated beet root juice containing nitrate
Other names:Beet It Sport Nitrate 400 |
Критерии за допустимост
Възрасти, отговарящи на условията за проучване | 65 Years Да се 65 Years |
Полове, допустими за проучване | All |
Приема здрави доброволци | Да |
Критерии | Inclusion Criteria: • In good health, as determined by the investigator's review of history (provided by subject at screening visit), physical examination, and routine blood and urine tests (done at screening visit) Exclusion Criteria: - Men and women <65 or >79 years of age - Unable to provide informed consent - Currently pregnant or lactating (given the age range for the study, verbal confirmation by subject is believed to be sufficient) - Current smokers - Significant orthopedic limitations or other contraindications to strenuous exercise - Those taking phosphodiesterase inhibitors (e.g., Viagra) - Those taking proton pump inhibitors, antacids, xanthine oxidase inhibitors, or on hormone replacement therapy - Those taking anti-coagulants (e.g., Coumadin) or on anti-platelet therapy - History of neuromuscular disease (e.g., cervical spondylotic radiculomyelpathy, lumbar spondylosis, amyotrophic lateral sclerosis, Guillain-Barré syndrome, and acquired demyelinating polyneuropathies), cardiovascular disease (e.g., > stage I hypertension, heart failure, myocardial infarction/ischemia, significant myocardial or pericardial diseases (e.g. amyloidosis, constriction), moderate or severe valvular disease, renal disease, liver disease, or anemia |
Резултат
Първични изходни мерки
1. Muscle function [1 day]
Други изходни мерки
1. Plasma nitrate [0, 1, 2 3 hours after treatment]
2. Plasma nitrite [0, 1, 2 3 hours after treatment]
3. Breath nitric oxide [0, 1, 2 3 hours after treatment]