Babateen Abrar M, Rubele Sofia, Shannon Oliver, Okello Edward, Smith Ellen, McMahon Nicholas, O'Brien Gerry, Wightman Emma, Kennedy David, Mathers John C, Siervo Mario
Human Nutrition Research Centre, Population Health Sciences Institute, Newcastle University, Leech Building, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK.
Faculty of Applied Medical Sciences, Clinical Nutrition Department, Umm Al-Qura University, Makkah, Saudi Arabia.
Contemp Clin Trials Commun. 2020 Apr 25;18:100571. doi: 10.1016/j.conctc.2020.100571. eCollection 2020 Jun.
Nitrate-rich food can increase NO production and may induce positive effects on brain function. This study examined the feasibility of a randomized clinical trial (RCT) testing the effects of prolonged consumption of incremental doses of dietary nitrate (NO ) in overweight and obese older participants. Secondary aims tested dose-dependent changes in cognitive, vascular and pulmonary functions and cerebral blood flow (CBF).
This was a single blind, four-arm parallel RCT conducted in 60 overweight and obese older participants. Eligible participants were randomized to:1) high NO (140 ml of beetroot juice (BJ) per day, ~800 mg of NO /day), 2) moderate NO (70 ml of BJ per day, ~400 mg of NO /day), 3) low NO (70 ml on alternate days, ~400 mg of NO ) or 4) NO depleted (70 ml on alternate days, ~0.001 mg of NO). Measurements of cognitive, vascular and pulmonary functions and CBF were conducted at baseline and 13-weeks NO intake was assessed by six 24-h recalls, and by measuring NO intake biomarkers. Feasibility was assessed by obtaining qualitative feedback and evaluating trial recruitment, retention, compliance with study visits and measurement protocols.
Participant recruitment started in July 2018 and ended in April 2019. Of all the recruitment strategies that were used, advertisement of the study via Facebook generated the highest response rate. Sixty-two participants consented and were enrolled. Overall, characteristics of included participants matched our recruitment criteria.
The findings from this study provide evidence of the acceptability and feasibility of an intervention investigating the effects of incremental doses of high-nitrate BJ over a prolonged period.
The intervention study was registered with clinical trial ISRCTN registry (ISRCTN14746723) on 27 December 2018.
富含硝酸盐的食物可增加一氧化氮（NO）的生成，可能对脑功能产生积极影响。本研究探讨了一项随机临床试验（RCT）的可行性，该试验旨在测试超重和肥胖老年参与者长期摄入递增剂量膳食硝酸盐（NO）的效果。次要目标是测试认知、血管和肺功能以及脑血流量（CBF）的剂量依赖性变化。
这是一项在60名超重和肥胖老年参与者中进行的单盲、四臂平行随机对照试验。符合条件的参与者被随机分为：1）高NO组（每天140毫升甜菜根汁（BJ），约800毫克NO/天），2）中NO组（每天70毫升BJ，约400毫克NO/天），3）低NO组（隔天70毫升，约400毫克NO）或4）NO耗尽组（隔天70毫升，约0.001毫克NO）。在基线时进行认知、血管和肺功能以及CBF的测量，通过6次24小时回顾性调查和测量NO摄入生物标志物来评估13周的NO摄入量。通过获取定性反馈以及评估试验招募、保留、对研究访视和测量方案的依从性来评估可行性。
参与者招募于2018年7月开始，2019年4月结束。在所有使用的招募策略中，通过脸书宣传该研究产生的回应率最高。62名参与者同意并被纳入。总体而言，纳入参与者的特征符合我们的招募标准。
本研究结果提供了证据，证明一项长期研究递增剂量高硝酸盐BJ效果的干预措施具有可接受性和可行性。
该干预研究于2018年12月27日在临床试验ISRCTN注册中心（ISRCTN14746723）注册。
