Research Centre of Applied and Preventive Cardiovascular Medicine, University of Turku, Turku, Finland.
Department of Clinical Physiology and Nuclear Medicine, University of Turku and Turku University Hospital, P.O. Box 52, FI-20521, Turku, Finland.
Nutr J. 2017 Oct 27;16(1):73. doi: 10.1186/s12937-017-0291-0.
The primary aim of this study was to test the hypothesis that an orally ingested apple polyphenol extract rich in epicatechin and flavan-3-ol oligomers improves endothelium-dependent brachial artery flow-mediated vasodilatation (FMD) in volunteers with borderline hypertension. The secondary aim of the study was to test whether the investigational product would improve endothelium-independent nitrate-mediated vasodilatation (NMD).
This was a single centre, repeated-dose, double-blind, placebo-controlled, crossover study in 60 otherwise healthy subjects (26 men, 34 women; aged 40-65 years) with borderline hypertension (blood pressure 130-139/85-89 mmHg) or unmedicated mild hypertension (blood pressure 140-165/90-95 mmHg). The subjects were randomised to receive placebo or the apple polyphenol extract to provide a daily dose of 100 mg epicatechin for 4 weeks, followed by a four to five-week wash-out period, and then 4 weeks intake of the product that they did not receive during the first treatment period. FMD and NMD of the left brachial artery were investigated with ultrasonography at the start and end of both treatment periods, and the per cent increase of the arterial diameter (FMD% and NMD%) was calculated.
With the apple extract treatment, a significant acute improvement was detected in the mean change of maximum FMD% at the first visit 1.16 (p = 0.04, 95% CI: 0.04; 2.28), last visit 1.37 (p = 0.02, 95% CI: 0.22; 2.52) and for both visits combined 1.29 (p < 0.01, 95% CI: 0.40; 2.18). However, such improvement was not statistically significant when apple extract was compared with placebo. The overall long-term effect of apple extract on FMD% was not different from placebo. No statistically significant differences between the apple extract and placebo treatments were observed for endothelium-independent NMD.
A significant acute improvement in maximum FMD% with apple extract administration was found. However, superiority of apple extract over placebo was not statistically significant in our study subjects with borderline hypertension or mild hypertension. The study raised no safety concerns regarding the daily administration of an apple polyphenol extract rich in epicatechin.
The trial is registered at http://clinicaltrials.gov (identifier: NCT01690676 ). Registered 25th May 2012.
本研究的主要目的是检验口服富含表儿茶素和黄烷-3-醇低聚物的苹果多酚提取物可改善边缘性高血压志愿者的内皮依赖性肱动脉血流介导的舒张功能（FMD）这一假说。该研究的次要目的是检验该受试物是否可改善内皮非依赖性硝酸盐介导的血管舒张功能（NMD）。
这是一项单中心、重复剂量、双盲、安慰剂对照、交叉研究，共纳入 60 名健康志愿者（26 名男性，34 名女性；年龄 40-65 岁），他们患有边缘性高血压（血压 130-139/85-89mmHg）或未经药物治疗的轻度高血压（血压 140-165/90-95mmHg）。将受试者随机分为安慰剂组或苹果多酚提取物组，每日摄入 100mg 表儿茶素，持续 4 周，然后进行 4-5 周洗脱期，再摄入他们在前一治疗期未摄入的产品 4 周。在两个治疗期的开始和结束时，通过超声检查左肱动脉的 FMD 和 NMD，计算动脉直径的百分比变化（FMD%和 NMD%）。
在苹果提取物治疗组中，第一次就诊时最大 FMD%的平均变化有显著的急性改善，为 1.16（p=0.04，95%CI：0.04；2.28），最后一次就诊时为 1.37（p=0.02，95%CI：0.22；2.52），两次就诊时的总和为 1.29（p<0.01，95%CI：0.40；2.18）。然而，与安慰剂相比，这种改善并不具有统计学意义。与安慰剂相比，苹果提取物对 FMD%的长期总体影响无差异。在边缘性高血压或轻度高血压患者中，苹果提取物与安慰剂治疗之间未见内皮非依赖性 NMD 的统计学差异。
在给予苹果提取物后，FMD%的最大急性改善明显。然而，在本研究的边缘性高血压或轻度高血压受试者中，苹果提取物与安慰剂相比，不具有统计学优势。该研究未发现每日给予富含表儿茶素的苹果多酚提取物的安全性问题。
该试验在 http://clinicaltrials.gov 注册（标识符：NCT01690676）。于 2012 年 5 月 25 日注册。
