Effects of grape powder supplementation on inflammatory and antioxidant markers in hemodialysis patients: A randomized double-blind study

Introduction: Polyphenols contained in natural sources such as grapes, have been considered pharmacological agents to combat oxidative stress and inflammation, common features in Chronic Kidney Disease patients. Objective: To evaluate the effects of grape powder supplementation on inflammatory and antioxidant biomarkers in hemodialysis (HD) patients. Methods: The double-blind placebo-controlled randomized clinical trial evaluated non-diabetic HD patients that received grape powder (500 mg of polyphenols/day) (n = 16, 9 men, 53.0 ± 9.8 years of age, 111.6 ± 58.2 HD months) or placebo (n = 16, 9 men, 52.7 ± 13.7 years of age, 110.4 ± 93.1 HD months) for five weeks. The glutathione peroxidase (GSH-Px) activity and C-reactive protein (CRP) levels were evaluated by ELISA method. Results: After the intervention period, the patients receiving grape powder showed an increase in the GSH-Px activity (16.5 (41.0) to 42.0 (43.3) nmol/min/ml) (p < 0.05) and they did not have the CRP levels increased as seen in placebo group (2.6 (0.28) to 2.8 (0.23 mg/L) (p < 0.05). Conclusion: The use of grape powder as phenolic source could play an important role as an antioxidant and anti-inflammatory agent in non-diabetic HD patients.引言：存在于葡萄等天然来源中的多酚类物质，已被视为可对抗氧化应激与炎症的药理学制剂，而氧化应激与炎症均为慢性肾脏病（Chronic Kidney Disease）患者的常见病理特征。 研究目的：评估葡萄粉补充剂对血液透析（hemodialysis, HD）患者炎症与抗氧化生物标志物的影响。 研究方法：本项双盲安慰剂对照随机临床试验纳入非糖尿病血液透析患者，将其随机分为两组：葡萄粉补充组（每日摄入500mg多酚，n=16，含9名男性，年龄53.0±9.8岁，血液透析病程111.6±58.2个月）与安慰剂组（n=16，含9名男性，年龄52.7±13.7岁，血液透析病程110.4±93.1个月），两组均接受为期5周的干预。本研究采用酶联免疫吸附测定（ELISA）法检测谷胱甘肽过氧化物酶（glutathione peroxidase, GSH-Px）活性与C反应蛋白（C-reactive protein, CRP）水平。 研究结果：干预周期结束后，摄入葡萄粉的患者其谷胱甘肽过氧化物酶活性显著提升[从16.5(41.0)升至42.0(43.3) nmol/min/ml，p<0.05]；且与安慰剂组（C反应蛋白水平从2.6(0.28)升至2.8(0.23) mg/L，p<0.05）不同，该组患者的C反应蛋白水平未出现升高。 研究结论：以葡萄粉作为多酚来源，或可在非糖尿病血液透析患者中发挥重要的抗氧化与抗炎作用。