植物甾醇降脂机制和效果的系统综述及Meta分析

Low density lipoprotein-cholesterol lowering mechanism and blood lipid profile managing effect of phy- tosterol in healthy normal and hypercholesterolemia： a meta-analysis of randomly controlled trials

目的探讨植物甾醇降低血清低密度脂蛋白胆固醇水平的可能机制及其强化膳食及补充剂的临床降脂效果。方法进行植物甾醇降脂机制相关基础实验研究的综述及植物甾醇强化膳食临床降脂效果相关随机对照研究的Meta分析。计算机检索2007年1月至2017年1月PubMed、EMBASE、CochraneLibrary等数据库中植物甾醇降脂机制及临床降脂效果的文献，同时进行手工检索及参考文献回溯。根据纳入及排除标准严格筛选检索所得文献。对所纳入的降脂效果相关临床随机对照研究，采用Cochrane偏倚风险评估工具进行偏倚风险评价。并采用RevMan5．3软件进行Meta分析，研究植物甾醇强化膳食及补充剂对健康人群及高脂血症者血清低密度脂蛋白胆固醇、高密度脂蛋白胆固醇及三酰甘油水平的影响。结果通过全面检索及严格筛选共纳入文献58篇，其中降脂机制相关文献46篇、降脂效果相关文献12篇，涉及872例受试者。Meta分析结果显示，植物甾醇强化膳食及补充剂可降低健康人群及高脂血症者血清低密度脂蛋白胆固醇水平（MD=-0．24，95％CI=-0．31—0．16，P〈0．00001），对高密度脂蛋白胆固醇水平（MD=0．04，95％CI=-0．01～0．08，P=0．12）及三酰甘油水平（MD=0．05，95％CI=-0．04-0．13，P=0．30）无影响。结论植物甾醇强化膳食可在不影响高密度脂蛋白胆固醇及三酰甘油水平的情况下降低健康人群及高脂血症者血清低密度脂蛋白胆固醇水平，竞争性抑制胆固醇进入胶柬是植物甾醇降低血清低密度脂蛋白胆固醇水平的主要但不是唯一确定性机制。

Objective To investigate the possible mechanism of phytosterol reducing low density lipo- protein cholesterol （LDL-C） in the serum, and evaluate the clinical effect of phytosterol-enriched functional food and dietary supplement on blood lipid profile. Methods We systematically reviewed the literature on the mechanism of phytosterol reducing LDL-C in the serum, and conducted a meta-analysis of randomly controlled trials （RCT） on the clinical effect of phytosterol-enriched functional food and dietary supplement on blood lip- id profile. We searched in databases, including PubMed, EMBASE and Cochrane Library, for literature in the timeframe between January 2007 and January 2017, and conducted manual searching and reference re- view. Researches were strictly screened based on predetermined inclusion and exclusion criteria, and RCTs included in the meta-analysis were tested using the Cochrane Collaboration＇s tool for assessing risk of bias. The meta-analysis was conducted with RevMan 5.3 to investigate the effects of phytosterol-enriched functional food and dietary supplement on the levels of LDL-C, high density lipoprotein cholesterol （HDL-C） and triglyceride （TG） in the serum of health population and patients with hyperchotesterolemia. Results A total of 58 resear- ches were included, of which 46 were related to the cholesterol lowering mechanism of phytosterol and 12 were RCTs on its cholesterol lowering effect. The meta-analysis involved 872 subjects and showed that, in bothhealthy population and patients with hypercholesteromia, phytosterol-enriched foods and supplements could reduce serum LDL-C level （MD=-0. 24, 95% CI=-0. 31-0.16, P〈0. 000 0l） but not HDL-C （MD= 0.04, 95% CI=-0.01-0.08, P=0. 12） orTG level （MD=O. 05, 95% CI=-0.04-0. 13, P=0.30）. Conclusions Phytosterol-enriched foods and supplements could reduce serum LDL-C level without affecting HDL-C and TG level in both healthy population and patients with hypercholesteromia. Competitive inhibition of cholesterol from entering micelle is one of the established mechanisms behind the LDL-C lowering effect of phytosterol.