Charles Perkins Centre, Faculty of Medicine and Health School of Life and Environmental Sciences, School of Mathematics and Statistics, University of Sydney, Sydney, New South Wales, Australia.
Department of Endocrinology, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia.
JAMA Netw Open. 2023 Jul 3;6(7):e2325658. doi: 10.1001/jamanetworkopen.2023.25658.
Plant-based diets are known to improve cardiometabolic risk in the general population, but their effects on people at high risk of cardiovascular diseases (CVDs) remain inconclusive.
To assess the association of vegetarian diets with major cardiometabolic risk factors, including low-density lipoprotein cholesterol (LDL-C), hemoglobin A1c (HbA1c), systolic blood pressure (SBP), and body weight in people with or at high risk of CVDs.
This meta-analysis was registered before the study was conducted. Systematic searches performed included Embase, MEDLINE, CINAHL, and CENTRAL from inception until July 31, 2021.
Eligible randomized clinical trials (RCTs) that delivered vegetarian diets in adults with or at high risk of CVDs and measured LDL-C, HbA1c or SBP were included. Of the 7871 records screened, 29 (0.4%; 20 studies) met inclusion criteria.
Two reviewers independently extracted data including demographics, study design, sample size, and diet description, and performed risk of bias assessment. A random-effects model was used to assess mean changes in LDL-C, HbA1c, SBP, and body weight. The overall certainty of evidence was evaluated using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) tool.
Mean differences between groups in changes (preintervention vs postintervention) of LDL-C, HbA1c, and SBP; secondary outcomes were changes in body weight and energy intake.
Twenty RCTs involving 1878 participants (range of mean age, 28-64 years) were included, and mean duration of intervention was 25.4 weeks (range, 2 to 24 months). Four studies targeted people with CVDs, 7 focused on diabetes, and 9 included people with at least 2 CVD risk factors. Overall, relative to all comparison diets, meta-analyses showed that consuming vegetarian diets for an average of 6 months was associated with decreased LDL-C, HbA1c, and body weight by 6.6 mg/dL (95% CI, -10.1 to -3.1), 0.24% (95% CI, -0.40 to -0.07), and 3.4 kg (95% CI, -4.9 to -2.0), respectively, but the association with SBP was not significant (-0.1 mm Hg; 95% CI, -2.8 to 2.6). The GRADE assessment showed a moderate level of evidence for LDL-C and HbA1c reduction.
In this study, consuming a vegetarian diet was associated with significant improvements in LDL-C, HbA1c and body weight beyond standard therapy in individuals at high risk of CVDs. Additional high-quality trials are warranted to further elucidate the effects of healthy plant-based diets in people with CVDs.
植物性饮食已被证实可改善普通人群的心血管代谢风险，但它们对心血管疾病（CVD）高危人群的影响仍不确定。
评估素食饮食与主要心血管代谢风险因素的关联，包括低密度脂蛋白胆固醇（LDL-C）、糖化血红蛋白（HbA1c）、收缩压（SBP）和体重，这些因素在患有或有 CVD 风险的人群中。
本荟萃分析在研究进行前已注册。系统检索包括 Embase、MEDLINE、CINAHL 和 CENTRAL，从成立到 2021 年 7 月 31 日。
纳入了在患有或有 CVD 风险的成年人中提供素食饮食的随机临床试验（RCT），并测量 LDL-C、HbA1c 或 SBP。在筛选出的 7871 条记录中，有 29 条（0.4%；20 项研究）符合纳入标准。
两位评审员独立提取数据，包括人口统计学、研究设计、样本量和饮食描述，并进行了偏倚风险评估。使用随机效应模型评估 LDL-C、HbA1c、SBP 和体重变化的平均值。使用推荐评估、制定与评估（GRADE）工具评估证据的总体确定性。
组间（干预前与干预后） LDL-C、HbA1c 和 SBP 变化的平均值差异；次要结果是体重和能量摄入的变化。
纳入了 20 项 RCT，涉及 1878 名参与者（平均年龄范围为 28-64 岁），干预平均持续时间为 25.4 周（范围为 2 至 24 个月）。四项研究针对 CVD 患者，七项研究针对糖尿病患者，九项研究包括至少有 2 项 CVD 风险因素的患者。总体而言，与所有对照饮食相比，荟萃分析表明，平均食用素食饮食 6 个月可使 LDL-C、HbA1c 和体重分别降低 6.6mg/dL（95%CI，-10.1 至-3.1）、0.24%（95%CI，-0.40 至-0.07）和 3.4kg（95%CI，-4.9 至-2.0），但 SBP 无显著变化（-0.1mmHg；95%CI，-2.8 至 2.6）。GRADE 评估显示，LDL-C 和 HbA1c 降低的证据质量为中等水平。
在这项研究中，与标准治疗相比，高心血管疾病风险人群食用素食饮食可显著改善 LDL-C、HbA1c 和体重。需要进行更多高质量的试验来进一步阐明健康植物性饮食对 CVD 患者的影响。
