Palmer Suetonia C, Maggo Jasjot K, Campbell Katrina L, Craig Jonathan C, Johnson David W, Sutanto Bernadet, Ruospo Marinella, Tong Allison, Strippoli Giovanni Fm
Department of Medicine, University of Otago Christchurch, 2 Riccarton Ave, PO Box 4345, Christchurch, New Zealand, 8140.
Faculty of Health Science and Medicine, Bond University, 2 Promenthean Way, Robina, Queensland, Australia, 4226.
Cochrane Database Syst Rev. 2017 Apr 23;4(4):CD011998. doi: 10.1002/14651858.CD011998.pub2.
Dietary changes are routinely recommended in people with chronic kidney disease (CKD) on the basis of randomised evidence in the general population and non-randomised studies in CKD that suggest certain healthy eating patterns may prevent cardiovascular events and lower mortality. People who have kidney disease have prioritised dietary modifications as an important treatment uncertainty.
This review evaluated the benefits and harms of dietary interventions among adults with CKD including people with end-stage kidney disease (ESKD) treated with dialysis or kidney transplantation.
We searched the Cochrane Kidney and Transplant Specialised Register (up to 31 January 2017) through contact with the Information Specialist using search terms relevant to this review. Studies contained in the Specialised Register are identified through search strategies specifically designed for CENTRAL, MEDLINE, and EMBASE; handsearching conference proceedings; and searching the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.
Randomised controlled trials (RCTs) or quasi-randomised RCTs of dietary interventions versus other dietary interventions, lifestyle advice, or standard care assessing mortality, cardiovascular events, health-related quality of life, and biochemical, anthropomorphic, and nutritional outcomes among people with CKD.
Two authors independently screened studies for inclusion and extracted data. Results were summarised as risk ratios (RR) for dichotomous outcomes or mean differences (MD) or standardised MD (SMD) for continuous outcomes, with 95% confidence intervals (CI) or in descriptive format when meta-analysis was not possible. Confidence in the evidence was assessed using GRADE.
We included 17 studies involving 1639 people with CKD. Three studies enrolled 341 people treated with dialysis, four studies enrolled 168 kidney transplant recipients, and 10 studies enrolled 1130 people with CKD stages 1 to 5. Eleven studies (900 people) evaluated dietary counselling with or without lifestyle advice and six evaluated dietary patterns (739 people), including one study (191 people) of a carbohydrate-restricted low-iron, polyphenol enriched diet, two studies (181 people) of increased fruit and vegetable intake, two studies (355 people) of a Mediterranean diet and one study (12 people) of a high protein/low carbohydrate diet. Risks of bias in the included studies were generally high or unclear, lowering confidence in the results. Participants were followed up for a median of 12 months (range 1 to 46.8 months).Studies were not designed to examine all-cause mortality or cardiovascular events. In very-low quality evidence, dietary interventions had uncertain effects on all-cause mortality or ESKD. In absolute terms, dietary interventions may prevent one person in every 3000 treated for one year avoiding ESKD, although the certainty in this effect was very low. Across all 17 studies, outcome data for cardiovascular events were sparse. Dietary interventions in low quality evidence were associated with a higher health-related quality of life (2 studies, 119 people: MD in SF-36 score 11.46, 95% CI 7.73 to 15.18; I = 0%). Adverse events were generally not reported.Dietary interventions lowered systolic blood pressure (3 studies, 167 people: MD -9.26 mm Hg, 95% CI -13.48 to -5.04; I = 80%) and diastolic blood pressure (2 studies, 95 people: MD -8.95, 95% CI -10.69 to -7.21; I = 0%) compared to a control diet. Dietary interventions were associated with a higher estimated glomerular filtration rate (eGFR) (5 studies, 219 people: SMD 1.08; 95% CI 0.26 to 1.97; I = 88%) and serum albumin levels (6 studies, 541 people: MD 0.16 g/dL, 95% CI 0.07 to 0.24; I = 26%). A Mediterranean diet lowered serum LDL cholesterol levels (1 study, 40 people: MD -1.00 mmol/L, 95% CI -1.56 to -0.44).
AUTHORS' CONCLUSIONS: Dietary interventions have uncertain effects on mortality, cardiovascular events and ESKD among people with CKD as these outcomes were rarely measured or reported. Dietary interventions may increase health-related quality of life, eGFR, and serum albumin, and lower blood pressure and serum cholesterol levels.Based on stakeholder prioritisation of dietary research in the setting of CKD and preliminary evidence of beneficial effects on risks factors for clinical outcomes, large-scale pragmatic RCTs to test the effects of dietary interventions on patient outcomes are required.
基于普通人群的随机证据以及慢性肾脏病（CKD）患者的非随机研究，通常建议CKD患者进行饮食调整，这些研究表明某些健康的饮食模式可能预防心血管事件并降低死亡率。患有肾脏疾病的患者已将饮食调整作为重要的治疗不确定因素。
本综述评估了CKD成人患者（包括接受透析或肾移植治疗的终末期肾病（ESKD）患者）饮食干预的益处和危害。
我们通过与信息专家联系，使用与本综述相关的检索词，检索了Cochrane肾脏和移植专业注册库（截至2017年1月31日）。专业注册库中包含的研究是通过专门为CENTRAL、MEDLINE和EMBASE设计的检索策略、手工检索会议论文集以及检索国际临床试验注册平台（ICTRP）搜索入口和ClinicalTrials.gov来识别的。
饮食干预与其他饮食干预、生活方式建议或标准护理的随机对照试验（RCT）或半随机RCT，评估CKD患者的死亡率、心血管事件、健康相关生活质量以及生化、人体测量和营养结局。
两位作者独立筛选纳入研究并提取数据。结果以二分结局的风险比（RR）或连续结局的均值差（MD）或标准化均值差（SMD）汇总，并给出95%置信区间（CI）；当无法进行Meta分析时，则以描述性格式呈现。使用GRADE评估证据的可信度。
我们纳入了17项研究，涉及1639例CKD患者。三项研究纳入了341例接受透析治疗的患者，四项研究纳入了168例肾移植受者，十项研究纳入了1130例CKD 1至5期患者。11项研究（共900人）评估了饮食咨询（有或无生活方式建议），6项研究（共739人）评估了饮食模式，其中包括一项关于碳水化合物限制、低铁、富含多酚饮食（191人）的研究，两项关于增加水果和蔬菜摄入量（181人）的研究，两项关于地中海饮食（355人）的研究以及一项关于高蛋白/低碳水化合物饮食（12人）的研究。纳入研究中的偏倚风险普遍较高或不明确，降低了对结果的可信度。参与者的中位随访时间为12个月（范围1至46.8个月）。研究并非旨在检查全因死亡率或心血管事件。在极低质量的证据中，饮食干预对全因死亡率或ESKD的影响不确定。从绝对数值来看，饮食干预可能使每3000名接受一年治疗的患者中避免一人发生ESKD，尽管这种效果的确定性非常低。在所有17项研究中，心血管事件的结局数据稀少。低质量证据中的饮食干预与较高的健康相关生活质量相关（2项研究，119人：SF - 36评分的MD为11.46，95%CI为7.73至15.18；I = 0%）。一般未报告不良事件。与对照饮食相比，饮食干预降低了收缩压（3项研究，167人：MD - 9.26 mmHg，95%CI为 - 13.48至 - 5.04；I = 80%）和舒张压（2项研究，95人：MD - 8.95，95%CI为 - 10.69至 - 7.21；I = 0%）。饮食干预与较高的估计肾小球滤过率（eGFR）相关（5项研究，219人：SMD为1.08；95%CI为0.26至1.97；I = 88%）以及血清白蛋白水平（6项研究，541人：MD为0.16 g/dL，95%CI为0.07至0.24；I = 26%）。地中海饮食降低了血清低密度脂蛋白胆固醇水平（1项研究，40人：MD - 1.00 mmol/L，95%CI为 - 1.56至 - 0.44）。
饮食干预对CKD患者的死亡率、心血管事件和ESKD的影响不确定，因为这些结局很少被测量或报告。饮食干预可能会提高健康相关生活质量、eGFR和血清白蛋白水平，并降低血压和血清胆固醇水平。基于利益相关者对CKD背景下饮食研究的优先排序以及对临床结局危险因素有益作用的初步证据，需要进行大规模的实用性RCT来测试饮食干预对患者结局的影响。
