低碳水化合物飲食可安全有效地緩解2型糖尿病
作者：
小柯機器人發布時間：2021/1/17 16:13:00
美國德克薩斯農工大學Bradley C Johnston團隊研究了低碳水化合物和極低碳水化合物飲食對2型糖尿病緩解的療效和安全性。2021年1月13日，該研究發表在《英國醫學雜誌》上。
為了確定低碳水化合物飲食（LCD）和極低碳水化合物飲食（VLCD）對2型糖尿病患者的療效和安全性，研究組對CENTRAL、Medline、Embase等大型資料庫中從成立到2020年8月25日的文獻進行檢索，篩選出評估2型糖尿病成人至少12周LCD和VLCD幹預的隨機臨床試驗，並進行系統審查和薈萃分析。主要結局是糖尿病的緩解（HbA1c<6.5％或空腹血糖<7.0 mmol / L，無論是否服用糖尿病藥物）、體重減輕、HbA1c、空腹血糖和不良事件。次要結局包括與健康相關的生活質量和生化實驗室數據。
研究組共檢索了14759篇引文，共納入23項試驗（1357名參與者），40.6%的結果被判定為低偏倚風險。在6個月時，與對照飲食相比，LCD的糖尿病緩解率更高（定義為HbA1c<6.5%）。相反，當使用HbA1c<6.5%且不服藥的緩解定義時，緩解率有較小但不顯著的提高。確定為符合可信度標準的亞組評估表明，在包括使用胰島素的患者的研究中，LCD的緩解率明顯降低。
在12個月時，關於病情緩解的數據很少，從輕微改善到輕微的糖尿病風險增加不等。在6個月時，體重減輕、甘油三酯和胰島素敏感性均有顯著的臨床意義改善，12個月時改善程度有所下降。根據可信的分組評估，VLCD在6個月時的減重效果不如限制性較小的LCD。然而，這種影響可以通過堅持飲食來解釋。也就是說，與使用VLCD的依從性較差的患者相比，使用LCD的依從性較好的患者其體重在臨床上顯著降低。參與者6個月時的生活質量沒有顯著差異，但在12個月時生活質量和低密度脂蛋白膽固醇惡化方面具有臨床上重要但無統計學意義的差異。另外，在6個月和12個月時，在不良事件或血脂方面，未發現兩組間有顯著或臨床意義的差異。
總之，根據中低確定性的證據，堅持使用LCD 6個月的糖尿病患者病情有望緩解，而不會產生不良後果。
附：英文原文
Title: Efficacy and safety of low and very low carbohydrate diets for type 2 diabetes remission: systematic review and meta-analysis of published and unpublished randomized trial data
Author: Joshua Z Goldenberg, Andrew Day, Grant D Brinkworth, Junko Sato, Satoru Yamada, Tommy Jnsson, Jennifer Beardsley, Jeffrey A Johnson, Lehana Thabane, Bradley C Johnston
Issue&Volume: 2021/01/13
Abstract:
Objective To determine the efficacy and safety of low carbohydrate diets (LCDs) and very low carbohydrate diets (VLCDs) for people with type 2 diabetes.
Design Systematic review and meta-analysis.
Data sources Searches of CENTRAL, Medline, Embase, CINAHL, CAB, and grey literature sources from inception to 25 August 2020.
Study selection Randomized clinical trials evaluating LCDs (<130 g/day or <26% of a 2000 kcal/day diet) and VLCDs (<10% calories from carbohydrates) for at least 12 weeks in adults with type 2 diabetes were eligible.
Data extraction Primary outcomes were remission of diabetes (HbA1c <6.5% or fasting glucose <7.0 mmol/L, with or without the use of diabetes medication), weight loss, HbA1c, fasting glucose, and adverse events. Secondary outcomes included health related quality of life and biochemical laboratory data. All articles and outcomes were independently screened, extracted, and assessed for risk of bias and GRADE certainty of evidence at six and 12 month follow-up. Risk estimates and 95% confidence intervals were calculated using random effects meta-analysis. Outcomes were assessed according to a priori determined minimal important differences to determine clinical importance, and heterogeneity was investigated on the basis of risk of bias and seven a priori subgroups. Any subgroup effects with a statistically significant test of interaction were subjected to a five point credibility checklist.
Results Searches identified 14759 citations yielding 23 trials (1357 participants), and 40.6% of outcomes were judged to be at low risk of bias. At six months, compared with control diets, LCDs achieved higher rates of diabetes remission (defined as HbA1c <6.5%) (76/133 (57%) v 41/131 (31%); risk difference 0.32, 95% confidence interval 0.17 to 0.47; 8 studies, n=264, I2=58%). Conversely, smaller, non-significant effect sizes occurred when a remission definition of HbA1c <6.5% without medication was used. Subgroup assessments determined as meeting credibility criteria indicated that remission with LCDs markedly decreased in studies that included patients using insulin. At 12 months, data on remission were sparse, ranging from a small effect to a trivial increased risk of diabetes. Large clinically important improvements were seen in weight loss, triglycerides, and insulin sensitivity at six months, which diminished at 12 months. On the basis of subgroup assessments deemed credible, VLCDs were less effective than less restrictive LCDs for weight loss at six months. However, this effect was explained by diet adherence. That is, among highly adherent patients on VLCDs, a clinically important reduction in weight was seen compared with studies with less adherent patients on VLCDs. Participants experienced no significant difference in quality of life at six months but did experience clinically important, but not statistically significant, worsening of quality of life and low density lipoprotein cholesterol at 12 months. Otherwise, no significant or clinically important between group differences were found in terms of adverse events or blood lipids at six and 12 months.
Conclusions On the basis of moderate to low certainty evidence, patients adhering to an LCD for six months may experience remission of diabetes without adverse consequences. Limitations include continued debate around what constitutes remission of diabetes, as well as the efficacy, safety, and dietary satisfaction of longer term LCDs.
DOI: 10.1136/bmj.m4743
Source: https://www.bmj.com/content/372/bmj.m4743