Low glycaemic index, or low glycaemic load, diets for diabetes mellitus

 

Abstract

Background

The aim of diabetes management is to normalise blood glucose levels, since improved blood glucose control is associated with reduction in development, and progression, of complications. Nutritional factors affect blood glucose levels, however there is currently no universal approach to the optimal dietary treatment for diabetes. There is controversy about how useful the glycaemic index (GI) is in diabetic meal planning. Improved glycaemic control through diet could minimise medications, lessen risk of diabetic complications, improve quality of life and increase life expectancy.

Objectives

To assess the effects of low glycaemic index, or low glycaemic load, diets on glycaemic control in people with diabetes.

Search methods

We performed electronic searches of The Cochrane Library, MEDLINE, EMBASE and CINAHL with no language restriction.

Selection criteria

We assessed randomised controlled trials of four weeks or longer that compared a low glycaemic index, or low glycaemic load, diet with a higher glycaemic index, or load, or other diet for people with either type 1 or 2 diabetes mellitus, whose diabetes was not already optimally controlled.

Data collection and analysis

Two reviewers independently extracted data on study population, intervention and outcomes for each included study, using standardised data extraction forms.

Main results

Eleven relevant randomised controlled trials involving 402 participants were identified. There was a significant decrease in the glycated haemoglobin A1c (HbA1c) parallel group of trials, the weighted mean difference (WMD) was  -0.5% with a 95% confidence interval (CI) of - 0.9 to -0.1, P = 0.02; and in the cross-over group of trials the WMD was -0.5% with a 95% CI of -1.0 to -0.1, P = 0.03. Episodes of hypoglycaemia were significantly fewer with low compared to high GI diet in one trial (difference of -0.8 episodes per patient per month, P < 0.01), and proportion of participants reporting more than 15 hyperglycaemic episodes per month was lower for low-GI diet compared to measured carbohydrate exchange diet in another study (35% versus 66%, P = 0.006). No study reported on mortality, morbidity or costs.

Authors' conclusions

A low-GI diet can improve glycaemic control in diabetes without compromising hypoglycaemic events.

 

Plain language summary

Low glycaemic index, or low glycaemic load, diets for diabetes mellitus

Nutritional factors affect blood glucose levels, however there is currently no universal approach to the optimal dietary strategy for diabetes. Different carbohydrate foods have different effects on blood glucose and can be ranked by the overall effect on the blood glucose levels using the so-called glycaemic index. By contributing a gradual supply of glucose to the bloodstream and hence stimulating lower insulin release, low glycaemic index foods, such as lentils, beans and oats, may contribute to improved glycaemic control, compared to high glycaemic index foods, such as white bread. The so-called glycaemic load represents the overall glycaemic effect of the diet and is calculated by multiplying the glycaemic index by the grammes of carbohydrates.

We identified eleven relevant randomised controlled trials, lasting 1 to 12 months, involving 402 participants. Metabolic control (measured by glycated haemoglobin A1c (HbA1c), a long-term measure of blood glucose levels) decreased by 0.5% HbA1c with low glycaemic index diet, which is both statistically and clinically significant. Hypoglycaemic episodes significantly decreased with low glycaemic index diet compared to high glycaemic index diet. No study reported on mortality, morbidity or costs.

 

摘要

背景

低升糖指數，或低糖負荷飲食對於糖尿病的影響

血糖控制到正常範圍在糖尿病的治療上是重要的一環，因改善血糖可減少並延緩糖尿病併發症。食物的種類會影響到血糖的變化，但目前全球仍缺乏一套最合適的糖尿病飲食治療方式。目前對於升糖指數在糖尿病飲食控制上的幫助程度，仍有許多爭論。利用飲食控制血糖可減少藥物的需求、減少糖尿病併發症、改善生活品質、延長壽命。

目標

評估低升糖指數或低糖負荷飲食，對糖尿病患的血糖控制效果。

搜尋策略

在考科藍圖書館、MEDLINE、EMBASE以及CINAHI上搜尋各種語言的文章。

選擇標準

我們評估進行了大於等於四週的隨機分配對照研究，針對未達理想控制的第1型或第2型糖尿病病患，比較低升糖指數，低糖負荷飲食以及高升糖指數，高糖負荷或其他飲食的差別。

資料收集與分析

2位獨立的評論者，利用標準的擷錄表單，從各收錄的研究中擷取研究族群、介入方式和研究結果的資料。

主要結論

總共分析了11組隨機控制研究、包括402位病患。在飲食控制組，糖化血色素(HbA1c)有顯著的下降，加權平均差異(weighted mean difference)為 −0.5%，95%信賴區間(CI)為 −0.9到 −0.1(p = 0.02); 在組間比較中, 加權平均差異為 −0.5%,95%信賴區間為 −1.0到 −0.1(p = 0.03)。在低升糖指數飲食組中，低血糖的次數明顯比高升糖指數飲食組更低(每人每月減少0.8次低血糖次數， p<0.01)。以每月超過15次低血糖的比率來看，低升糖指數飲食組較測量碳水化合物換算飲食法(measured carbohydrate exchange die)的組別來得低(35%比66%，p = 0.006)。並無有關死亡、殘疾和花費的報告。

作者結論

低升糖指數飲食對糖尿病可以改善血糖，且不會增加低血糖之風險。

翻譯人

本摘要由臺灣大學附設醫院張然舜翻譯。

此翻譯計畫由臺灣國家衛生研究院(National Health Research Institutes, Taiwan)統籌。

總結

食物的種類會影響到血糖的變化，但目前全球仍缺乏一套最合適的糖尿病飲食治療方式。不同的碳水化合物食物對於血糖上升的影響程度不同，這種上升的程度就稱作升糖指數。 低升糖指數食物，像是扁豆、豆子、以及燕麥，釋放糖分到血液中的速度較平緩，因此可減少刺激胰島素釋放的程度。 如此一來，就比高升糖指數食物像是麵包，提供更好的血糖控制。 若把升糖指數乘以碳水化合物的克數，則可算出糖負荷,這代表了飲食對糖分變化的總影響效果。 我們分析了11組進行了1到12個月的隨機對照試驗，包括了402位病患。在使用低升糖指數飲食組，糖化血色素下降了0.5%，且低血糖發生的次數也明顯低於高升糖指數飲食組。各研究對死亡、殘疾以及花費之差異並無報告。