Sport, Health and Performance Enhancement (SHAPE) Research Centre, Musculoskeletal Physiology Research Group, School of Science and Technology, Nottingham Trent University, Nottingham, UK.
Research Centre for Life and Sport Sciences (CLaSS), School of Health and Life Sciences, Department of Sport and Exercise, Birmingham City University, Birmingham, UK.
Syst Rev. 2020 Dec 5;9(1):282. doi: 10.1186/s13643-020-01539-8.
Diabetes is a major public health issue and there is a need to develop low-cost, novel interventions to prevent or reduce disease progression. Growing evidence shows that supplementation with carnosine, or its rate-limiting precursor β-alanine, can ameliorate aspects of the metabolic dysregulation that occurs in diabetes. There is, however, a need to develop a better understanding of the magnitude of effect and the factors associated with positive outcomes. The purpose of this systematic review and meta-analysis is to evaluate the effect of carnosine or β-alanine supplementation on markers of glycaemic control and insulin resistance in humans and animals.
We will perform a systematic search for randomised and non-randomised controlled trials. Studies will be retrieved by searching electronic databases, clinical trial registers, author review, and cross-referencing. Primary outcomes include changes in (i) fasting glucose, (ii) glycated haemoglobin, and (iii) 2-h glucose following a glucose tolerance test. A set of additional outcomes includes other markers of glycaemic control and insulin resistance. Risk of bias (RoB) will be assessed using the Cochrane RoB 2.0 tool (human studies) and the Systematic Review Centre for Laboratory Animal Experimentation (SYRCLE) RoB tool (animal studies). Confidence in the cumulative evidence will be assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. All meta-analyses will be conducted within a Bayesian framework, providing a flexible modelling approach to account for uncertainty in model parameters and underlying structures within the data.
By including all available human and animal data, we will provide the most comprehensive overview on the topic to date. The results will have implications for those working in prediabetes, diabetes, and metabolic health in general and may lead to the development of new treatment approaches.
Study results will be presented at a professional conference and published in a peer-reviewed journal.
CRD42020191588.
糖尿病是一个重大的公共卫生问题，需要开发低成本、新颖的干预措施来预防或减缓疾病进展。越来越多的证据表明，补充肌肽或其限速前体β-丙氨酸可以改善糖尿病中发生的代谢失调的各个方面。然而，需要更好地了解其影响的幅度以及与积极结果相关的因素。本系统评价和荟萃分析的目的是评估肌肽或β-丙氨酸补充剂对人类和动物的血糖控制和胰岛素抵抗标志物的影响。
我们将对随机和非随机对照试验进行系统搜索。将通过搜索电子数据库、临床试验登记处、作者审查和交叉引用来检索研究。主要结果包括以下三个方面的变化：（i）葡萄糖耐量试验后空腹血糖、（ii）糖化血红蛋白和（iii）2 小时血糖。一套附加的结果包括其他血糖控制和胰岛素抵抗标志物。使用 Cochrane RoB 2.0 工具（人类研究）和系统评价中心对实验室动物实验的 RoB 工具（动物研究）评估风险偏倚（RoB）。使用推荐评估、制定与评估（GRADE）方法评估累积证据的置信度。所有荟萃分析将在贝叶斯框架内进行，为模型参数和数据中潜在结构的不确定性提供灵活的建模方法。
通过纳入所有可用的人类和动物数据，我们将提供迄今为止该主题最全面的概述。研究结果将对从事糖尿病前期、糖尿病和一般代谢健康的人产生影响，并可能导致新的治疗方法的发展。
研究结果将在专业会议上展示，并在同行评议的期刊上发表。
CRD42020191588。
