The influence of sugar within an energy balanced diet on post-prandial lactate levels and T-cell regulation

乳酸盐长期以来被认为仅仅是一种代谢中间产物或最终产物。然而，今天人们知道它是影响细胞和器官的关键代谢物。乳酸盐促进胰岛素抵抗的发展，从而促进2型糖尿病的发展，还与其他非传染性疾病有关，如慢性炎症性疾病、动脉粥样硬化或癌症。免疫细胞参与了其中一些疾病，最近在类风湿性关节炎中发现，高血乳酸水平抑制了某些T细胞(CD4+和CD8+T细胞)的细胞迁移，并刺激它们产生炎症标志物。这些T细胞参与了脂肪组织慢性低度炎症的发展，由于灌流不足，这种炎症会产生过量的乳酸。糖后血乳酸水平升高；尤其是果糖摄入和长期摄入糖会增加基础乳酸水平。在一项研究中，经常饮用含糖饮料与关节炎发病率有关，尽管这种关系仍有待阐明。本项目旨在研究糖摄入对血乳酸水平的影响以及随后对特异性T淋巴细胞(CD4+和CD8+T细胞)的影响。该项目被嵌入了一项为期10周的人类干预试验，研究糖分摄入对新陈代谢的影响。研究设计为单盲、平行臂、随机对照干预研究，共四组，每组15名受试者。受试者(年龄18-40岁；体重指数22-28公斤/平方米，体重50公斤)在能量平衡饮食(没有体重增加)或控制自由饮食(可能体重增加)的同时，以高果糖玉米糖浆含糖饮料的形式摄入每日能量需要量的0%或25%。餐后乳酸水平将被评估(干预前和干预后)并与胰岛素敏感性相关。将从受试者的血液中分离T淋巴细胞，并测试特定的炎症标志物和迁移潜力。这些结果将提供关于持续的糖摄取依赖或独立于正能量平衡如何影响胰岛素抵抗和炎症性非传染性疾病的发展的知识。公共卫生部门对此非常感兴趣，因为非传染性疾病对个人和社会来说是一个日益沉重的负担。这项研究的结果将促进旨在降低游离糖消费和减轻非传染性疾病流行的公共卫生政策。

Lactate was long considered a mere metabolic intermediate or end product. However today it is known that it is a pivotal metabolite that influences cells and organs. Lactate facilitates the development of insulin resistance, and therefore type 2 diabetes, and is also associated with other non-communicable diseases like chronic inflammatory diseases, atherosclerosis or cancer. Immune cells are involved in some of those diseases and it was recently shown in rheumatoid arthritis that high blood lactate levels inhibit cell migration in certain T-cells (CD4+ und CD8+ T-cells) and stimulate them to produce inflammation markers. Those T-cells are involved in the development of chronic low-grade inflammation in the adipose tissue, which produces excessive lactate amounts due to insufficient perfusion. Lactate blood levels increase after sugar; especially fructose consumption and chronic consumption of sugar increases the basal lactate levels. Regular drinking of sugar sweetened beverages correlated with arthritis incidence in one study although the relationship remains to be elucidated. This project aims to study the influence of sugar consumption on blood lactate levels and the subsequent effects on specific T-lymphocytes (CD4+ und CD8+ T-cells). The project is embedded in a 10-week human intervention trial that studies the influence of sugar consumption on the metabolism. The study design is a single blind, parallel arm, randomized controlled intervention study with four groups (15 subjects each). The subjects (aged 18-40 years; BMI 22-28 kg/m2, with bodyweight > 50 kg) consume 0% or 25% of their daily energy requirements as high fructose corn syrup sweetened beverages alongside an energy balanced diet (no weight gain) or alongside a controlled ad libitum diet (possible weight gain). Postprandial lactate levels will be assessed (pre and post intervention) and correlated with insulin sensitivity. T-lymphocytes will be isolated from the subjects’ blood and tested for specific inflammation markers and migration potential. The results will provide knowledge on how continued sugar consumption dependent or independent of a positive energy balance influences the development of insulin resistance and inflammatory non-communicable diseases. This is of great interest to the public health sector as non-communicable diseases are an increasing burden to individuals and society. Results from this study will promote public health policies aimed at lowering free sugar consumption and attenuating the epidemics of non-communicable diseases.