Development of nutritional strategies for diabetes prevention in Malawian adults at high diabetes risk

马拉维等低收入和中等收入国家目前面临着不同的营养挑战，如儿童和成人营养不良以及日益严重的肥胖症。最重要的是，马拉维(以及更广泛的撒哈拉以南非洲(SSA))的人们暴露在反复感染和炎症的环境中。这些因素共同导致了糖尿病等非传染性疾病在这些国家的发病率上升。SSA的糖尿病死亡率是高收入国家的5倍，这种疾病给脆弱的卫生系统带来了沉重的负担。它还具有重要的经济后果，因为它在很大程度上影响到劳动年龄的成年人。因此，重要的是在马拉维和更广泛的SSA制定预防糖尿病的战略。同样变得清晰的是，马拉维的糖尿病患者与高收入国家的欧洲白人截然不同。例如，在高收入国家，患糖尿病的人很可能肥胖(BMI超过30公斤/平方米)和不活跃，而在马拉维，90%以上的人口符合体力活动指南，通常是正常体重。这种差异可能是由于营养方面的差异，特别是在生命早期，以及感染负担的差异，这些因素共同导致马拉维人的肌肉质量和力量水平较低。事实上，与英国和美国等高收入国家相比，马拉维人的肌肉大小和力量较低：这一点很重要，因为低肌肉质量和力量已被证明会增加患糖尿病的风险。马拉维目前缺乏对糖尿病高危人群的营养习惯、身体成分和炎症负担的详细探索。在我们制定适当的干预措施来预防这一人群中的糖尿病之前，需要这些数据。在高收入国家，生活方式干预的重点是减肥(通过减少食物摄入量)和增加体力活动，这在马拉维不太可能有效，因为那里的人已经非常活跃，体重正常。因此，情况可能是这样，在马拉维，增加蛋白质摄入量或改变饮食以帮助减少炎症等营养策略可能更有效。事实上，一些初步数据显示马拉维的蛋白质摄入量普遍很低。在这项提案中，我们将对马拉维有糖尿病风险的人的营养摄入量、身体成分和感染负担进行详细测量，并将其与马拉维健康人口以及其他非洲国家和高收入国家(如英国和美国)的数据库中的现有数据进行比较。这将使我们能够确定最好的干预措施，例如通过增加蛋白质摄入量来增加肌肉质量。随后，在相同的人群中，我们将探索正常的营养实践和糖尿病知识，目的是确定可能进行有益干预的领域。第三，我们将建立一个由个人和组织组成的网络，这些人和组织将在促进任何成熟的干预方面发挥关键作用。总而言之，这些将使我们能够为马拉维降低糖尿病风险的新营养干预措施开发潜在的变化理论。这项工作将导致未来在马拉维人群中开发新的营养方法来预防糖尿病，重点是增加肌肉质量和减少炎症。

Low- and middle-income countries, such as Malawi, are currently faced with disparate nutritional challenges such as childhood and adult malnutrition alongside increasing levels of obesity. On top of this, people in Malawi (and wider sub-saharan Africa (SSA)) are exposed to repeated infections and inflammation. Together these contribute to the rising levels of non-communicable diseases, such as diabetes, in these countries. Rates of death from diabetes in SSA are 5 times higher than in high-income countries, and the disease is placing substantial burdens of fragile health systems. It also has important economic consequences as it largely affects working age adults. It is therefore important to develop strategies to prevent diabetes in Malawi and wider SSA. What is also becoming clear is that people who get diabetes in Malawi are very different from White Europeans in high-income countries. For example, whereas in high-income countries people who get diabetes are likely to be obese (BMI over 30 kg/m2) and inactive, in Malawi over 90% of the population meet physical activity guidelines and are often normal weight. This discrepancy may be explained by differences in nutrition, particularly in early life, and infection burden which come together to cause a low level of muscle mass and strength in people from Malawi. Indeed muscle size and strength are lower in people in Malawi compared to high income countries such as the UK and United States: this is important, as low muscle mass and strength have been shown to increase the risk of diabetes. A detailed exploration of nutritional habits, body composition and inflammation burden in people at risk of diabetes in Malawi is currently lacking. Such data are needed before we can develop appropriate interventions to prevent diabetes in this population. In high-income countries lifestyle interventions are focused on weight loss (via decreasing food intake) and increases in physical activity, which are unlikely to be effective in Malawi where people are already very active and normal weight. It may be the case, therefore, that nutritional strategies such as increasing protein intake or altering the diet to help reduce inflammation may be more effective in Malawi. Indeed some preliminary data has shown protein intake to be generally very low in Malawi. In this proposal we will carry out detailed measurements of nutritional intake, body composition and infection burden in people in Malawi at risk of diabetes and compare these to a healthy Malawian population and with available data from databases in other African countries and high-income countries (e.g. United Kingdom and United States). This will allow us to identify where best to target interventions, e.g. at increasing muscle mass via increases in protein intake. Following this, in the same population, we will explore normal nutritional practices and knowledge of diabetes with an aim to identify areas where beneficial intervention may be possible. Thirdly, we will form a network of people and organisations who will be key in facilitating any developed intervention. Together these will allow us to develop potential theories of change for new nutritional interventions to reduce diabetes risk in Malawi. This work will lead to the future development of new nutritional approaches to prevent diabetes in the Malawian population focused on increasing muscle mass and reducing inflammation.