Socio-demographics factors relating to obesity and the development and progression of arthritis in the UK

肥胖被定义为异常或过度的脂肪积累，在全球范围内正在增加。自20世纪90年代中期以来，英国成年人肥胖率上升了15%，是西欧最严重的之一：现在几乎三分之一的成年人患有肥胖症。肥胖是一种复杂和多因素的疾病；大量研究表明，社会人口因素，如低收入，与较高的肥胖率有关。关节炎，包括骨关节炎(OA)和类风湿性关节炎(RA)，在英国估计影响多达1000万人，是导致工作残疾的主要原因，估计每年造成70亿英镑的损失。与肥胖类似，骨质疏松症也与几个社会人口因素有关，包括教育、收入和职业的类型和水平。最重要的是，肥胖者的骨性关节炎发生率较高，关节置换手术等疾病结局较差。相比之下，RA的研究表明，社会人口因素与疾病发生之间的关联较弱。然而，吸烟的情况并非如此；研究表明，吸烟的人患类风湿性关节炎的几率较高，但肥胖率较低。这表明肥胖可能是某些社会决定因素与疾病发生和发展之间关系的重要中介。肥胖和类风湿性关节炎之间的联系不太清楚；一些研究报告肥胖是类风湿性关节炎的危险因素，但肥胖者的预后和类风湿关节炎的严重程度似乎比非肥胖者更好。这个项目的目的是使用不同的队列来了解社会决定因素、肥胖和关节炎之间的关系，这些队列包括来自广泛社会的个人、老年群体中的个人和患有早期炎症性关节炎的个人。这将通过以下目标来实现：-在英语老龄化纵向研究(ELSA)和理解协会(US)中确定肥胖和关节炎事件的不同定义之间的联系-基于问卷确定ELSA和美国的关节炎亚型(即骨关节炎/炎症性关节炎)，现有的生物标志物和药物--调查社会人口因素在肥胖和美国和ELSA目标2中定义的关节炎亚型之间的因果路径上的中介作用--在(I)目标2中定义的美国和ELSA中定义的关节炎亚型和(Ii)诺福克关节炎登记册(NOAR)中定义的早期炎症性关节炎中，确定肥胖和疾病进展之间的联系。这些目标将使用不同类型的数据集来解决，其中包含有关社会人口因素、肥胖和关节炎的信息。因此，这项研究将使用来自两个具有全国代表性的调查数据集(美国和ELSA)的数据和对炎症性关节炎患者的纵向观察性研究(NOAR)。

Obesity, defined as abnormal or excessive fat accumulation, is increasing globally. UK rates of adult obesity have increased by 15% since the mid-1990s and are amongst the worst in western Europe: almost one-third of the adult population now suffers from obesity. Obesity is a complex and multifactorial disease; substantial research has shown that sociodemographic factors, such as a low income, are associated with higher prevalence of obesity. Arthritis, including osteoarthritis (OA) and rheumatoid arthritis (RA), is estimated to effect up to 10 million people in the UK and is a leading cause of work disability with an estimated cost of £7 billion per year. Similarly to obesity, OA has been linked to several socio-demographic factors, including the type and level of education, income and occupation. On top of that, people with obesity have higher rates of OA and poor disease outcomes, such as joint replacement surgery.In contrast, studies in RA show a weaker association between socio-demographic factors and disease occurrence. However, this is not the case for smoking; research has shown that people who smoke cigarettes have higher rates of RA, but lower rates of obesity. This demonstrates that obesity may be an important mediator in the relationship between certain social determinants and the occurrence and progression of disease. The association between obesity and RA is less clear; some studies have reported obesity as a risk factor for RA, but the prognosis and severity of RA appears to be better in obese compared to non-obese patients. The aim of this project is to understand the relationship between social determinants, obesity and arthritis using different cohorts encompassing individuals from a wide range of society, individuals in older age groups and individuals with early inflammatory arthritis. This will be achieved through the following objectives:- to identify the association between different definitions of obesity and incident arthritis in the English Longitudinal Study of Ageing (ELSA) and Understanding Society (US)- to define subtypes of arthritis (i.e. osteoarthritis / inflammatory arthritis) in ELSA and US based on questionnaires, available biomarkers and medications- to investigate the mediating role of socio-demographic factors on the causal pathway between obesity and subtypes of arthritis defined in objective 2 in US and ELSA- to identify associations between obesity and progression of disease in (i)subtypes of arthritis in US and ELSA defined in objective 2 and (ii)early inflammatory arthritis in the Norfolk Arthritis Register (NOAR)These objectives will be addressed using different types of datasets, which contain information on socio-demographic factors, obesity and arthritis. This study will therefore use data from two nationally representative survey datasets (US and ELSA) and a longitudinal observational study of patients with inflammatory arthritis (NOAR).