BMI trajectories in middle to old age: methodological developments, missing data and cost-effectiveness

中老年BMI轨迹：方法发展、缺失数据和成本效益

• 批准号: MR/S009868/1
• 负责人: Laura Gray
• 金额: $ 37.24万
• 依托单位: University of Sheffield
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2018
• 资助国家: 英国
• 起止时间: 2018 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=MR%2FS009868%2F1
• 关键词: BMI; trajectories; middle; old; age

The UK's aging population and increasing obesity prevalence are two of the most significant public health challenges. Currently, more than 3 million people aged 80 years and over live in the UK, and this figure is projected to exceed 8 million by 2050 at increasing costs to the Department of Work and Pensions and the National Health Service. Obesity rates have almost trebled in the last 30 years at a cost of over £3 billion a year and, if forecasting is correct, over half our population will be obese by 2050. Significant obesity related co-morbidities (e.g. diabetes, osteoarthritis, cardiovascular disease), coupled with multiple health problems associated with aging (e.g. Alzheimer's disease, arthritis and cancer), places older people at significant risk. While there is a focus on obesity research in young people and the general adult population, there is relatively little research into how obesity develops into old age and the consequences of obesity in older adults. It is useful to predict BMI trajectories in patients with different characteristics in order to inform public health policies. If predictions can be made for a patient's future BMI, then these long-term estimates can be used in economic models in order to estimate how cost-effective potential interventions, actions or policies are expected to be. For policy purposes, it is critical to understand how these effects develop over time, and longitudinal analyses are relied upon to provide these long-term predictions. A number of cost-effectiveness analyses have used BMI trajectories, including models for diabetes. Previous research has investigated mean BMI trajectories and has shown that they differ as patients go from middle age to older age. However, it is well known that obesity prevalence and BMI differ between different social groups and that an individual's environment can have a large influence on their weight. This project will identify different groups of individuals who are likely to experience different types of BMI trajectories. Medical literature suggests that there are certain types of individual who are more likely to see a drop in BMI as they enter old age, known as the 'obesity paradox' because BMI drops but body fat percentage increases. In this group of people, BMI might be misleading and measures of muscle mass (such as grip strength) could be an important in identifying individuals with similar BMI trajectories but different risks of obesity. These different trajectories will also be linked with long term health outcomes, including a range of diseases and death. Missing data can be a particular problem when researching the elderly due to illness, memory loss and access to individuals in care homes. This could mean that in a sample of individuals over the age of 50 years, more elderly individuals are under-represented. In order to account for the potential underrepresentation of certain individuals, analysis should account for missing data and this study will investigate the influence that missing data might have on estimated BMI trajectories.The study will use data from the English Longitudinal Study of Aging (ELSA) and the analysis described above will provide more detailed evidence for health care professionals helping to identify those most at risk of morbidities and mortality by the BMI trajectories that they are expected to follow. The results will also be used to inform cost-effectiveness analyses, which can help policy makers to determine the most cost-effective interventions to help improve the health of future generations as they enter old age. I will use a diabetes prevention model as a case study, to illustrate how potential diabetes prevention interventions might influence patients with different characteristics and to demonstrate the impact that missing data could have on policy if it remained unaccounted for.

英国的人口老龄化和日益增加的肥胖患病率是两个最重大的公共卫生挑战。目前，超过300万80岁及以上的人生活在英国，预计到2050年这一数字将超过800万，这将增加工作和养老金部以及国民保健服务的成本。在过去的30年里，肥胖率几乎增加了两倍，每年的成本超过30亿英镑，如果预测正确，到2050年，我们一半以上的人口将肥胖。与肥胖相关的严重共病（如糖尿病、骨关节炎、心血管疾病），加上与衰老相关的多种健康问题（如阿尔茨海默病、关节炎和癌症），使老年人面临重大风险。虽然人们关注年轻人和普通成年人的肥胖研究，但对肥胖如何发展到老年以及老年人肥胖的后果的研究相对较少。预测具有不同特征的患者的BMI轨迹是有用的，以便为公共卫生政策提供信息。如果可以对患者未来的BMI进行预测，那么这些长期估计可以用于经济模型，以估计潜在干预措施、行动或政策的成本效益。出于政策目的，了解这些影响如何随着时间的推移而发展至关重要，并且依赖于纵向分析来提供这些长期预测。许多成本效益分析使用BMI轨迹，包括糖尿病模型。先前的研究调查了平均BMI轨迹，并表明随着患者从中年到老年，它们会有所不同。然而，众所周知，肥胖患病率和BMI在不同的社会群体之间是不同的，个人的环境可能对他们的体重有很大的影响。该项目将确定可能经历不同类型BMI轨迹的不同人群。医学文献表明，某些类型的人在进入老年时更有可能看到BMI下降，这被称为“肥胖悖论”，因为BMI下降，但体脂百分比增加。在这组人群中，BMI可能具有误导性，肌肉质量（如握力）的测量对于识别BMI轨迹相似但肥胖风险不同的个体可能很重要。这些不同的轨迹也将与长期健康结果相关联，包括一系列疾病和死亡。在研究老年人因疾病、记忆丧失和接触养老院的个人时，缺失数据可能是一个特别的问题。这可能意味着，在50岁以上的个人样本中，更多的老年人代表性不足。为了说明某些人可能任职人数不足的情况，分析应考虑缺失数据，本研究将调查缺失数据可能对估计BMI轨迹的影响。本研究将使用英国老龄化纵向研究（艾尔莎）的数据上述分析将为卫生保健专业人员提供更详细的证据，帮助确定那些最有发病风险的人，他们预期遵循的BMI轨迹。研究结果还将用于为成本效益分析提供信息，这将有助于决策者确定最具成本效益的干预措施，以帮助改善进入老年的后代的健康状况。我将使用一个糖尿病预防模型作为案例研究，以说明潜在的糖尿病预防干预措施可能如何影响具有不同特征的患者，并证明缺失数据可能对政策产生的影响，如果它仍然无法解释。

项目成果

PMU30 BMI Trajectories, Mortality and Comorbidity in Older Adults

PMU30 老年人的 BMI 轨迹、死亡率和合并症

• DOI: 10.1016/j.jval.2020.08.1242
• 发表时间: 2020
• 期刊: Value in Health
• 影响因子: 4.5
• 作者: Gray L

An age-period-cohort approach to studying long-term trends in obesity and overweight in England (1992-2019).

研究英格兰肥胖和超重长期趋势的年龄阶段队列方法（1992-2019）。

• DOI: 10.1002/oby.23657
• 发表时间: 2023
• 期刊: Obesity (Silver Spring, Md.)
• 作者: Opazo Breton M

Estimating the impact of changes in weight and BMI on EQ-5D-3L: a longitudinal analysis of a behavioural group-based weight loss intervention.

• DOI: 10.1007/s11136-022-03178-z
• 发表时间: 2022-11
• 期刊: QUALITY OF LIFE RESEARCH
• 影响因子: 3.5
• 作者: Breeze, Penny;Gray, Laura A.;Thomas, Chloe;Bates, Sarah E.;Brennan, Alan
• 通讯作者: Brennan, Alan

BMI trajectories, morbidity, and mortality in England: a two-step approach to estimating consequences of changes in BMI.

英格兰的BMI轨迹，发病率和死亡率：估计BMI变化后果的两步方法。

• DOI: 10.1002/oby.23510
• 发表时间: 2022-09
• 期刊: Obesity (Silver Spring, Md.)

A latent class analysis of change and continuity in adolescent health and wellbeing in England during the decline in youth alcohol consumption: A repeat cross-sectional study.

• DOI: 10.1016/j.pmedr.2023.102481
• 发表时间: 2023-12
• 期刊: PREVENTIVE MEDICINE REPORTS
• 影响因子: 2.8
• 作者: Stevely, Abigail Kate;Gray, Laura A.;Fairbrother, Hannah;Fenton, Laura;Henney, Madeleine;Holmes, John
• 通讯作者: Holmes, John