Background

Obesity is a major risk factor for adverse outcomes after infection with SARS-CoV-2. We aimed to examine this association, including interactions with demographic and behavioural characteristics, type 2 diabetes, and other health conditions.

Methods

In this prospective, community-based, cohort study, we used de-identified patient-level data from the QResearch database of general practices in England, UK. We extracted data for patients aged 20 years and older who were registered at a practice eligible for inclusion in the QResearch database between Jan 24, 2020 (date of the first recorded infection in the UK) and April 30, 2020, and with available data on BMI. Data extracted included demographic, clinical, clinical values linked with Public Health England's database of positive SARS-CoV-2 test results, and death certificates from the Office of National Statistics. Outcomes, as a proxy measure of severe COVID-19, were admission to hospital, admission to an intensive care unit (ICU), and death due to COVID-19. We used Cox proportional hazard models to estimate the risk of severe COVID-19, sequentially adjusting for demographic characteristics, behavioural factors, and comorbidities.

Findings

Among 6 910 695 eligible individuals (mean BMI 26·78 kg/m² [SD 5·59]), 13 503 (0·20%) were admitted to hospital, 1601 (0·02%) to an ICU, and 5479 (0·08%) died after a positive test for SARS-CoV-2. We found J-shaped associations between BMI and admission to hospital due to COVID-19 (adjusted hazard ratio [HR] per kg/m² from the nadir at BMI of 23 kg/m² of 1·05 [95% CI 1·05–1·05]) and death (1·04 [1·04–1·05]), and a linear association across the whole BMI range with ICU admission (1·10 [1·09–1·10]). We found a significant interaction between BMI and age and ethnicity, with higher HR per kg/m² above BMI 23 kg/m² for younger people (adjusted HR per kg/m² above BMI 23 kg/m² for hospital admission 1·09 [95% CI 1·08–1·10] in 20–39 years age group vs 80–100 years group 1·01 [1·00–1·02]) and Black people than White people (1·07 [1·06–1·08] vs 1·04 [1·04–1·05]). The risk of admission to hospital and ICU due to COVID-19 associated with unit increase in BMI was slightly lower in people with type 2 diabetes, hypertension, and cardiovascular disease than in those without these morbidities.

Interpretation

At a BMI of more than 23 kg/m², we found a linear increase in risk of severe COVID-19 leading to admission to hospital and death, and a linear increase in admission to an ICU across the whole BMI range, which is not attributable to excess risks of related diseases. The relative risk due to increasing BMI is particularly notable people younger than 40 years and of Black ethnicity.

Funding

NIHR Oxford Biomedical Research Centre.

中文翻译：

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英格兰 6·900 万人的体重指数与 COVID-19 严重程度之间的关联：一项基于社区的前瞻性队列研究

背景

肥胖是感染 SARS-CoV-2 后不良后果的主要风险因素。我们旨在检查这种关联，包括与人口统计和行为特征、2 型糖尿病和其他健康状况的相互作用。

方法

在这项前瞻性、基于社区的队列研究中，我们使用了来自英国英格兰全科医学 QResearch 数据库的去识别患者级别数据。我们提取了 20 岁及以上患者的数据，这些患者在 2020 年 1 月 24 日（英国首次记录感染的日期）至 2020 年 4 月 30 日期间在符合纳入 QResearch 数据库的实践中注册，并提供了关于体重指数。提取的数据包括与英国公共卫生部 SARS-CoV-2 阳性检测结果数据库相关的人口统计、临床、临床值，以及国家统计局的死亡证明。作为衡量严重 COVID-19 的替代指标，结果是入院、入住重症监护室 (ICU) 和因 COVID-19 导致的死亡。我们使用 Cox 比例风险模型来估计严重 COVID-19 的风险，

发现

在 6 910 695 名符合条件的个体中（平均 BMI 26·78 kg/m ² [SD 5·59]），13 503 人（0·20%）入院，1601 人（0·02%）住进 ICU，5479 人(0·08%) 在 SARS-CoV-2 检测呈阳性后死亡。我们发现 BMI 与因 COVID-19 入院之间存在 J 型关联（从1·05的 BMI 为 23 kg/m ^{2的最低点调整后的风险比 [HR] 每 kg/m 2} [95% CI 1· 05–1·05]) 和死亡 (1·04 [1·04–1·05])，并且在整个 BMI 范围内与入住 ICU 呈线性相关 (1·10 [1·09–1·10]) . 我们发现 BMI 与年龄和种族之间存在显着的相互作用，对于年轻人来说，每 kg/m 2 的 HR 高于 BMI 23 kg/m 2 （调整后的 HR per kg/m ²高于^{BMI 23} kg/m ²20-39 岁年龄组与80-100 岁组 1·01 [1·00-1·02]入院 1·09 [95% CI 1·08-1·10 ]）和黑人比白人（1·07 [1·06–1·08]与1·04 [1·04–1·05]）。与没有这些疾病的人相比，患有 2 型糖尿病、高血压和心血管疾病的人因 COVID-19 与 BMI 单位增加相关而入院和 ICU 的风险略低。

解释

当 BMI 超过 23 kg/m ²时，我们发现导致入院和死亡的严重 COVID-19 风险线性增加，并且在整个 BMI 范围内进入 ICU 的风险线性增加，这不是归因于相关疾病的过度风险。BMI 增加带来的相对风险在 40 岁以下和黑人族裔中尤为显着。

资金

NIHR 牛津生物医学研究中心。