Background and purpose

The coronavirus disease 2019 (COVID-19) pandemic presents an unprecedented health crisis to the entire world. As reported, the body mass index (BMI) may play an important role in COVID-19; however, this still remains unclear. The aim of this study was to explore the association between BMI and COVID-19 severity and mortality.

Methods

The Medline, PubMed, Embase and Web of science were systematically searched until August 2020. Random-effects models and dose-response meta-analysis were used to synthesize the results. Combined odds ratios (ORs) with their 95% confidence intervals (CIs) were calculated, and the effect of covariates were analyzed using subgroup analysis and meta-regression analyses.

Results

A total of 16 observational studies involving 109,881 patients with COVID-19 were included in the meta-analysis. The pooled results showed that patients with a BMI ≥ 30 kg/m² had a 2.35-fold risk (OR = 2.35, 95%CI = 1.64–3.38, P < 0.001) for critical COVID-19 and a 2.68-fold risk for COVID-19 mortality (OR = 2.68, 95%CI = 1.65–4.37, P < 0.001) compared with patients with a BMI <30 kg/m². Subgroup analysis results showed that patients with obesity and age > 60 years was associated with a significantly increased risk of critical COVID-19 (OR = 3.11, 95%CI = 1.73–5.61, P < 0.001) and COVID-19 mortality (OR = 3.93, 95%CI = 2.18–7.09, P < 0.001). Meta-regression analysis results also showed that age had a significant influence on the association between BMI and COVID-19 mortality (Coef. = 0.036, P = 0.048). Random-effects dose-response meta-analysis showed a linear association between BMI and both critical COVID-19(P_{non-linearity} = 0.242) and mortality (P_{non-linearity} = 0.116). The risk of critical COVID-19 and mortality increased by 9%(OR = 1.09, 95%CI = 1.04–1.14, P < 0.001) and 6%(OR = 1.06, 95%CI = 1.02–1.10, P = 0.002) for each 1 kg/m² increase in BMI, respectively.

Conclusions

Evidence from this meta-analysis suggested that a linear dose-response association between BMI and both COVID-19 severity and mortality. Further, obesity (BMI ≥ 30 kg/m²) was associated with a significantly increased risk of critical COVID-19 and in-hospital mortality of COVID-19.

中文翻译：

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体重指数 (BMI) 与危重 COVID-19 和院内死亡率的关联：剂量反应荟萃分析。

背景和目的

2019 年冠状病毒病（COVID-19）大流行给全世界带来了前所未有的健康危机。据报道，体重指数 (BMI) 可能在 COVID-19 中发挥重要作用；然而，这仍然不清楚。本研究的目的是探讨 BMI 与 COVID-19 严重程度和死亡率之间的关联。

方法

截至 2020 年 8 月，系统检索了 Medline、PubMed、Embase 和 Web of science。使用随机效应模型和剂量反应荟萃分析来综合结果。计算组合比值比 (OR) 及其 95% 置信区间 (CI)，并使用亚组分析和荟萃回归分析来分析协变量的影响。

结果

荟萃分析共纳入 16 项观察性研究，涉及 109,881 名 COVID-19 患者。汇总结果显示，BMI ≥ 30 kg/m ²的患者患重症 COVID-19 的风险是 2.35 倍（OR = 2.35，95%CI = 1.64–3.38，P < 0.001），患重症 COVID-19 的风险是 2.68 倍。与 BMI <30 kg/m ²的患者相比，COVID-19 死亡率（OR = 2.68，95%CI = 1.65–4.37，P < 0.001）。亚组分析结果显示，肥胖且年龄 > 60 岁的患者与重症 COVID-19 风险（OR = 3.11，95%CI = 1.73–5.61，P < 0.001）和 COVID-19 死亡率（OR = 3.93，95%CI = 2.18–7.09，P < 0.001）。荟萃回归分析结果还显示，年龄对BMI与COVID-19死亡率之间的关联有显着影响（Coef. = 0.036，P = 0.048）。随机效应剂量反应荟萃分析显示，BMI 与危重 COVID-19（P_非线性 = 0.242）和死亡率（P_非线性 = 0.116）之间存在线性相关性。重症COVID-19和死亡率的风险增加9%（OR = 1.09，95%CI = 1.04–1.14，P < 0.001）和6%（OR = 1.06，95%CI = 1.02–1.10，P = 0.002） BMI每增加1 kg/m ^{2 。}

结论

这项荟萃分析的证据表明，BMI 与 COVID-19 严重程度和死亡率之间存在线性剂量反应相关性。此外，肥胖（BMI ≥ 30 kg/m ²）与严重COVID-19风险和COVID-19院内死亡率显着增加相关。