Department of Clinical Epidemiology, Aarhus University, Aarhus, Denmark; Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark; Steno Diabetes Center Aarhus, Aarhus University Hospital, Aarhus, Denmark. Electronic address: https://twitter.com/SGribsholt.
Department of Clinical Epidemiology, Aarhus University, Aarhus, Denmark.
Mayo Clin Proc. 2021 Mar;96(3):550-562. doi: 10.1016/j.mayocp.2020.06.062.
To examine the association between body mass index (BMI) and mortality after hospitalization for infection because obesity is associated with increased energy reserves that may protect against death from severe infections.
Of 76,044 patients admitted with a primary infection diagnosis from January 1, 2011, to September 30, 2015, in Central Denmark, we examined a subgroup of 35,406 patients with a known BMI. We compared the 90-day death risk among patients with underweight, overweight, or obesity with a reference cohort of normal-weight patients. We also examined the impact of comorbid conditions, including cancer, tobacco smoking, and recent weight changes, on the associations and adjusted for other potential confounding factors.
The 90-day mortality after hospital admission was 9.8% (3479 of 35,406) for any infection, 10.5% (466 of 4425) for urinary tract infection, 17.3% (1536 of 8855) for pneumonia, 24.9% (986 of 3964) for sepsis, and 6.2% (114 of 1831) for skin infection. The 90-day adjusted hazard ratio (aHR) for death was substantially increased in patients with underweight (aHR, 1.75; 95% CI, 1.58 to 1.94) compared with normal-weight patients. In contrast, mortality aHRs were decreased in patients with overweight (aHR, 0.64; 95% CI; 0.58 to 0.69) and obesity (aHR, 0.55; 95% CI; 0.49 to 0.62). Mortality reductions with overweight and obesity were consistent for all major infection types and remained robust independent of recent weight changes, smoking status, or comorbid conditions. Mortality was highest in patients without an apparent reason for their underweight (smoking/known disease), suggesting a role of undiagnosed comorbid conditions.
We found evidence that higher BMI (overweight and obesity) is associated with improved survival following acute hospitalization for infection, whereas underweight increases the risk for death.
研究身体质量指数（BMI）与感染住院后死亡率之间的关系，因为肥胖与能量储备增加有关，而能量储备可能有助于预防严重感染导致的死亡。
在丹麦中部，我们对 2011 年 1 月 1 日至 2015 年 9 月 30 日期间因原发性感染住院的 76044 名患者进行了研究，选取了已知 BMI 的 35406 名患者作为亚组进行研究。我们比较了体重过轻、超重或肥胖患者与正常体重患者的 90 天内死亡风险。我们还研究了合并症（包括癌症、吸烟和近期体重变化）对这些关联的影响，并调整了其他潜在的混杂因素。
任何感染的 90 天死亡率为 9.8%（3479/35406），尿路感染为 10.5%（466/4425），肺炎为 17.3%（1536/8855），败血症为 24.9%（986/3964），皮肤感染为 6.2%（114/1831）。与正常体重患者相比，体重过轻患者的 90 天调整后的死亡风险比（aHR）显著升高（aHR，1.75；95%置信区间，1.58 至 1.94）。相反，超重患者（aHR，0.64；95%置信区间，0.58 至 0.69）和肥胖患者（aHR，0.55；95%置信区间，0.49 至 0.62）的死亡率 aHR 降低。超重和肥胖患者的死亡率降低在所有主要感染类型中均一致，并且独立于近期体重变化、吸烟状况或合并症而保持稳健。体重过轻且无明显原因（吸烟/已知疾病）的患者死亡率最高，这表明存在未确诊的合并症。
我们有证据表明，较高的 BMI（超重和肥胖）与急性感染住院后生存改善有关，而体重过轻则增加了死亡风险。
