Impact of body composition on patient prognosis after SARS-Cov-2 infection

PLOS ONE RESEARCH ARTICLE Impact of body composition on patient prognosis after SARS-Cov-2 infection Takayuki Yamamoto1, Kazushi Sugimoto2, Syuhei Ichikawa1, Kei Suzuki3, Hideki Wakabayashi1, Kaoru Dohi ID4, Norihiko Yamamoto ID1* 1 Department of General Medicine, Mie University Hospital, Tsu, Japan, 2 Department of Clinical Laboratory, Mie University Hospital, Tsu, Japan, 3 Department of Infectious Disease, Mie University Hospital, Tsu, Japan, 4 Department of Cardiology and Nephrology, Mie University Hospital, Tsu, Japan * a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 Abstract Background OPEN ACCESS Citation: Yamamoto T, Sugimoto K, Ichikawa S, Suzuki K, Wakabayashi H, Dohi K, et al. (2023) Impact of body composition on patient prognosis after SARS-Cov-2 infection. PLoS ONE 18(7): e0289206. https://doi.org/10.1371/journal. pone.0289206 Editor: Jun Mori, Osaka City General Hospital, Children’s Medical Center, JAPAN Received: January 16, 2023 Accepted: July 13, 2023 Published: July 28, 2023 Peer Review History: PLOS recognizes the benefits of transparency in the peer review process; therefore, we enable the publication of all of the content of peer review and author responses alongside final, published articles. The editorial history of this article is available here: https://doi.org/10.1371/journal.pone.0289206 Copyright: © 2023 Yamamoto et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All relevant data are within the paper and its Supporting Information files. Since the first outbreak of coronavirus disease 2019 (COVID-19), it has been reported that several factors, including hypertension, type 2 diabetes mellitus, and obesity, have close relationships with a severe clinical course. However, the relationship between body composition and the prognosis of COVID-19 has not yet been fully studied. Methods The present study enrolled 76 consecutive COVID-19 patients with computed tomography (CT) scans from the chest to the pelvis at admission. The patients who needed intubation and mechanical ventilation were defined as severe cases. Patients were categorized into four groups according to their body mass index (BMI). The degree of hepatic steatosis was estimated by the liver/spleen (L/S) ratio of the CT values. Visceral fat area (VFA), psoas muscle area (PMA), psoas muscle mass index (PMI), and intra-muscular adipose tissue content (IMAC) were measured by CT scan tracing. These parameters were compared between non-severe and severe cases. Results Severe patients had significantly higher body weight, higher BMI, and greater VFA than non-severe patients. However, these parameters did not have an effect on disease mortality. Furthermore, severe cases had higher IMAC than non-severe cases in the non-obese group. Conclusions Our data suggest high IMAC can be a useful predictor for severe disease courses of COVID-19 in non-obese Japanese patients, however, it does not predict either disease severity in obese patients or mortality in any obesity grade. PLOS ONE | https://doi.org/10.1371/journal.pone.0289206 July 28, 2023 1 / 13 PLOS ONE Funding: The author(s) received no specific funding for this work. Competing interests: The authors have declared that no competing interests exist. Abbreviations: COVID-19, coronavirus disease 2019; BMI, body mass index; VFA, visceral fat area; PMA, psoas muscle area; PMI, psoas muscle mass index; IMAC, intra-muscular adipose tissue content; SARS-Cov-2, Respiratory SyndromeCoronavirus-2. Impact of body composition on patient prognosis after SARS-Cov-2 infection Introduction Since the first outbreak in Wuhan, China in 2019, coronavirus disease 2019 (COVID-19), which is caused by Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-Cov-2), has spread worldwide. While most cases of other coronavirus infections were acute and cleared quickly, COVID-19 has sometimes been fatal, with a mortality rate of around 2% initially [1], and the most common cause of death was acute respiratory distress syndrome (ARDS). Factors that can predict disease severity and worse outcomes in COVID-19 patients have been investigated in many studies. In these studies, it was suggested that several risk factors were associated with worse disease outcomes, including high age [2], type 2 diabetes mellitus (T2DM) [3], and cardiovascular disease (CVD) [4]. In addition, many studies, including a meta-analysis, showed the COVID-19 patients with obesity had a worse disease course [5–7]. For example, Zhang et al. analyzed 22 cohort studies from seven countries performed in the first six months of the pandemic and showed that obese patients had more severe disease than non-obese patients and were more likely to develop ARDS or need invasive mechanical ventilation, but obesity per se. was not associated with the mortality of COVID-19 [6]. Another study by Chu et al. also found that, though obesity was a risk factor for severe COVID-19, especially in younger patients, it did not increase the risk of hospital mortality [5]. In most studies that linked obesity and COVID-19 outcome, obesity was assessed by body mass index (BMI). However, using the BMI to determine obesity has several problems. First, the definition of obesity is different across countries. For instance, the diagnostic criterion for obesity is BMI � 30 kg/m2 in the United States and European countries, but patients with BMI � 25 kg/m2 are diagnosed as obese in Japan. In fact, two previous meta-analyses by Zhang and Wang included studies that had different BMI cut-offs to define obesity. Second, because BMI is calculated only by body weight and height, it sometimes does not reflect body composition precisely. A certain number of individuals have excess body fat despite a normal BMI, and these individuals usually have excess visceral fat, which leads to insulin resistance, T2DM, hypertension, and metabolic syndrome, as well as obese individuals. Therefore, we may miss the patients who potentially have the same risks as obese patients by assessing BMI alone. For this reason, Stevanovic et al. examined the effects of body and visceral fat mass on the course and outcome of COVID-19 in Serbian patients, and they found that these parameters were stronger predictors of outcome than BMI alone [8]. Furthermore, it has recently been reported that body composition indices, such as muscle mass or degree of muscular fatty degeneration, are also related to worse prognoses of several diseases, including malignant disease and acute illness [9–12]. However, the relationship with the outcome of COVID-19 has not yet been fully clarified. Taking these findings from previous studies into account, in the current study, the impacts of body composition indices, including the psoas muscle mass index (...truncated)