Association between the overall burden of comorbidity and Ct values among the older patients with Omicron infection: Mediated by inflammation

Meixia Wang; Hongfei Mi; Na Li; Qingfeng Shi; Wei Sun; Tingjuan He; Jiabing Lin; Wenting Jin; Xiaodong Gao; Bijie Hu; Chenghao Su; Jue Pan

doi:10.3389/fimmu.2023.1145044

Association between the overall burden of comorbidity and Ct values among the older patients with Omicron infection: Mediated by inflammation

Front Immunol. 2023 Mar 14:14:1145044. doi: 10.3389/fimmu.2023.1145044. eCollection 2023.

Authors

Meixia Wang¹, Hongfei Mi¹, Na Li², Qingfeng Shi³, Wei Sun³, Tingjuan He¹, Jiabing Lin³, Wenting Jin², Xiaodong Gao³, Bijie Hu^{2

3}, Chenghao Su¹, Jue Pan^{1

2}

Affiliations

¹ Department of Hospital Infection Management, Zhongshan Hospital, Fudan University (Xiamen Branch), Xiamen, Fujian, China.
² Department of Infectious Diseases, Zhongshan Hospital, Fudan University, Shanghai, China.
³ Department of Hospital Infection Management, Zhongshan Hospital, Fudan University, Shanghai, China.

Abstract

Objectives: To investigate the associations between the overall burden of comorbidity, inflammatory indicators in plasma and Ct values among the elderly with COVID-19.

Methods: We conducted a retrospective observational study. The results of each nucleic acid test of during hospitalization were obtained. Linear regression models assessed the associations between the overall burden of comorbidity, inflammatory indicators in plasma and Ct values among the elderly. A causal mediation analysis was performed to assess the mediation effects of inflammatory indicators on the association between the overall burden of comorbidity and Ct values.

Results: A total of 767 COVID-19 patients aged ≥ 60 years were included between April 2022 and May 2022. Patients with a high burden of comorbidity had significantly lower Ct values of the ORF gene than subjects with a low burden of comorbidity (median, 24.81 VS 26.58, P < 0.05). Linear regression models showed that a high burden of comorbidity was significantly associated with higher inflammatory responses, including white blood cell count, neutrophil count and C-reactive protein. Also, white blood cell count, neutrophil count, C-reactive protein and the overall burden of comorbidity assessed by age-adjusted Charlson comorbidity index were independent risk factors for the Ct values. A mediation analysis detected the mediation effect of white blood cells on the association between the burden of comorbidity and Ct values, with the indirect effect estimates of 0.381 (95% CI: 0.166, 0.632, P < 0.001). Similarly, the indirect effect of C-reactive protein was -0.307 (95% CI: -0.645, -0.064, P = 0.034). White blood cells and C-reactive protein significantly mediated the relationship between the burden of comorbidity and Ct values by 29.56% and 18.13% of the total effect size, respectively.

Conclusions: Inflammation mediated the association between the overall burden of comorbidity and Ct values among elderly with COVID-19, which suggests that combined immunomodulatory therapies could reduce the Ct values for such patients with a high burden of comorbidity.

Keywords: CT values; SARS-CoV-2; comorbidity burden; inflammation; mediation effect; the elderly.

Publication types

Observational Study
Research Support, Non-U.S. Gov't

MeSH terms

Aged
C-Reactive Protein / analysis
COVID-19* / epidemiology
Comorbidity
Humans
Inflammation / epidemiology
SARS-CoV-2

Substances

C-Reactive Protein

Grants and funding

This work was supported by the Xiamen medical and health guiding project (grants numbers 3502Z20224ZD1094 and 3502Z20214ZD1069) and Xiamen Science and Technology Bureau 2022 General Science and Technology Plan Project (Emergency Project) [grant numbers 35022022YJ07].