Decreased Low-Density Lipoprotein Cholesterol Level Indicates Poor Prognosis of Severe and Critical COVID-19 Patients: A Retrospective, Single-Center Study

Abstract

Coronavirus disease 2019 (COVID-19) has become a global public health crisis. Reduced low-density lipoprotein cholesterol (LDL-C) levels were observed in COVID-19 patients. The present study aimed to explore the relationship between LDL-C levels and the prognosis of severe and critical COVID-19 patients. A total of 211 severe and critical COVID-19 patients were enrolled and divided into four groups according to the LDL-C levels, including 53 patients in Group A (LDL-C ≥ 2.71 mmol/L), 53 patients in Group B (2.28 ≤ LDL-C < 2.71 mmol/L), 53 patients in Group C (1.83 ≤ LDL-C < 2.28 mmol/L) and 52 patients in Group D (LDL-C < 1.83 mmol/L). LDL-C levels were lower in critically ill patients than in severe patients. The main symptoms before admission, characteristics on admission and comorbidities of enrolled patients did not differ among the four groups. Compared with patients with high LDL-C levels, patients with low LDL-C levels were more likely to have immune and inflammation dysfunction, renal dysfunction, liver dysfunction and cardiac dysfunction on admission. The proportions of patients with shock and acute cardiac injury, of those admitted to intensive care unit (ICU) and of those treated with mechanical ventilation were inversely related to LDL-C level. The mortality of COVID-19 patients increased with LDL-C reduction. Serum LDL-C levels of COVID-19 patients was negatively correlated with CRP level, but positively correlated with lymphocyte count, as shown by Pearson correlation analysis. Proportional hazard models showed that low LDL-C levels were associated with increased risk of hospitalization death, cardiac injury and admission to the ICU. Taken together, these results suggest that decreased LDL-C levels indicate poor prognosis of severe and critical COVID-19 patients.

Keywords: cardiac injury; coronavirus disease 2019; dyslipidemia; low-density lipoprotein; prognosis; severe and critical COVID-19 patients.

Conflict of interest statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Copyright © 2021 Zhao, Luo, He, Shen, Liang, Zhang, Ye, Xu, Wang, Ye, Wang and Wan.

Figures

Figure 1

Study profile.

Figure 2

Dyslipidemia was observed in severe COVID-19 patients. Serum TC, TG, LDL, HDL and LP (a) levels are presented from COVID-19 patients in the death (n = 66) and discharged groups (n = 145) (A–E), or in the critically ill (n = 80) and severe groups (n = 131) (F–J). Whiskers represent the median (IQR) in the plots. The Mann–Whitney U-test was used to compare differences between the groups. TC, total cholesterol; TG, triglyceride; LDL, low-density lipoprotein; HDL, high-density lipoprotein, LP (a), lipoprotein (a). *Means P-value < 0.05.

Figure 3

Correlations of CRP levels, CRP levels (A), hs-CRP levels (B), procalcitonin levels (C), WBC counts (D), neutrophil counts (E), lymphocyte counts (F), monocytes count (G), ALT (H) or AST levels (I) and LDL-C levels in COVID-19 patients. A Pearson correlation analysis was used. CRP, C-reactive protein; hs-CRP, high-sensitivity C-reactive protein; WBC, white blood cell; ALT, alanine aminotransferase; AST, aspartate aminotransferase; LDL-C, low-density lipoprotein cholesterol.

Figure 4

Hazard ratio for hospitalization death of severe COVID-19 patients. Shown in the figure are the hazards ratio (HR) and the 95% confidence interval (95%CI) for the risk factors of hospitalization death after disease onset with treating LDL-C levels as a categorical variable (A) or a continuous variable (B). The model has been adjusted with age, sex and comorbidities. *Means the P-value <0.05. The scale bar indicates the HR and 95%CI. LDL, low-density lipoprotein; COPD, chronic obstructive pulmonary diseases.

Figure 5

Comparison of the time-dependent risk of hospitalization death. The cumulative hospitalization death risk after disease onset in group A (blue curve), group B (green curve), group C (brown curve) and group D (red curve). The model was adjusted for age, sex and comorbidities. LDL, low-density lipoprotein; HR, hazards ratio; CI, confidence interval.

Figure 6

Hazard Ratio for cardiac injury of severe COVID-19 patients. Shown in the figure are the hazards ratio (HR) and the 95% confidence interval (95%CI) for the risk factors of cardiac injury after disease onset with treating LDL-C levels as a categorical variable (A) or a continuous variable (B). The model has been adjusted with age, sex and comorbidities. *Means the P-value <0.05. The scale bar indicates the HR and 95%CI. LDL, low-density lipoprotein; COPD, chronic obstructive pulmonary diseases.

Figure 7

Hazard Ratio for ICU admission of severe COVID-19 patients. Shown in the figure are the hazards ratio (HR) and the 95% confidence interval (95%CI) for the risk factors of ICU admission after disease onset with treating LDL-C levels as a categorical variable (A) or a continuous variable (B). The model has been adjusted with age, sex and comorbidities. *Means the P-value <0.05. The scale bar indicates the HR and 95%CI. LDL, low-density lipoprotein; COPD, chronic obstructive pulmonary diseases.