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.

Thyroid-Stimulating Hormone Predicts Total Cholesterol and Low-Density Lipoprotein Cholesterol Reduction during the Acute Phase of COVID-19

“…The observed positive association between TC and LDL-C reduction over the acute phase of COVID-19 and either CRP levels or COVID-19 severity at hospital admission is in line with the results of previous studies having shown lower TC and LDL-C levels in COVID-19 patients with a higher inflammatory burden and more severe clinical manifestations [ 8 , 31 , 32 ]. To date, several pathophysiological mechanisms have been proposed to explain the reduction of TC and LDL-C levels during the acute phase of COVID-19 in parallel with the increase of inflammatory biomarkers and disease severity.…”

Possible mechanisms of cholesterol elevation aggravating COVID-19

“…The possible mechanisms include liver damage, acute inflammation, increased free radicals, and changes in vascular permeability 64 . Compared with patients with high LDL-C levels, patients with low LDL-C levels are more likely to have immune and inflammatory dysfunction, renal dysfunction, liver dysfunction, and cardiac insufficiency on admission 118 . It is still uncertain whether the secondary hypocholesterolemia of COVID-19 patients will participate in other pathophysiological mechanisms that are not conducive to the prognosis 119 , so the lipid-lowering goal for COVID-19 patients may not be as low as possible.…”

Crosstalk among COVID-19, STRA6, Retinol, and G protein-coupled receptor may explain the novel hypothesis of Retinol depletion and retinoid signaling disorder of COVID-19 pathogenesis

“…STRA6 mediates cellular uptake of retinol by binding with the retinol-coupled RBP molecule to trigger the release and internalization of retinol, in addition to cholesterol uptake into human cells (53). It has been shown that both retinol and cholesterol decrease in COVID-19 infection (54,55,56,57). STRA6 is at the center of a complex signaling network and plays a key role (58,59).…”