We next analyzed the serum lipid levels (in mmol/L) of the patients before they were infected by SARS-CoV-2 and during their entire courses of the disease. The average timeline of disease course was shown in Fig. 1 . The low-density lipoprotein (LDL) levels in all patients showed significant decreases at the time on admission as compared to the levels prior to infection (pre-infection: 3.5 (3.0–4.4); admission: 2.8 (2.3–3.1), p < 0.01); the LDL levels remained relatively low during the treatment (2.5 (2.3–3.0)) and returned to the levels prior to infection in patients that survived by the time of discharge (3.6 (2.7–4.1)) (Fig. 1, Supplementary Table S1). The high-density lipoprotein (HDL) levels also showed significant decreases at the time on admission as compared to levels prior to infection (pre-infection: 1.4 (1.0–1.8); admission: 1.1 (0.8–1.4), p = 0.03). Unlike LDL, HDL levels remained relatively low during the treatment stage and after recovery (progression: 1.2 (1.0–1.4); discharge: 1.0 (1.0–1.4)) (Fig. 1, Supplementary Table S1). Total cholesterol (TC) levels showed a pattern similar to LDL during the disease course (pre-infection: 5.2 (4.6–6.5); admission: 3.5 (3.3–4.1), p < 0.01; progression: 4.5 (4.0–4.8); discharge: 5.2 (4.4–6.1); Fig. 1, Supplementary Table S1).
Fig. 1 Ratio changes for LDL (A), HDL (B) and TC (C) in COVID-19 patients during the course of disease. For each data point, the ratio is normalized to the levels of LDL, HDL and TC prior to infection for the same patient. The days listed are the duration (median (IQR)) for each period during the disease course. The date on admission is set as “day 0”. Data is presented as “mean ± 95% confidence interval”. # indicates p < 0.05 as compared to the levels of pre-infection stage, and * indicates p < 0.05 as compared to the levels on admission, by a Mann-Whitney U test. The sample actual values at each stage are listed in Supplementary Table S1. The ratios of hsCRP at each time point are normalized to the levels prior to infection in the same patients. Pearson correlation coefficient analysis show the ratios of hsCRP significantly inversely correlated with the ratios of LDL (D), HDL (E) and TC (F) during the disease course; n = 33 data pairs for each analysis.