Association of lipid levels with covid-19 infection, disease severity and mortality

Background: Coronavirus disease (COVID-19) caused by the SARS CoV-2 virus can range from asymptomatic infection to severe illness resulting in multiorgan failure. Recent studies have demonstrated an association between lower serum lipid levels namely high-density lipoprotein (HDL), low-density lipoprotein (LDL), and total cholesterol (TC), and COVID-19 disease severity, but lack consistency in the findings. Methods: We conducted a systematic review and meta-analysis on the difference in the levels of HDL, LDL, TC, and triglycerides (TG) between 1) COVID-19 patients and healthy controls 2) COVID-19 patients with and without severe disease 3) COVID-19 patients who died and who survived. We included peer-reviewed articles from PubMed and Embase up to September 1, 2021. We analyzed the pooled mean differences (pMD) in lipid levels (mg/dL) for the above groups using random-effects meta-analysis and assessed publication bias using funnel plots. Results: Among the 441 articles retreived, 29 articles were included. Among them, 26 were retrospective and 3 were prospective cohorts with an aggregate of 256,721 participants. Seven studies compared lipid levels among patients with and without COVID-19, 18 studies included data on disease severity, and 9 studies reported mortality. Patients with COVID-19 had lower HDL (pMD = -6.95), and TC (pMD = -14.9) levels. There was no difference in LDL and TG levels among patients with and without COVID-19. Patients with severe COVID-19 had lower HDL (pMD = -4.4), LDL (pMD = -4.4), and TC (pMD = -10.4) levels compared to patients with non-severe disease. Patients who had lower HDL (pMD = -2.5), LDL (pMD = -10.6) and TC (pMD = -14.9) levels. TG levels did not differ with COVID-19 severity or of the above showed statistically significant publication Conclusion: Our analysis demonstrated lower lipid levels in patients with COVID-19 compared to healthy controls. Among COVID-19 patients, lower HDL, LDL, and TC levels were associated with severity and mortality. Reduced lipoprotein levels are likely secondary to systemic inflammation and hepatic dysfunction, and could be explored as potential prognostic factors in patients with COVID-19.