Serum lipids and outcomes of COVID-19 patients admitted to a tertiary hospital in Johannesburg, South Africa.

Abstract

Background: Cardiometabolic disorders contribute significantly to global cardiovascular disease risk. COVID-19 can exacerbate underlying vascular and metabolic disturbances through immune and inflammatory pathways. Lipoprotein abnormalities may influence disease susceptibility and outcomes, as lipoproteins play key roles in viral entry, inflammation and immune regulation. These markers may therefore serve as potential biomarkers for predicting outcomes, yet data from African populations remain limited.

Objective: To determine the association between admission lipid profiles and adverse clinical outcomes in hospitalised COVID-19 patients within a resource-constrained setting, in a predominantly black African population.

Methods: This retrospective observational study was conducted at Charlotte Maxeke Johannesburg Academic Hospital between 6 March and 31 August 2020. Adults aged ≥18 years with confirmed SARS-CoV-2 infection who had admission lipid profiles were included. The association between lipid parameters and adverse clinical outcomes, including intensive care unit (ICU) admission, mechanical ventilation, and in-hospital mortality, were determined by multivariable logistic regression analysis. Correlation analyses examined associations between lipids and inflammatory markers.

Results: Among 305 patients (mean (standard deviation) age 53 (13.8) years; 77% black ethnicity), non-survivors had significantly lower low-density lipoprotein cholesterol (LDL-C) and total cholesterol (TC), and higher fasting plasma glucose and inflammatory markers. Both LDL-C and TC were inversely correlated with procalcitonin (ρ=-0.44, 95% confidence interval (CI) -0.65 - -0.23, p=0.001; (ρ=-0.28, CI-0.52 - -0.05), p=0.03, respectively). Triglyceride (TG) levels were higher in ICU patients (p=0.01), and significantly correlated with an increasing white cell count (ρ=0.31, CI 0.09 - 0.53, p=0.01), neutrophil-to-lymphocyte ratio (ρ=0.27, CI 0.01 - 0.54, p=0.04) and fasting plasma glucose (ρ=0.39, CI 0.14 - 0.64, p=0.03), but were not independently predictive of mortality. High-density lipoprotein cholesterol was lower in ICU-admitted patients and inversely correlated with ferritin, but it was also not significantly associated with mortality. Lower LDL-C was an independent predictor of ICU admission (odds ratio (OR) 0.69, CI 0.50 - 0.96, p=0.03 ), mechanical ventilation (OR 0.55, CI 0.35 - 0.86, p=0.009 ) and mortality (OR 0.66, CI 0.48 - 0.91, p=0.01), with an LDL-C <2.2 mmol/L associated with increased mortality(area under curve 0.62, CI 0.55 - 0.69), as shown in receiver operating characteristic analysis.

Conclusion: Non-survivors had significantly higher inflammatory markers compared with survivors, and low LDL-C and TC were independently associated with adverse outcomes. LDL-C also predicted ICU admission, mechanical ventilation and mortality, highlighting the link between lipid metabolism and immune response. These findings emphasise the need for further prospective studies to evaluate the utility of these markers as accessible prognostic tools in low- and middle-income countries.