Association of lipid metabolism with pneumonia risk in under-five children in China

OBJECTIVE: The relationship between lipid metabolism and pneumonia in under-five children remains unclear. The aim of the study was to explore the association of several lipids, lipoproteins and apolipoproteins with the risk of childhood pneumonia, and to initially reveal the mechanisms involved. METHODS: There were 1000 children with confirmed severe pneumonia and 1000 healthy controls (18–59 months old) in the study. Serum levels of several lipids, lipoproteins and apolipoproteins were measured. The occurrence of hypoxaemia and serum level of C-reactive protein were recorded. Multivariate logistic regression and spearman correlation analysis were adopted to assess the correlation between these variables to achieve the research objective. RESULTS: First, higher triglycerides, total cholesterol, LDL cholesterol, VLDL cholesterol and apolipoprotein B levels were associated with the elevated risk of severe pneumonia (OR: 1.407, 95%CI: 1.336∼1.480; OR: 1.947, 95%CI: 1.741∼2.175; OR: 1.153, 95%CI: 1.116∼1.189; OR: 1.310, 95%CI: 1.222∼1.404; OR: 1.075, 95%CI: 1.003∼1.151). Higher HDL cholesterol and apolipoprotein A1 levels were associated with a decreased risk of the disease (OR: 0.903, 95%CI: 0.873∼0.933; OR: 0.921, 95%CI: 0.891∼0.952). Second, higher triglycerides level was associated with an increased risk of hypoxemia in these children (OR: 1.142, 95%CI: 1.072∼1.215). Third, serum HDL cholesterol level was linearly associated with C-reactive protein level in these children (ρ = -0.343, P < 0.001). CONCLUSION: Abnormal levels of several lipids, lipoproteins and apolipoproteins were related to severe childhood pneumonia. The findings that triglycerides and HDL cholesterol were respectively implicated in hypoxaemia and inflammation might partly explain the mechanisms linking lipid metabolism to severe pneumonia.