The association of plasma lipids with white blood cell counts: Results from the Multi-Ethnic Study of Atherosclerosis

Background: Previous studies have demonstrated that elevated cholesterol results in increased white blood cell counts in mouse models. However, there is insufficient evidence to support this in humans. Objective: The objective of the study was to investigate the relationship of plasma lipids with white blood cell counts (basophils, eosinophils, monocytes, neutrophils and lymphocytes) in the Multi-Ethnic Study of Atherosclerosis. Methods: The analysis included 2873 Multi-Ethnic Study of Atherosclerosis participants with a complete white blood count and differential analysis. The cross-sectional association of total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglyceride levels with different white blood cell counts was analyzed by multivariable linear regression. Results: After adjusting for sociodemographic and confounding factors including red blood cell counts, platelet counts, use of lipid-lowering medication, cardiovascular disease risk factors and other lipid measures, and multiple testing correction, a one–standard deviation increment in total cholesterol and low-density lipoprotein cholesterol was associated with 2.8% and 2.3% lower total white blood cell counts, 3.7% and 3.0% lower monocyte counts, and 3.4% and 2.7% lower neutrophil counts (all P < .01). The same increment in logarithm-transformed triglyceride levels was associated with 2.3% higher total white blood cell counts and 4.5% higher lymphocyte counts (both P < .001). Similar results were obtained after excluding participants taking lipid-lowering medication. A one–standard deviation increase in high-density lipoprotein cholesterol was associated with a 1.5% lower white blood cell count (P = .018) but was not significantly associated with changes in any individual cell type. Conclusion: While significant associations were observed between plasma lipid levels and white blood cell populations, the heterogeneous and modest nature of these relationships