Lai YC, et al. - In the Multi-Ethnic Study of Atherosclerosis (MESA), researchers explored the connection between plasma lipids and white blood cell counts (basophils, eosinophils, monocytes, neutrophils and lymphocytes). The study involved 2,873 candidates from MESA with a complete white blood count and differential analysis. By multivariable linear regression, the cross-sectional connection of total cholesterol, LDL cholesterol, HDL cholesterol and triglyceride levels with different white blood cell counts has been analyzed. A 1-SD increment in total cholesterol and LDL cholesterol correlated 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, after adjusting for sociodemographic and confounding factors, CVD risk factors, other lipid measures, and multiple testing correction. A 1-SD increment increase in HDL cholesterol correlated with a 1.5% lower white blood cell count but was not significantly related to changes in any individual cell type. While significant associations between plasma lipid levels and white blood cell populations were seen, the varied and modest nature of these associations makes supporting the premise that lipids are in the causal pathway of human leukogenesis difficult.