Monocyte heterogeneity in obesity and subclinical atherosclerosis

Department of Internal Medicine IV, Saarland University Hospital, Homburg 66421, Germany.
European Heart Journal (Impact Factor: 14.72). 09/2009; 31(3):369-76. DOI: 10.1093/eurheartj/ehp308
Source: PubMed

ABSTRACT AIMS: Monocytes and monocyte-derived macrophages have been recognised as the cellular hallmark of atherosclerosis decades ago. Recently, they have also been shown to play a pivotal role in obesity. Monocytes display immunophenotypic heterogeneity with functionally distinct subpopulations. We initiated the I LIKE HOMe study to examine monocyte heterogeneity in obesity and subclinical atherosclerosis. METHODS AND RESULTS: We assessed carotid intima media thickness (IMT), body mass index (BMI), and other cardiovascular risk factors in 622 healthy volunteers. Using flow-cytometry, we differentiated monocytes into CD14(++)CD16(-) and CD16(+) cells, which we further subdivided into CD14(++)CD16(+) and CD14((+))CD16(+) cells. Body mass index was significantly correlated with carotid IMT. High CD16(+) monocyte counts were significantly associated with both higher BMI and increased carotid IMT. Adjustment for CD16(+) monocyte counts weakened the correlation between BMI and carotid IMT, suggesting that the increase in CD16(+) monocyte numbers in obesity may partly explain the association between obesity and IMT. Conclusion: Our results reveal a significant univariate association between CD16(+) monocytes and both obesity and subclinical atherosclerosis in low-risk individuals. They are in line with recent observations that CD16(+) monocytes show high endothelial affinity and a potent capacity to invade vascular lesions and to transform into pro-inflammatory cytokine producing macrophages.

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