Decreased number and impaired functionality of endothelial progenitor cells in subjects with metabolic syndrome: Implications for increased cardiovascular risk

Abstract Objective Metabolic syndrome (MetS) is characterized by low-grade inflammation and confers an increased risk for cardiovascular disease. Endothelial progenitor cells (EPCs) are a measure of vascular health and are decreased in patients with various risk factors for cardiovascular disease (CVD). There is a paucity of data examining the EPC status especially in terms of their functionality in MetS subjects without diabetes or cardiovascular disease. We aimed to enumerate and functionally characterize EPCs in subjects with MetS in comparison to healthy controls. Methods The study was performed at the University of California Davis Medical Center. Healthy controls ( n = 31) and MetS ( n = 46) subjects were included in the study. EPCs were enumerated in fasting blood by KDR/CD34 dual positivity. Functionality was assessed by the colony forming units (CFU) assay, migration and tubule formation. Results Subjects with MetS had significantly decreased number of EPCs compared to control subjects. Furthermore, EPCs from MetS subjects depicted significantly impaired clonogenic capacity, i.e., decreased colony forming units, and impaired capacity to incorporate into tubular structures suggesting functional impairment of EPCs from MetS subjects. Conclusions We make the novel observation that MetS subjects without diabetes or CVD have decreased EPC number and impaired functionality as compared to control subjects. These findings could contribute to the increased CV risk in this population.