Links between concentrations of serum 25-hydroxyvitamin D3 and the numbers of circulating progenitor mononuclear cells in patients with metabolic syndrome

Background: Evidence points to the pivotal role of vitamin D in the pathogenesis of metabolic syndrome (MetS), including deterioration of the endogenous endothelial repair system. Objectives: This study was conducted to investigate links between serum 25-hydroxyvitamin D3 (25(OH)3D) concentrations and the numbers of circulating progenitor mononuclear cells in MetS individuals. Methods: The cross-sectional study involved 47 patients with MetS. The circulating level of 25(OH)D3 and other biomarkers were measured at the start of the study. The number of mononuclear progenitor cells was determined using the flow cytometric technique (FCT). Results: MetS patients from the entire group of 47 patients were divided into four cohorts depending on 25(OH)D3 levels. The groups comprised patients with 25(OH)D3 levels above 100 nmol/L (n = 10), patients with levels from 50 to 100 nmol/L (n = 12), patients with levels from 30 to 50 nmol/L (n = 14), and patients with levels below 30 nmol/L (n = 11). There were significant differences between the MetS cohorts in terms of haemoglobin A1c (HbA1c) (P = 0.038), the homeostasis model assessment for insulin resistance (HOMA-IR) (P = 0.042), triglycerides (P = 0.044), osteoprotegerin (P=0.028), adiponectin (P = 0.018), high density lipoprotein cholesterol (HDL-C) (P=0.036), and CD14+D309+Tie-2+ cells. Vitamin D deficiency in a multivariate log-linear regression model appeared to be an independent predictor of the numbers of CD14+D309+ Tie-2+ cells (OR 1.12; 95% CI 1.06 to 1.19; P = 0.002). Osteoprotegerin, high sensitivity C-reactive protein (hs-CRP), and adiponectin have been shown to make an independent impact on the numbers of CD14+D309+ Tie-2+ cells. Using C-statistics, we found that the use of three biomarkers (osteoprotegerin, hs-CRP, and adiponectin) can significantly improve a predictive model based on vitamin D deficiency for decreased numbers of CD14+ D309+Tie-2+ cells. Conclusions: We found that low levels of 25(OH)D3 were associated with depleted numbers of proangiogenic progenitor mononuclear cells in MetS patients