EFFECT OF VITAMIN D REPLACEMENT ON SERUM LIPOPROTEIN FUNCTIONALITY IN HEALTHY PRE-MENOPAUSAL WOMEN

Aim: Low vitamin D (vitD) status has been linked to increased cardiovascular (CV) risk. Serum HDL cholesterol efflux capacity (CEC) is a metric of HDL functionality that is inversely correlated to CV risk, independently of HDL-cholesterol (HDL-C) plasma levels. In the present work we evaluated the effect of vitD replacement on:) HDL CEC; 3) serum cholesterol loading capacity (CLC), as index of its pro-atherogenic potential. Material and Methods: Healthy pre-menopausal women (n=31) with vitD levels <20 ng/mL, status defined as vitamin D deficient, were enrolled for the study and scheduled for vitD replacement. Flow-mediated dilatation (FMD) and pulse wave velocity (PWV) were measured by standard techniques as markers of subclinical atherosclerosis. HDL CEC was assessed by radioisotopic technique while serum Serum CLC was measured by a fluorimetric assay. Sera adipokines levels were analysed by ELISA kit. Results: No differences were found at baseline and after replacement in total cholesterol, HDL cholesterol, LDL cholesterol and triglyceride levels. Markers of subclinical atherosclerosis were significantly improved after vitD replacement with an increased in FMD (10,32%± 1,2 vs 10,01%± 1,2 p<0.0001) and a reduction of PWV (5,4m/s ± 0,8 vs 5,6m/s ± 0,9 p<0.0001) compared to baseline. Total and ABCA1-mediated CEC were increased after vitD replacement compared to baseline (+19,44% p=0.003 and +70,8% p=0.0008 respectively), while no difference was found in ABCG1-mediated CEC. Serum CLC was significantly decreased after vitD replacement as compared to baseline (-13,35% p=0.02). After vitD replacement, adiponectin concentrations increased (+50,56% p<0.0001) while resistin decreased (-24,33% p<0.0001); moreover after vitD replacement, changes of resistin levels were inversely associated with total and ABCA1- mediated CEC (r=-0,326 p=0.07 and r=-0,469 p=0.009 respectively). Conclusions: VitD status influences circulating lipoprotein functions relevant for atherosclerosis in healthy pre-menopausal women which may be involved in the association between vitD status and CV risk.