No effect of vitamin D administration plus dietary intervention on emerging cardiovascular risk factors in patients with metabolic syndrome

Background: Patients with metabolic syndrome (MetS) have low serum 25-hydroxyvitamin D (25(OH)VitD) levels. Low 25(OH)VitD has been associated with several emerging cardiovascular disease (CVD) risk factors, while VitD administration may ameliorate them. Aim: To study the effect of 25(OH)VitD supplementation plus dietary instructions on novel CVD risk factors in MetS patients. Methods: This is a pre-specified analysis of a previously published study. Patients with MetS (n = 50, 52 ± 10 years) were given dietary instructions and were randomized to receive either 25(OH)VitD, 2.000 IU/day p.o. (Suppl group) or nothing (No-Suppl group). Serum 25(OH)VitD, small dense low-density lipoprotein cholesterol (sdLDL), as well as lipoprotein-associated phospholipase A2 (LpPLA2) activity, leptin and adiponectin levels were measured at baseline and 3 months later. Results: In the Suppl group 25(OH)VitD levels increased by 90% [from 16.1 (3.3–35.1) to 30.6 (8.4–67.6) ng/mL, p = 0.001] and by 33.3% [from 9.9 (4.0–39.6) to 13.2 (3.5–36.8) ng/mL, p = NS] in the No-Suppl group. sdLDL serum levels, mean LDL size, LpPLA2 activity, leptin, adiponectin concentration and leptin to adiponectin ratio did not change significantly in both groups. Conclusion: In this small study the administration of 25(OH)VitD plus dietary intervention in patients with MetS were not associated with any significant change in various emerging CVD risk factors. (NCT01237769 ClinicalTrials.gov). Keywords: Metabolic syndrome, 25(OH)VitD, Small dense low-density lipoprotein cholesterol, Lipoprotein-associated phospholipase A2, Leptin, Adiponectin