INTRODUCTION: The present study investigates the effect of 25-OH vitamin D replacement on blood pressure, as well as biochemical and IL-12 parameters in patients with metabolic syndrome (MetS), and whether a threshold for vitamin D exists in such effect.
METHODS: This prospective study included 44 metabolic syndrome patients who presented to the Internal Medicine Clinic of Haydarpaşa Numune Training and Research Hospital. The patients had a mean age of 44.68±11.49 years; 65.9% (n=29) were female and 34.1% (n=15) were male. Biochemical tests were made for 25-OH vitamin D, glucose, HbA1c, triglycerides, HDL-K, LDL-K, BUN, creatinine, uric acid, calcium, albumin, leukocytes, neutrophils, lymphocytes, hemoglobin, C-reactive protein, and spot urine albumin/creatinine ratio, and blood pressure measurements were made before and after vitamin D replacement. In addition, IL-12 levels were measured twice using the ELISA method. A statistical analysis of the data was made using IBM the SPSS Statistics 22 (IBM SPSS, Türkiye) software package.
RESULTS: A statistically significant decrease was noted in systolic and diastolic blood pressure and IL-12 levels after vitamin D re-placement when compared to the pre-replacement levels (p<0.001, p=0.008, p<0.001). When the patients were divided into two groups based on 25-OH vitamin D levels (Group-1, 25-OH vitamin D ≥32 ng/mL; Group-2, 25-OH vitamin D <32 ng/mL) after vitamin D replacement, the mean IL-12 level was found to be significantly lower in the Group-1 patients than in the Group-2 patients (p<0.033). In addition, a positive correlation was identified between vitamin D replacement and serum levels of magnesium.
DISCUSSION AND CONCLUSION: These findings suggested that vitamin D replacement had blood pressure-lowering and anti-inflammatory effects in MetS patients. The threshold for the anti-inflammatory effect was found to be ≥32 ng/mL.