ABSTRACT
OBJECTIVES: Recent research has shown that hypovitaminosis D may increase the risk of hypertension, vascular disease, diabetes mellitus, obesity and Metabolic Syndrome (MetS). Endothelial Dysfunction (ED) is one of the key components of MetS which is associated with an imbalance between vasoactive substances such as Nitric Oxide (NO) and Endothelins (ET). In this study, we assessed the association of 25(OH) D3 level with endothelial dysfunction and subclinical atherosclerosis in MetS patients. DESIGN AND METHODS: 105 MetS patients and 48 controls were included. 25(OH) D3 levels were measured using Ultra-High Performance Liquid Chromatography (UHPLC). NOx (NO2 plus NO3) and Endothelin- 1(ET-1) concentrations were determined along with routine biochemical tests. Flow-Mediated Dilatation (FMD) and carotid Intima-Media Thickness (cIMT) were measured by ultrasonography. RESULTS: In MetS patients, vitamin D and NOx levels were significantly lower (p<0.001), while ET-1 levels were higher than controls (p<0.005). MetS patients with ED exhibited significantly lower vitamin D levels than their counterparts free of ED. Vitamin D levels were correlated positively with FMD and NOx, and negatively with systolic blood pressure and body mass index. Subclinical atherosclerosis as assessed by the cIMT did not associate with low vitamin D levels. CONCLUSION: Vitamin D deficiency seen in MetS patients is more prominent in the presence of ED. Hypovitaminosis D may affect endothelial cells, and participate in the development of hypertension.
Subject(s)
Atherosclerosis/complications , Endothelium, Vascular/physiopathology , Metabolic Syndrome/complications , Vasodilation , Vitamin D Deficiency/complications , Adult , Asymptomatic Diseases , Atherosclerosis/blood , Atherosclerosis/diagnostic imaging , Atherosclerosis/physiopathology , Biomarkers/blood , Calcifediol/blood , Carotid Intima-Media Thickness , Case-Control Studies , Chromatography, High Pressure Liquid , Endothelin-1/blood , Endothelium, Vascular/diagnostic imaging , Endothelium, Vascular/metabolism , Female , Humans , Male , Metabolic Syndrome/blood , Metabolic Syndrome/diagnosis , Metabolic Syndrome/physiopathology , Middle Aged , Nitrates/blood , Nitrites/blood , Prognosis , Risk Factors , Vitamin D Deficiency/blood , Vitamin D Deficiency/diagnosis , Vitamin D Deficiency/physiopathologyABSTRACT
BACKGROUND: In individuals with atherosclerotic risk factors, endothelial dysfunction (ED) appears as an early phase in the development of clinical symptoms. Recent studies indicate that adropin, a newly identified peptide, participates in cardiovascular health through the regulation of several metabolic events including angiogenesis and blood flow. In this study, we aimed to determine the relation of adropin with biochemical and radiologic parameters which reflect ED such as endothelial nitric oxide synthase (eNOS), endothelin 1 (ET-1), nitric oxide (NO) and flow-mediated dilatation (FMD) along with the routine biochemical measurements in patients recently diagnosed with metabolic syndrome (MetS). METHODS: Fasting blood samples from 110 patients with MetS diagnosed according to the NCEP ATP III-2005 criteria were collected to measure the concentrations of adropin and other parameters including the lipid profile, insulin and glucose. Serum NOx concentrations were determined by measuring NO2 plus NO3. FMD test was performed by ultrasonography, and patients were stratified as FMD (+) or (-). Data were compared between these two subgroups and also with matching healthy controls (n=50). Biochemical data were evaluated using Student's t or Mann-Whitney U tests. RESULTS: Fifty-nine subjects had ED (+) and the remaining 101 subjects were ED (-). In the first group, adropin levels were significantly lower than the latter (2.13±1.05 vs. 3.41±1.63 ng/mL, respectively; p<0.001) and independently associated with FMD positivity as assessed by the logistic regression analysis. CONCLUSIONS: Low adropin level in circulation is related to ED and has a close association with FMD. Any alterations in its level may be of help in order to assess the development of ED before the occurrence of clinical symptoms in patients with metabolic syndrome.
