Tarcin Ozlem, Yavuz Dilek Gogas, Ozben Beste, Telli Ahu, Ogunc Ayliz Velioglu, Yuksel Meral, Toprak Ahmet, Yazici Dilek, Sancak Seda, Deyneli Oguzhan, Akalin Sema
Section of Endocrinology and Metabolism, Marmara University School of Medicine, 34060 Istanbul, Turkey.
J Clin Endocrinol Metab. 2009 Oct;94(10):4023-30. doi: 10.1210/jc.2008-1212. Epub 2009 Jul 7.
Vitamin D receptors are present in many tissues. Hypovitaminosis D is considered to be a risk factor for atherosclerosis.
This study explores the effects of vitamin D replacement on insulin sensitivity, endothelial function, inflammation, oxidative stress, and leptin in vitamin D-deficient subjects.
DESIGN, SETTING, AND PATIENTS: Twenty-three asymptomatic vitamin D-deficient subjects with 25-hydroxyvitamin D [25(OH)D] levels below 25 nmol/liter were compared with a control group that had a mean 25(OH)D level of 75 nmol/liter. The vitamin D-deficient group received 300,000 IU im monthly for 3 months. The following parameters were evaluated before and after treatment: vitamin D metabolites, leptin, endothelial function by brachial artery flow mediated dilatation (FMD), insulin sensitivity index based on oral glucose tolerance test, and lipid peroxidation as measures of thiobarbituric acid reactive substances (TBARS).
FMD measurements were significantly lower in 25(OH)D-deficient subjects than controls (P = 0.001) and improved after replacement therapy (P = 0.002). Posttreatment values of TBARS were significantly lower than pretreatment levels (P < 0.001). A positive correlation between FMD and 25(OH)D (r = 0.45; P = 0.001) and a negative correlation between FMD and TBARS (r = -0.28; P < 0.05) were observed. There was a significant increase in leptin levels after therapy, and the leptin levels were positively correlated with 25(OH)D levels (r = 0.45; P < 0.05).
This study shows that 25(OH)D deficiency is associated with endothelial dysfunction and increased lipid peroxidation. Replacement of vitamin D has favorable effects on endothelial function. Vitamin D deficiency can be seen as an independent risk factor of atherosclerosis. Hypovitaminosis D-associated endothelial dysfunction may predispose to higher rates of cardiovascular disease in the winter.
维生素D受体存在于许多组织中。维生素D缺乏被认为是动脉粥样硬化的一个危险因素。
本研究探讨维生素D补充对维生素D缺乏受试者的胰岛素敏感性、内皮功能、炎症、氧化应激和瘦素的影响。
设计、地点和患者：将23名无症状的维生素D缺乏受试者（25-羟维生素D[25(OH)D]水平低于25 nmol/升）与平均25(OH)D水平为75 nmol/升的对照组进行比较。维生素D缺乏组每月接受300,000 IU肌肉注射，共3个月。在治疗前后评估以下参数：维生素D代谢物、瘦素、通过肱动脉血流介导的扩张（FMD）评估的内皮功能、基于口服葡萄糖耐量试验的胰岛素敏感性指数以及作为硫代巴比妥酸反应性物质（TBARS）测量指标的脂质过氧化。
25(OH)D缺乏受试者的FMD测量值显著低于对照组（P = 0.001），补充治疗后有所改善（P = 0.002）。TBARS的治疗后值显著低于治疗前水平（P < 0.001）。观察到FMD与25(OH)D之间呈正相关（r = 0.45；P = 0.001），FMD与TBARS之间呈负相关（r = -0.28；P < 0.05）。治疗后瘦素水平显著升高，且瘦素水平与25(OH)D水平呈正相关（r = 0.45；P < 0.05）。
本研究表明，25(OH)D缺乏与内皮功能障碍和脂质过氧化增加有关。补充维生素D对内皮功能有有益影响。维生素D缺乏可被视为动脉粥样硬化的独立危险因素。维生素D缺乏相关的内皮功能障碍可能使冬季心血管疾病的发生率更高。
