Clinical Research Lower Blood Vitamin D Levels Are Associated With an Increased Incidence of Contrast-Induced Nephropathy in Patients Undergoing Coronary Angiography Irfan Sahin, MD, a Baris Gungor, MD, b Mehmet Mustafa Can, MD, a Ilhan Ilker Avci, MD, a Gamze Babur Guler, MD, c Ertugrul Okuyan, MD, a Halil Biter, MD, a Suleyman Sezai Yildiz, MD, a Burak Ayca, MD, a Seckin Satilmis, MD, b and Mustafa Hakan Dinckal, MD a a Department of Cardiology, Bagcılar Research and Education Hospital, Istanbul, Turkey b Department of Cardiology, Siyami Ersek Cardiovascular and Thoracic Surgery Center, Istanbul, Turkey c Department of Cardiology, Istınye State Hospital, Istanbul, Turkey ABSTRACT Background: Vitamin D deficiency may be associated with an increased risk of renovascular disease. We assessed the correlation between vitamin D levels and contrast-induced nephropathy (CIN) in patients undergoing coronary angiography (CAG). Methods: Vitamin D and parathyroid hormone (PTH) levels were assessed before CAG in 403 patients. Estimated glomerular filtration rate (eGFR) was calculated using the Cockcroft-Gault equation. Pa- tients with eGFR < 60 mL/min/1.73 m 2 were hydrated with 0.9%- saline at 1 mL/kg/h for 12 hours before and after CAG. CIN was defined as serum creatinine increase of > 0.5 mg/dL or > 25% within 48-72 hours after CAG. Results: CIN developed in 74 participants. Baseline eGFR, blood urea and creatinine in CIN (þ) and () groups were not significantly different (P ¼ 0.14, P ¼ 0.07, and P ¼ 0.61, respectively). Total volume of contrast medium (CM) was higher in the CIN (þ) group (132  64 mL vs 90  41 mL; P ¼ 0.01). Vitamin D levels were lower (median 8.5 [range, 0.5-26.6] ng/mL vs 14.9 [range, 1.9-93.5] ng/mL; P ¼ 0.01) R  ESUM  E Introduction : Une carence en vitamine D peut être associ ee à un risque  elev e de maladie r enovasculaire. Nous avons  evalu e la corr elation entre les niveaux sanguins de vitamine D et la n ephropathie induite par les produits de contraste (NPC) chez les patients subissant une coronarographie. M ethodes : Avant de proc eder à la coronarographie, nous avons  evalu e les niveaux de vitamine D et d’hormone parathyroïdienne (HPT) chez 403 patients. L’estimation du d ebit de filtration glom erulaire (DFGe) a  et e calcul ee en utilisant la formule de Cockcroft & Gault. Les patients ayant un DFGe < 60 ml/min/1,73 m 2 ont  et e perfus e avec une solution de NaCl 0,9 % à 1 ml/kg/h pendant 12 heures avant et après la coronarographie. La NPC a  et e d etermin ee lors d’une augmentation de la cr eatinine s erique > 0,5 mg/dl ou > 25 % dans les 48-72 heures suivant la coronarographie. R esultats : La NPC s’est d evelopp ee chez 74 participants. Le DFGe basal ainsi que la concentration sanguine d’ur ee et de cr eatinine n’ont pas diff er e statistiquement entre les deux groupes NPC (þ) et (-) Contrast-induced nephropathy (CIN) is a generally revers- ible form of acute kidney injury that occurs mostly within 2- 3 days of exposure to contrast medium (CM). 1-3 The esti- mated incidence of CIN ranges from 2%-50%, and coronary angiography (CAG) or percutaneous coronary intervention (PCI), or both, are associated with CIN in about half of cases. 4-7 It accounts for 10% of all causes of hospital- acquired renal failure, results in a prolonged in-hospital stay, and represents a powerful predictor of poor early and late outcomes. 8,9 Experimental data suggest that an activated renin-angiotensin- aldosterone system, increased endothelin-1, and reactive oxygen species may play a role in the pathogenesis of CIN. Vitamin D is a potent negative regulator of the renin-angiotensin-aldosterone system and inflammation. 10 Recently, vitamin D deficiency has been shown to be associated with increased risk for renovascular disease. 11-14 Although many studies demonstrate that pre-existing renal dysfunction, diabetes mellitus, older age, and reduced left ventricular function are the most important factors for CIN, the association between vitamin D deficiency and CIN has not been investigated to date. Therefore, in this study we aimed to investigate the relationship between vitamin D deficiency and CIN in patients undergoing CAG. Received for publication December 1, 2013. Accepted December 30, 2013. Corresponding author: Dr Baris Gungor, Mehmet Akif Mah, Hicret Sok, Bulvar Sit, A Blok D 3 Umraniye/Istanbul, Turkey. Tel.: þ90-216-5458695; fax: þ90-216-4592766. E-mail: drbarisgungor@gmail.com See page 432 for disclosure information. 0828-282X/$ - see front matter Ó 2014 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.cjca.2013.12.029 Canadian Journal of Cardiology 30 (2014) 428e433