263 Letters to the Editor A higher level of IgM anti-oxidized LDL antibodies is associated with a lower severity of coronary atherosclerosis in patients on statins L. Garrido-Sánchez a,b, ⁎ , 1 , P. Chinchurreta c, 1 , E. García-Fuentes a,d , M. Mora c , F.J. Tinahones a,b a Ciber Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Spain b Servicio de Endocrinología y Nutrición, Hospital Clínico Virgen de la Victoria, Málaga, Spain c Servicio de Cardiología, Hospital Regional Universitario Carlos Haya, Málaga, Spain d Fundación IMABIS (Instituto Mediterráneo para el Avance de la Biotecnología y la Investigación Sanitaria), Málaga, Spain article info Article history: Received 23 September 2009 Accepted 27 September 2009 Available online 11 December 2009 Keywords: Statins Oxidized LDL Anti-oxidized LDL antibodies Atherosclerosis ⁎ Corresponding author. Servicio de Endocrinología y Nutrición, Hospital Clínico Virgen de la Victoria, Campus de Teatinos s/n, 29010 Málaga, Spain. Tel.: +34 951032 648; fax: +34 951 924 651. E-mail address: lourgarrido@hotmail.com (L. Garrido-Sánchez). 1 These authors collaborated equally to this work. Different studies have shown that atherosclerosis can be considered an inflammatory disease promoted by ongoing inflammatory responses and immune reactions occurring in the vessel wall [1]. Increased oxidative stress gives rise to oxidation-specific neo-epitopes on LDL, which induce an immune response resulting in the formation of antibodies against oxidized LDL [2]. Although several studies have found an association between these anti-oxidized LDL antibodies and atherosclerosis, the clinical importance of these autoantibodies is still under discussion [3]. Whereas some studies have shown that these antibodies contribute to disease [4], others have found they contribute to protection [5]. Statins are one of the treatments used to lower concentrations of LDL cholesterol, thereby reducing the risk of cardiovascular disease and atherosclerosis [6]. Statins have been shown to possess an antioxidative action, protecting the LDL from oxidization and further reducing the progression of atherosclerosis [7]. An association has also been found between the levels of anti-oxidized LDL antibodies, the oxidative modification of LDL and treatment with statins [8]. Thus, the aim of this study was to determine whether levels of anti-oxidized LDL antibodies are associated with the presence of multivessel coronary artery disease in a group of patients undergoing invasive coronary angiography depending on whether they were or were not taking statins. The study included a group of 236 patients who underwent invasive coronary angiography with quantification of the coronary atherosclero- tic lesions in the different coronary segments by the Haemodynamics Unit of the Cardiology Service of Carlos Haya Regional University Hospital. The patients were placed into two groups, according to whether they were (n =118) or were not (n =118) taking statins. Measurements were made of IgM and IgG anti-oxidized LDL antibodies. The results of our study showed that within the group of patients who were taking statins, the percentage of patients with IgM anti-oxidized LDL antibodies below 50th percentile was significantly higher in those with multivessel coronary artery disease than in those without multivessel coronary artery disease (57.4% vs. 37.5%, P b 0.05). No significant differences were found in the distribution of the patients according to their levels of IgG anti-oxidized LDL antibodies (57.4% vs. 45.8%, P =0.214). A logistic regression model in the group receiving statins showed that the variable that was significantly associated with the presence of multivessel coronary artery disease was the level of IgM anti- oxidized LDL antibodies (Beta Coefficient =-28.738, P = 0.008). No significant differences were found in the distribution of the patients within the group who were not taking statins, according to the presence of multivessel coronary artery disease (data no show). The patients were later grouped according to the number of diseased coronary arteries (0, 1–2, 3–4 or ≥5 diseased coronary arteries). The IgM anti-oxidized LDL antibodies declined significantly as the number of diseased arteries increased (P b 0.05) (Fig. 1). The main finding of this study shows that patients with multivessel coronary artery disease who are being treated with statins had lower levels of IgM anti-oxidized LDL antibodies. Our results showed that levels of IgM anti-oxidized LDL antibodies fell as the number of diseased coronary arteries rose, with no significant differences in the levels of IgG anti-oxidized LDL antibodies. These findings coincide with those of others, who found a negative association with IgM anti-oxidized LDL antibodies [5]. Other studies have shown that plasma levels of anti-oxidized LDL antibodies are decreased in Fig. 1. Levels of IgM anti-oxidized LDL antibodies according to the number of diseased coronary arteries. Different letters indicate significant differences between the means of the different groups of subjects (P b 0.05).