CLB-08690; No. of page: 1; 4C: Clinical Biochemistry xxx (2014) xxx
Contents lists available at ScienceDirect
Clinical Biochemistry journal homepage: www.elsevier.com/locate/clinbiochem
Letter to the Editor The association of red cell distribution width and morbid obesity In a recent issue of Clinical Biochemistry (published online), we read with great interest the published article by Vaya et al. entitled “Red blood cell distribution width is not related with inflammatory parameters in morbidly obese patients” [1]. They have shown that red cell distribution width (RDW) values were higher in obese patients than in normo-weight controls, along with C-reactive protein and fibrinogen, while hemoglobin, serum iron, MCH and MCHC were lower in morbidly obese patients. The elevated RDW values in morbidly obese patients reflect a mild red blood cell hypochromia that does not relate to inflammatory parameters. This study is instructive because it provides scientific information on this clinically relevant condition. However, we would like to make some comments with respect to the authors' interpretations of biochemical markers. RDW represents the variability of the red blood cell volume distribution and can be considered an index of heterogeneity in size of circulating erythrocytes [2]. This parameter can be measured easily and reported as a component of complete blood count by automated hematology analyzers. In their paper, authors have excluded patients with organic, malignant, hematological, infectious and inflammatory disease, or previous history of ischemic heart disease, stroke, thromboembolism, treatment with rheological drugs, and secondary obesity such as hypothyroidism. However, the RDW levels may also reflect neurohumoral activation, nutritional deficiencies of folate and vitamin B12, bone marrow dysfunction, and some medications [3,4]. Furthermore, the RDW levels are also elevated in thrombotic thrombocytopenic purpura [2]. Patients with these conditions are mostly excluded from the studies which are showing the prognostic value of the RDW [2]. The authors investigated to explore the relationship of RDW with morbid obesity. The results of their study show that RDW is higher in morbidly obese patients compared to controls [1]. However, authors only measured hemoglobin, hematocrit, mean corpuscular volume (MCV), and RDW levels. They did not measure other factors including
vitamin B12 and folate levels. These parameters could provide more accurate information to explore the relationship between RDW and morbid obesity. Additionally, platelet count values should be stated in their paper to demonstrate the elimination of thrombocytopenic diseases. In conclusion, the explanation of these concerns will certainly provide clearer information for the readers. References [1] Vaya A, Alis R, Hernandez-Mijares A, Sola E, Camara R, Rivera L, et al. Red blood cell distribution width is not related with inflammatory parameters in morbidly obese patients. Clin Biochem Feb 1 2014. http://dx.doi.org/10.1016/j.clinbiochem.2014.01.020 [Epub ahead of print]. [2] Yaman H, Celik T, Akgul EO, Cayci T, Kurt Y. Red cell distribution width and acute coronary syndromes. Int J Cardiol 2010;145(2):353. [3] Balta S, Demirkol S, Arslan Z, Unlu M, Celik T. Inflammatory status as a major role of risk factor for atrial fibrillation. J Thromb Thrombolysis 2014;37(4):540–1. [4] Fici F, Celik T, Balta S, Iyisoy A, Unlu M, Demitkol S, et al. Comparative effects of nebivolol and metoprolol on red cell distribution width and neutrophil/lymphocyte ratio in patients with newly diagnosed essential hypertension. J Cardiovasc Pharmacol 2013;62:388–93.
Ibrahim Aydin Department of Biochemistry, Sarikamis Military Hospital, Sarikamis, Kars, Turkey Corresponding author. E-mail address: [email protected]. Fevzi Nuri Aydin Department of Biochemistry, Sirnak Military Hospital, Sirnak, Turkey Mehmet Agilli Department of Biochemistry, Agri Military Hospital, Agri, Turkey 14 March 2014 Available online xxxx
http://dx.doi.org/10.1016/j.clinbiochem.2014.04.011 0009-9120/© 2014 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.
Please cite this article as: Aydin I, et al, The association of red cell distribution width and morbid obesity, Clin Biochem (2014), http://dx.doi.org/ 10.1016/j.clinbiochem.2014.04.011
Contents lists available at ScienceDirect
Clinical Biochemistry journal homepage: www.elsevier.com/locate/clinbiochem
Letter to the Editor The association of red cell distribution width and morbid obesity In a recent issue of Clinical Biochemistry (published online), we read with great interest the published article by Vaya et al. entitled “Red blood cell distribution width is not related with inflammatory parameters in morbidly obese patients” [1]. They have shown that red cell distribution width (RDW) values were higher in obese patients than in normo-weight controls, along with C-reactive protein and fibrinogen, while hemoglobin, serum iron, MCH and MCHC were lower in morbidly obese patients. The elevated RDW values in morbidly obese patients reflect a mild red blood cell hypochromia that does not relate to inflammatory parameters. This study is instructive because it provides scientific information on this clinically relevant condition. However, we would like to make some comments with respect to the authors' interpretations of biochemical markers. RDW represents the variability of the red blood cell volume distribution and can be considered an index of heterogeneity in size of circulating erythrocytes [2]. This parameter can be measured easily and reported as a component of complete blood count by automated hematology analyzers. In their paper, authors have excluded patients with organic, malignant, hematological, infectious and inflammatory disease, or previous history of ischemic heart disease, stroke, thromboembolism, treatment with rheological drugs, and secondary obesity such as hypothyroidism. However, the RDW levels may also reflect neurohumoral activation, nutritional deficiencies of folate and vitamin B12, bone marrow dysfunction, and some medications [3,4]. Furthermore, the RDW levels are also elevated in thrombotic thrombocytopenic purpura [2]. Patients with these conditions are mostly excluded from the studies which are showing the prognostic value of the RDW [2]. The authors investigated to explore the relationship of RDW with morbid obesity. The results of their study show that RDW is higher in morbidly obese patients compared to controls [1]. However, authors only measured hemoglobin, hematocrit, mean corpuscular volume (MCV), and RDW levels. They did not measure other factors including
vitamin B12 and folate levels. These parameters could provide more accurate information to explore the relationship between RDW and morbid obesity. Additionally, platelet count values should be stated in their paper to demonstrate the elimination of thrombocytopenic diseases. In conclusion, the explanation of these concerns will certainly provide clearer information for the readers. References [1] Vaya A, Alis R, Hernandez-Mijares A, Sola E, Camara R, Rivera L, et al. Red blood cell distribution width is not related with inflammatory parameters in morbidly obese patients. Clin Biochem Feb 1 2014. http://dx.doi.org/10.1016/j.clinbiochem.2014.01.020 [Epub ahead of print]. [2] Yaman H, Celik T, Akgul EO, Cayci T, Kurt Y. Red cell distribution width and acute coronary syndromes. Int J Cardiol 2010;145(2):353. [3] Balta S, Demirkol S, Arslan Z, Unlu M, Celik T. Inflammatory status as a major role of risk factor for atrial fibrillation. J Thromb Thrombolysis 2014;37(4):540–1. [4] Fici F, Celik T, Balta S, Iyisoy A, Unlu M, Demitkol S, et al. Comparative effects of nebivolol and metoprolol on red cell distribution width and neutrophil/lymphocyte ratio in patients with newly diagnosed essential hypertension. J Cardiovasc Pharmacol 2013;62:388–93.
Ibrahim Aydin Department of Biochemistry, Sarikamis Military Hospital, Sarikamis, Kars, Turkey Corresponding author. E-mail address: [email protected]. Fevzi Nuri Aydin Department of Biochemistry, Sirnak Military Hospital, Sirnak, Turkey Mehmet Agilli Department of Biochemistry, Agri Military Hospital, Agri, Turkey 14 March 2014 Available online xxxx
http://dx.doi.org/10.1016/j.clinbiochem.2014.04.011 0009-9120/© 2014 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.
Please cite this article as: Aydin I, et al, The association of red cell distribution width and morbid obesity, Clin Biochem (2014), http://dx.doi.org/ 10.1016/j.clinbiochem.2014.04.011
