Graefes Arch Clin Exp Ophthalmol (2013) 251:2843–2844 DOI 10.1007/s00417-013-2486-1
LETTER TO THE EDITOR
Letter to the editor: relationship between mean platelet volume and retinopathy in patients with type 2 diabetes mellitus Ercan Varol & Mehmet Ozaydin & Fatih Aksoy
Received: 24 August 2013 / Accepted: 1 October 2013 / Published online: 18 October 2013 # Springer-Verlag Berlin Heidelberg 2013
Keywords Mean platelet volume . Diabetes mellitus . Diabetic retinopathy
Dear Editor, We read the article published by Ayhan Tuzcu et al. with great interest [1]. They have examined the mean platelet volume (MPV) in patients with type 2 diabetes mellitus. They compared MPV values in four groups according to ocular findings, as follows: group 1, diabetic patients without diabetic retinopathy; group 2, diabetic patients with non-proliferative diabetic retinopathy; group 3, diabetic patients with proliferative diabetic retinopathy; and group 4, healthy controls. They found a significant difference in MPV values between groups 2 and 4, between groups 3 and 4, and between groups 1 and 4. No significant difference was found in MPV values between groups 1 and 2 and between groups 2 and 3, whereas there was a statistically significant difference between groups 1 and 3. When the three diabetic groups (groups 1, 2, and 3) were compared with each other, while there was a statistically significant difference between groups 1 and 3, there was no significance between groups 2 and 3, and between group 1 and 2. Logistic regression analysis found a 1.40-fold increase in the risk of retinopathy development and a 1.46-fold increase in the risk of proliferative diabetic retinopathy as the MPV value increased. This is very interesting and important study. On the other hand, we would like to mention minor criticism about this study from methodological aspect. E. Varol : M. Ozaydin : F. Aksoy Department of Cardiology, Faculty of Medicine, Suleyman Demirel University, Isparta, Turkey E. Varol (*) Tip Fakultesi, Kardiyoloji ABD, Suleyman Demirel Univesitesi, Isparta, Turkey e-mail: [email protected]
Firstly, in the Methods section, the biochemical analysis part is not clear, and they did not mention the tube (EDTA or citrate) in which the blood sample was collected for whole blood count. This is very important, because MPV increases over time in EDTA-anticoagulated samples, and this increase has been shown to be proportional with the delay in time between sample collection and laboratory analysis [2]. With impedance counting, the MPV increases over time as platelets swell in EDTA, with increases of 7.9 % within 30 min having been reported and an overall increase of 13.4 % over 24 h, although the majority of this increase occurs within the first 6 h [3]. The recommended optimal measuring time of MPV is a maximum of 120 min after venipuncture. For reliable MPV measurement, the potential influence of anticoagulant on the MPV must be carefully controlled by standardizing the time delay between sampling and analysis (less than 2 h). This situation is not clear in the study. Secondly, there are significant associations of MPV with cardiovascular disorders and cardiovascular risk factors including obesity, smoking, hypertension, diabetes mellitus, prediabetes, hyperlipidemia, and metabolic syndrome [4]. They excluded hypertension, coronary artery disease, and cerebrovascular diseases. However, they didn’t mention body mass index, smoking status, blood glucose and lipid levels in patients and controls. Even prediabetes can cause a change in MPV values [5]. The difference between MPV levels might be directly due to the difference between blood glucose levels. MPV is universally available with routine blood counts by automated hemograms and a simple and easy method of assessing platelet function. In comparison to smaller ones, larger platelets have more granules, aggregate more rapidly with collagen, have higher thromboxane A2 level, and express more glycoprotein Ib and IIb/IIIa receptors [2]. Therefore, larger platelets have higher thrombotic potential and MPV is a surrogate marker of platelet activation. However, it should be kept in mind that it is influenced by many inflammatory
2844
and cardiovascular disorders and cardiovascular risk factors [6]. We believe that it would be useful if the authors provided data about these risk factors and their possible relationship with MPV. Conflict of interest The authors have no conflict of interest.
References 1. Ayhan Tuzcu E, Arıca S, Ilhan N, Daglioglu M, Coskun M, Ilhan O, Ustun I (2013) Relationship between mean platelet volume and retinopathy in patients with type 2 diabetes mellitus. Graefes Arch Clin Exp Ophthalmol. Aug 17. [Epub ahead of print]
Graefes Arch Clin Exp Ophthalmol (2013) 251:2843–2844 2. Lancé MD, Sloep M, Henskens YM, Marcus MA (2012) Mean platelet volume as a diagnostic marker for cardiovascular disease: drawbacks of preanalytical conditions and measuring techniques. Clin Appl Thromb Hemost 18(6):561–568 3. Lancé MD, van Oerle R, Henskens YM, Marcus MA (2012) Do we need time adjusted mean platelet volume measurements? Lab Hematol 16:28–31 4. Vizioli L, Muscari S, Muscari A (2009) The relationship of mean platelet volume with the risk and prognosis of cardiovascular diseases. Int J Clin Pract 63(10):1509–1515 5. Shimodaira M, Niwa T, Nakajima K, Kobayashi M, Hanyu N, Nakayama T (2013) Correlation between mean platelet volume and fasting plasma glucose levels in prediabetic and normoglycemic individuals. Cardiovasc Diabetol 12:14 6. Gasparyan AY, Ayvazyan L, Mikhailidis DP, Kitas GD (2011) Mean platelet volume: a link between thrombosis and inflammation. Curr Pharm Des 17:47–58
LETTER TO THE EDITOR
Letter to the editor: relationship between mean platelet volume and retinopathy in patients with type 2 diabetes mellitus Ercan Varol & Mehmet Ozaydin & Fatih Aksoy
Received: 24 August 2013 / Accepted: 1 October 2013 / Published online: 18 October 2013 # Springer-Verlag Berlin Heidelberg 2013
Keywords Mean platelet volume . Diabetes mellitus . Diabetic retinopathy
Dear Editor, We read the article published by Ayhan Tuzcu et al. with great interest [1]. They have examined the mean platelet volume (MPV) in patients with type 2 diabetes mellitus. They compared MPV values in four groups according to ocular findings, as follows: group 1, diabetic patients without diabetic retinopathy; group 2, diabetic patients with non-proliferative diabetic retinopathy; group 3, diabetic patients with proliferative diabetic retinopathy; and group 4, healthy controls. They found a significant difference in MPV values between groups 2 and 4, between groups 3 and 4, and between groups 1 and 4. No significant difference was found in MPV values between groups 1 and 2 and between groups 2 and 3, whereas there was a statistically significant difference between groups 1 and 3. When the three diabetic groups (groups 1, 2, and 3) were compared with each other, while there was a statistically significant difference between groups 1 and 3, there was no significance between groups 2 and 3, and between group 1 and 2. Logistic regression analysis found a 1.40-fold increase in the risk of retinopathy development and a 1.46-fold increase in the risk of proliferative diabetic retinopathy as the MPV value increased. This is very interesting and important study. On the other hand, we would like to mention minor criticism about this study from methodological aspect. E. Varol : M. Ozaydin : F. Aksoy Department of Cardiology, Faculty of Medicine, Suleyman Demirel University, Isparta, Turkey E. Varol (*) Tip Fakultesi, Kardiyoloji ABD, Suleyman Demirel Univesitesi, Isparta, Turkey e-mail: [email protected]
Firstly, in the Methods section, the biochemical analysis part is not clear, and they did not mention the tube (EDTA or citrate) in which the blood sample was collected for whole blood count. This is very important, because MPV increases over time in EDTA-anticoagulated samples, and this increase has been shown to be proportional with the delay in time between sample collection and laboratory analysis [2]. With impedance counting, the MPV increases over time as platelets swell in EDTA, with increases of 7.9 % within 30 min having been reported and an overall increase of 13.4 % over 24 h, although the majority of this increase occurs within the first 6 h [3]. The recommended optimal measuring time of MPV is a maximum of 120 min after venipuncture. For reliable MPV measurement, the potential influence of anticoagulant on the MPV must be carefully controlled by standardizing the time delay between sampling and analysis (less than 2 h). This situation is not clear in the study. Secondly, there are significant associations of MPV with cardiovascular disorders and cardiovascular risk factors including obesity, smoking, hypertension, diabetes mellitus, prediabetes, hyperlipidemia, and metabolic syndrome [4]. They excluded hypertension, coronary artery disease, and cerebrovascular diseases. However, they didn’t mention body mass index, smoking status, blood glucose and lipid levels in patients and controls. Even prediabetes can cause a change in MPV values [5]. The difference between MPV levels might be directly due to the difference between blood glucose levels. MPV is universally available with routine blood counts by automated hemograms and a simple and easy method of assessing platelet function. In comparison to smaller ones, larger platelets have more granules, aggregate more rapidly with collagen, have higher thromboxane A2 level, and express more glycoprotein Ib and IIb/IIIa receptors [2]. Therefore, larger platelets have higher thrombotic potential and MPV is a surrogate marker of platelet activation. However, it should be kept in mind that it is influenced by many inflammatory
2844
and cardiovascular disorders and cardiovascular risk factors [6]. We believe that it would be useful if the authors provided data about these risk factors and their possible relationship with MPV. Conflict of interest The authors have no conflict of interest.
References 1. Ayhan Tuzcu E, Arıca S, Ilhan N, Daglioglu M, Coskun M, Ilhan O, Ustun I (2013) Relationship between mean platelet volume and retinopathy in patients with type 2 diabetes mellitus. Graefes Arch Clin Exp Ophthalmol. Aug 17. [Epub ahead of print]
Graefes Arch Clin Exp Ophthalmol (2013) 251:2843–2844 2. Lancé MD, Sloep M, Henskens YM, Marcus MA (2012) Mean platelet volume as a diagnostic marker for cardiovascular disease: drawbacks of preanalytical conditions and measuring techniques. Clin Appl Thromb Hemost 18(6):561–568 3. Lancé MD, van Oerle R, Henskens YM, Marcus MA (2012) Do we need time adjusted mean platelet volume measurements? Lab Hematol 16:28–31 4. Vizioli L, Muscari S, Muscari A (2009) The relationship of mean platelet volume with the risk and prognosis of cardiovascular diseases. Int J Clin Pract 63(10):1509–1515 5. Shimodaira M, Niwa T, Nakajima K, Kobayashi M, Hanyu N, Nakayama T (2013) Correlation between mean platelet volume and fasting plasma glucose levels in prediabetic and normoglycemic individuals. Cardiovasc Diabetol 12:14 6. Gasparyan AY, Ayvazyan L, Mikhailidis DP, Kitas GD (2011) Mean platelet volume: a link between thrombosis and inflammation. Curr Pharm Des 17:47–58
