DIABETICMedicine DOI: 10.1111/j.1464-5491.2008.02649.x © 2009 The Authors. 134 Journal compilation © 2009 Diabetes UK. Diabetic Medicine, 26, 134–141 Blackwell Publishing Ltd Original Article: Complications Complications impaired endothelial progenitor cell function in Type 2 diabetic patients with or without critical leg ischaemia: implication for impaired neovascularization in diabetes M.-C. Chen, J.-J. Sheu*, P.-W. Wang†, C.-Y. Chen†, M.-C. Kuo†, C.-J. Hsieh†, J.-F. Chen† and H.-W. Chang‡ Division of Cardiology, Department of Internal Medicine, *Division of Cardiovascular Surgery, Department of Surgery, †Division of Metabolism and Endocrine, Chang Gung Memorial Hospital–Kaohsiung Medical Center, Chang Gung University College of Medicine and ‡Department of Biological Sciences, National Sun Yat-Sen University, Taiwan Accepted 21 November 2008 Abstract Aims This study tested the hypothesis that migratory function of endothelial progenitor cells (EPCs) is impaired in Type 2 diabetic patients with or without critical leg ischaemia. Methods Seventy-four patients were classified into four groups: Type 2 diabetic (n = 21) and non-diabetic patients (n = 10) with critical leg ischaemia and Type 2 diabetic patients without lower extremity vascular disease (n = 30) and healthy subjects (n = 13). The number and functional activity of circulating and cultured EPCs were determined. Results The migratory function of cultured EPCs was significantly impaired in diabetic patients without (median, 48, interquartile range, 46, 49 count/view/well) and with (median, 51, interquartile range, 46, 60 count/view/well) critical leg ischaemia and non-diabetic patients with critical leg ischaemia (median, 49, interquartile range, 47, 55 count/view/well) compared with healthy subjects (median, 63, interquartile range, 57, 65 count/view/well) (P < 0.0001). The number of circulating EPCs was lower in Type 2 diabetic patients without lower extremity vascular disease (median, 3500, inter- quartile range, 1600, 6600/10 6 cytometric events) than Type 2 diabetic patients with critical leg ischaemia (median, 5300, interquartile range, 2400, 11 100/10 6 cytometric events), non-diabetic patients with critical leg ischaemia (median, 5550, interquartile range, 2000, 32 100/10 6 cytometric events) and healthy subjects (median, 5400, interquartile range, 2700, 8700/10 6 cytometric events) (P = 0.413). Conclusions The migratory function of EPCs is impaired in patients with Type 2 diabetes, even in those without critical leg ischaemia. These findings present an important new insight into the pathogenesis of impaired neovascularization and critical limb ischaemia in diabetic patients and provide avenues of future clinical study. Diabet. Med. 26, 134–141 (2009) Keywords diabetes, leg ischaemia, stem cells Abbreviations DiLDL, 1,19-dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine-labelled acetylated low-density lipoprotein; EPCs, endothelial progenitor cells; EPO, erythropoietin; FITC, fluorescein isothiocyanate; GMCSF, granulocyte macrophage colony stimulating factor; TNF-α, tumour necrosis factor alpha; VEGF, vascular endothelial growth factor Introduction Critical leg ischaemia is a common cause of hospital admission in patients with Type 2 diabetes mellitus and leads to a sig- nificant rate of limb loss. The precise mechanisms of critical limb ischaemia in patients with Type 2 diabetes mellitus remain poorly understood. Stimulation of neovascularization is a Correspondence to: Mien-Cheng Chen MD, Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital–Kaohsiung Medical Center, Chang Gung University College of Medicine, 123, Ta Pei Road, Niao Sung Hsiang, Kaohsiung Hsien 83301, Taiwan. E-mail: chenmien@ms76.hinet.net