2298 The Journal of Rheumatology 2009; 36:10; doi:10.3899/jrheum.090282 Personal non-commercial use only. The Journal of Rheumatology Copyright © 2009. All rights reserved. Metabolic Syndrome and the Incidence of Symptomatic Deep Vein Thrombosis Following Total Knee Arthroplasty RAJIV GANDHI, FAHAD RAZAK, PEGGY TSO, J. RODERICK DAVEY, and NIZAR N. MAHOMED ABSTRACT. Objective. We asked if patients with metabolic syndrome undergoing total knee replacement (TKR) have an increased risk for symptomatic deep vein thrombosis (DVT) at 3 months followup. Methods. We reviewed 1460 patients from our joint registry undergoing primary, unilateral TKR between 1998-2006. Demographic variables of age, sex, comorbidity, and education were retrieved. Metabolic syndrome was defined as body mass index above 30 kg/m 2 , diabetes, hypertension, and hypercholesterolemia. Logistic regression was used to examine the relationship of metabolic syn- drome on the incidence of DVT. Results. The overall incidence of symptomatic DVT was 4.4% (65/1460). Patients with metabolic syndrome had an increased incidence of DVT compared to those without metabolic syndrome (15.5% vs 3.4%). Adjusted analysis showed that the risk of symptomatic DVT in patients with meta- bolic syndrome was 3.2 times [odds ratio 3.2, 95% CI (1.0,15.4), p = 0.04] the risk in those without metabolic syndrome. Conclusion. Hospital protocols developed for prophylactic anticoagulation following TKR should give special consideration to patients with metabolic syndrome. (First Release August 15 2009; J Rheumatol 2009;36:2298–301; doi:10.3899/jrheum.090282) Key Indexing Terms: METABOLIC SYNDROME DEEP VEIN THROMBOSIS KNEE ARTHROPLASTY From the Division of Orthopedic Surgery, University of Toronto, Toronto; and Population Health Research Institute, McMaster University, Hamilton, Ontario, Canada. R. Gandhi, MD, MS, FRCSC, Assistant Professor, Division of Orthopedic Surgery, University of Toronto; F. Razak, BASc, MSc, Population Health Research Institute, McMaster University, and Division of Orthopedic Surgery, University of Toronto; P. Tso, BHSc; J.R. Davey, MD, FRCSC, Assistant Professor; N.N. Mahomed, MD, ScD, Assistant Professor, Division of Orthopedic Surgery, University of Toronto. Address correspondence to Dr. R. Gandhi, Toronto Western Hospital, East Wing 1-439, 399 Bathurst St, Toronto ON, Canada. E-mail: rajiv.gandhi@uhn.on.ca Accepted for publication May 1, 2009. The incidence of asymptomatic deep vein thrombosis (DVT) following total knee replacement (TKR) ranges from 40 to 84% without prophylaxis 1 . Prophylaxis with low molecular weight heparin (LMWH) decreases that incidence to about 30% in TKR 2-5 . The incidence of symptomatic DVT following TKR is 2.1% with the use of thrombopro- phylaxis 6 . The incidence of fatal pulmonary embolus (PE) is estimated at 0.5-2.0% 7-12 . Prophylactic measures for DVT following joint arthro- plasty include early ambulation, mechanical compression devices, and pharmacologic agents. Clinical risk factors for DVT include increasing age, immobility, a history of DVT/PE, obesity, congestive heart failure, and hypercoagu- lable states such as protein C and protein S deficiency 13,14 . Metabolic syndrome is defined as central adiposity, ele- vated fasting glucose level, hypertension, and dyslipidemia defined as high triglyceride and low high-density lipopro- tein (HDL) cholesterol 15,16 . Patients having at least 3 of these 5 criteria are at 1.5 to 2-fold increased risk of cardio- vascular disease 16 . The underlying etiology of the metabol- ic syndrome recognizes adipose tissue as an active endocrine organ that expresses tumor necrosis factor (TNF)-α, interleukin (IL)-6, and C-reactive protein (CRP), which together induce a proinflammatory state that mediates insulin resistance 17-20 . Moreover, metabolic syndrome is associated with a systemic prothrombotic state 15,21-23 . A few studies have shown that there is an increased incidence of DVT in those with metabolic syndrome; however, this has not been explored as a risk factor following TKR 24-26 . We asked if the incidence of symptomatic DVT follow- ing TKR is greater in those patients with metabolic syn- drome compared to those without metabolic syndrome at 3 months followup. MATERIALS AND METHODS As part of our prospective total joint replacement registry, patients are recruited from a single Canadian academic institution, the Toronto Western Hospital, while on a waiting list for primary knee replacement surgery. All patients give informed consent to participate in the registry. Our inclusion criteria for this study were: age years 18 and above and diagnosis of pri- mary or secondary osteoarthritis. The study protocol was approved by the Human Subject Review Committee. All surgeries were performed by 1 of 3 fellowship trained arthroplasty surgeons between 1998-2006. Surgical technique was similar among the 3 www.jrheum.org Downloaded on February 17, 2022 from