Metabolic syndrome increases risk for pulmonary embolism after hip and knee arthroplasty

Abstract

Aim: To investigate whether patients with metabolic syndrome (MetS) undergoing total hip or knee replacement have an increased risk for pulmonary embolism (PE).

Methods: We studied patients undergoing total hip or total knee replacement from January 2001 to April 2006. The diagnosis of PE was based on a positive finding with a chest CT or a lung scan. Components of MetS were defined as 1) BMI≥30 kg/m(2) , 2) non-fasting preadmission glucose ≥11.1 mmol/L or diagnosis of diabetes, 3) hypertension, and 4) dyslipidemia. MetS was diagnosed if at least three of these components were present.

Results: Of 7282 patients, 107 (1.47%) were diagnosed with PE. The incidence of PE in patients with 0, 1, 2, 3, and 4 MetS components was respectively 0.85% (16/1888; 95% confidence interval [CI] 0.5%-1.4%), 1.24% (31/2500; 95% CI 0.9%-1.8%), 1.76% (34/1936; 95% CI 1.2%-2.5%), 2.64% (21/796; 95% CI 1.7%-4.1%), and 3.09% (5/162; 95% CI 1.1%-7.4%). The independent risk factors for PE were age ≥70, knee as opposite to hip replacement, bilateral knee surgery, congestive heart failure, and MetS or the number of MetS components. The odds of PE independently increased 1.6 times (95% CI 1.01-2.56; P=0.043) for patients with MetS and 1.23 times (95% CI 1.02-1.48; P=0.028) per each additional MetS component.

Conclusion: Patients with MetS are at increased risk for PE after total joint arthroplasty. The increasing number of MetS components significantly increased the incidence of PE.

Figure 1

Incidence of pulmonary embolism (PE) by increasing number of metabolic syndrome (MetS) components. *The incidence of PE significantly increased with the number of MetS components, P < 0.001 (univariate Mantel-Haenszel test). Presented are PE incidence rates and 95% confidence intervals (CI). Each additional risk factor increased the odds for PE by 1.23 (95% CI 1.02-1.48), P = 0.028 (multivariate logistic regression).