Studies: High blood sugar, obesity increase risk for surgical site infection

In two studies from the Journal of Bone and Joint Surgery, separate teams of researchers found links between surgical site infection and both hyperglycemia and obesity.

For one study, researchers reviewed data on 790 patients 18 years and older who sustained isolated orthopedic injuries requiring acute operative intervention. Patients already diagnosed with diabetes or in the intensive care unit were not included in the study.

The authors reported 268 open fractures among this cohort, with 21 surgical site infections (SSIs) at the 30-day follow-up. Age, race, comorbidities, injury severity and blood transfusion were not associated with SSI at this follow-up. The authors noted, however, that SSIs developed in 13 of the 294 patients (4.4%) presenting with more than one glucose value greater than or equal to 200 mg/dL and 8 of the 496 patients (1.6%) without elevated glucose values.

“Hyperglycemia was an independent risk factor for 30-day [SSI] in orthopedic trauma patients without a history of diabetes,” the authors of the first study wrote.

In the second study, researchers analyzed 7,181 hip and knee replacements, finding 52 postoperative joint infections occurred within the first year — and the infection rate increased from 0.37% in patients with a normal body mass index (BMI) to 4.66% in morbidly obese patients. Diabetes, the authors reported, more than doubled the risk of postoperative joint infection independent of obesity. The highest infection rate was found among patients who were both morbidly obese and diabetic.

Patients with a diagnosis of diabetes at the time of surgery trended toward a higher infection rate in association with a preoperative glucose level of more than 124 mg/dL.

“Diabetes and morbid obesity increased the risk of periprosthetic joint infection following primary hip and knee replacement,” the authors of the second study wrote. “The benefits of joint replacement should be carefully weighed against the incidence of postoperative infection, especially in morbidly obese patients.”

Reference:

Richards JE, Kauffmann RM, Zuckerman SL, et al. Relationship of hyperglycemia and surgical-site infection in orthopaedic surgery. J Bone Joint Surg Am. 2012. doi:10.2106/JBJS.K.00193

Jamsen E, Nevalainen P, Eskelinen A, et al. Obesity, diabetes and preoperative hyperglycemia as predictors of periprosthetic joint infection: A single-center analysis of 7,181 primary hip and knee replacements for osteoarthritis. J Bone Joint Surg Am. 2012. doi: 10.2106/JBJS.J.01935