TY - JOUR
T1 - Percent Body Fat and Prediction of Surgical Site Infection
AU - Waisbren, Emily
AU - Rosen, Heather
AU - Bader, Angela M.
AU - Lipsitz, Stuart R.
AU - Rogers, Selwyn O.
AU - Eriksson, Elof
PY - 2010/4
Y1 - 2010/4
N2 - Background: Obesity is a risk factor for surgical site infection (SSI) after elective surgery. Body mass index (BMI) is commonly used to define obesity (BMI ≥30 kg/m2), but percent body fat (%BF) (obesity is >25%BF [men]; >31%BF [women]) might better predict SSI risk because BMI might not reflect body composition. Study Design: This prospective study included 591 elective surgical patients 18 to 64 years of age from September 2008 through February 2009. Height and weight were measured for BMI. %BF was calculated by bioelectrical impedance analysis. Preoperative, operative, and 30-day postoperative data were captured through interviews and chart review. Our primary, predetermined outcomes measurement was SSI as defined by the Center for Disease Control and Prevention. Results: Mean %BF and BMI were 34±10 and 29±8, respectively. Four-hundred and nine (69%) patients were obese by %BF; 225 (38%) were obese by BMI. SSI developed in 71 (12%) patients. With BMI defining obesity, SSI incidence was 12.3% in nonobese and 11.6% in obese patients (p = 0.8); Using %BF, SSI occurred in 5.0% of nonobese and 15.2% of obese patients (p < 0.001). In univariate analyses, significant predictors of SSI were %BF (p = 0.005), obesity by %BF (p < 0.001), smoking (p = 0.002), National Nosocomial Infections Surveillance score (p < 0.001), postoperative hyperglycemia (p = 0.03), and anemia (p = 0.02). In multivariable analysis, obese patients by %BF had a 5-fold higher risk for SSI than nonobese patients (odds ratio = 5.3; 95% CI, 1.2-23.1; p = 0.03). Linear regression was used to show that there is a positive, nonlinear relationship between %BF and BMI. Conclusions: Obesity, defined by %BF, is associated with a 5-fold increased SSI risk. This risk increases as %BF increases. %BF is a more sensitive and precise measurement of SSI risk than BMI. Additional studies are required to better understand this relationship.
AB - Background: Obesity is a risk factor for surgical site infection (SSI) after elective surgery. Body mass index (BMI) is commonly used to define obesity (BMI ≥30 kg/m2), but percent body fat (%BF) (obesity is >25%BF [men]; >31%BF [women]) might better predict SSI risk because BMI might not reflect body composition. Study Design: This prospective study included 591 elective surgical patients 18 to 64 years of age from September 2008 through February 2009. Height and weight were measured for BMI. %BF was calculated by bioelectrical impedance analysis. Preoperative, operative, and 30-day postoperative data were captured through interviews and chart review. Our primary, predetermined outcomes measurement was SSI as defined by the Center for Disease Control and Prevention. Results: Mean %BF and BMI were 34±10 and 29±8, respectively. Four-hundred and nine (69%) patients were obese by %BF; 225 (38%) were obese by BMI. SSI developed in 71 (12%) patients. With BMI defining obesity, SSI incidence was 12.3% in nonobese and 11.6% in obese patients (p = 0.8); Using %BF, SSI occurred in 5.0% of nonobese and 15.2% of obese patients (p < 0.001). In univariate analyses, significant predictors of SSI were %BF (p = 0.005), obesity by %BF (p < 0.001), smoking (p = 0.002), National Nosocomial Infections Surveillance score (p < 0.001), postoperative hyperglycemia (p = 0.03), and anemia (p = 0.02). In multivariable analysis, obese patients by %BF had a 5-fold higher risk for SSI than nonobese patients (odds ratio = 5.3; 95% CI, 1.2-23.1; p = 0.03). Linear regression was used to show that there is a positive, nonlinear relationship between %BF and BMI. Conclusions: Obesity, defined by %BF, is associated with a 5-fold increased SSI risk. This risk increases as %BF increases. %BF is a more sensitive and precise measurement of SSI risk than BMI. Additional studies are required to better understand this relationship.
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U2 - 10.1016/j.jamcollsurg.2010.01.004
DO - 10.1016/j.jamcollsurg.2010.01.004
M3 - Article
C2 - 20347729
AN - SCOPUS:77949892696
SN - 1072-7515
VL - 210
SP - 381
EP - 389
JO - Journal of the American College of Surgeons
JF - Journal of the American College of Surgeons
IS - 4
ER -