Sarcopenic obesity is associated with adverse clinical outcome after cardiac surgery

Both undernutrition - low fat free mass (FFM) - and obesity - high fat mass (FM) - have been associated with adverse outcome in cardiac surgical patients. However, whether there is an additional effect on outcome of these risk factors present at the same time, that is sarcopenic obesity (SO), is unknown. Furthermore, the association between SO and muscle function is unidentified.

In 325 cardiac surgical patients, we prospectively analysed the association between preoperative FFM and FM, measured by bioelectrical impedance spectroscopy, and postoperative adverse outcomes, and their correlation with muscle function - handgrip strength (HGS). SO was associated with postoperative infections (28.2% vs. 5.3%, adj. odds ratio (OR): 7.9; 95% confidence interval (CI): 1.2-54.1; p=0.04). Further, a low FFM index (FFMI; kgm(-2)) was associated with postoperative infections (18.5% vs. 4.7%, adj. OR: 6.6; 95% CI: 1.7-25.2; p=0.01) while a high FM index (FMI; kgm(-2)) was not. Both components of SO, FFMI and FMI, correlated with HGS (FFMI: r=0.570; p<0.001, FMI: r=-0.263; p<0.001).

SO is associated with an increased occurrence of adverse outcome after cardiac surgery. Our results suggest an additional risk of a low FFMI and high FMI present at the same time. Furthermore, SO is characterised by less muscle function. We advocate determining body composition in cardiac surgical patients to classify and treat undernourished patients, in particular those who are also obese.