professor Pusan National University Yangsan Hospital, United States
Introduction: It remains uncertain whether muscle mass or fat mass plays a crucial role in the obesity paradox of sepsis.
Methods: Seven hundred five patients with sepsis who had undergone abdominal CT from September 2019 to July 2022 were divided into two groups based on the psoas muscle index (PMI): high PMI (n=411) and low PMI (n=294). We evaluated the relationship between PMI and one-year survival in patients with sepsis. Furthermore, the patients were classified into four groups based on their body fat percentage (BFP), and their one-year survival rates were compared.
Results: Overall, the hospital survival rate was 69.1%, and of those, 46.6% were discharged to their homes. Within one year, 24.6% of the patients were readmitted to the hospital for various reasons. 5.3% were readmitted due to sepsis. One-year survival was higher (39.4% vs 23.8%, p< 0.001), and the readmission rate was lower (14.6% vs 20.4%, p=0.043) in the high-PMI group compared to the low-PMI group. In multivariate Cox analysis, age (hazard ratio (HR) 1.02, p < 0.001), male (HR 0.72, p =0.002), Sequential Organ Failure Assessment (HR 1.15, p < 0.001), PMI (HR 0.80, p< 0.001) and solid malignancy (HR 1.76, p< 0.001) were associated with 1-year mortality. When classified into four groups according to PMI and BFP, 46.1% were non-sarcopenic obese, 25% were sarcopenic non-obese, 16.7% were sarcopenic obese, and 12.2% were non-sarcopenic non-obese. One-year survival was highest in non-sarcopenic non-obese (40.7%), followed by non-sarcopenic obese (39.1%), sarcopenic non-obese (25.6%), and sarcopenic obese (21.2%) (p < 0.001). Survival was lower in sarcopenic obese (χ2=8.914, p=0.003) and sarcopenic non-obese (χ2= 5.339, p=0.021) than non-sarcopenic non-obese on the Kaplan-Meier curve.
Conclusions: Low PMI was associated with reduced 1-year survival, but BFP was not. The sarcopenic obese had the poorest prognosis.
