Abstract
PURPOSE: This study aimed to evaluate the individual and joint associations of malnutrition and obesity on predicting the severity and prognosis of acute pancreatitis (AP). PATIENTS AND METHODS: A retrospective analysis of 240 AP patients was conducted. Malnutrition was diagnosed using Global Leadership Initiative on Malnutrition (GLIM) criteria. Obesity was defined using body mass index (BMI) and different ratios of psoas muscle area (PMA) to BMI, of which PMA/BMI was used to define sarcopenic obesity. Patients were categorized into four groups: well-nourished non-obese (WN), malnourished non-obese (MN), well-nourished obese (WO), and malnourished obese (MO). Logistic regression, and trend analyses were employed to assess associations with different AP outcomes. RESULTS: The MO group exhibited the highest C-reactive protein levels, lowest albumin/hemoglobin, and worst clinical outcomes. Sarcopenic obesity (MO and WO) significantly increased risks of moderately severe/severe AP (OR ≥2.74), composite outcomes (OR ≥2.69) and AP severity (OR ≥3.27), with the MO group having a risk 5-7 times higher than the WN group. As the PMA/BMI quartiles increase, the risk of moderately severe AP (MSAP)+ severe AP (SAP), composite outcomes and the AP severity significantly increased (all p for trend<0.003), and the group with a median PMA/BMI above (sarcopenic obesity) was significantly correlated with MSAP+SAP (OR ≥3.41), composite outcomes (OR ≥3.26), and the severity of AP (OR ≥3.66). Malnutrition alone did not independently elevate risks. However, no such association was observed in BMI based grouping. CONCLUSION: Sarcopenic obesity, quantified by PMA/BMI, is a superior predictor of AP severity compared to BMI. The coexistence of malnutrition and sarcopenic obesity synergistically exacerbates inflammation and poor outcomes, emphasizing the need for body composition-guided nutritional interventions.