Dynamic analysis of texture and metabolic feature changes in the rectus femoris in patients with sepsis-induced myopathy during the acute phase

Background Sepsis-induced myopathy (SIM) is a common complication of sepsis that significantly affects clinical outcomes. This study employed bedside ultrasound and the Gray Level Co-occurrence Matrix (GLCM) method to quantitatively analyze changes in the texture features of the rectus femoris during the first week of intensive care unit (ICU) admission in patients with sepsis. Additionally, ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was used to assess metabolic characteristics in SIM patients during the acute phase, providing a foundation for further mechanistic studies and clinical applications. Methods A prospective cohort study was conducted in ICU patients with sepsis. Bedside ultrasound was used to monitor changes in rectus femoris muscle thickness (RF-MLT) and cross-sectional area (RF-CSA) on ICU Days 1, 4, and 7. SIM was diagnosed when (RF-CSA Day 1) - (RF-CSA Day 7) yielded a negative value. GLCM analysis was performed to quantify texture features and their correlation with clinical metabolic markers. UHPLC-MS/MS was employed to evaluate metabolic features during the acute phase of SIM. Results Sixty patients with sepsis were enrolled, with 16 diagnosed with SIM and an ICU stay of at least 7 days. The standard deviation and variance on ICU Day 4 were higher than on Day 1, and the standard deviation on Day 7 exceeded that of Day 1. RF-CSA decreased by Day 7 compared to Day 1. In the SIM group, the standard deviation on Day 4 and the variance on Day 7 were significantly higher than those in the non-SIM (NSIM) group (P < 0.05). Correlation analysis showed that on ICU Day 1, RF-CSA was positively correlated with C-peptide, HDL, and transferrin. On Day 4, standard deviation was negatively correlated with insulin, and on Day 7, it was positively correlated with random blood glucose. RF-CSA on Day 7 showed a positive correlation with total cholesterol (TC), transferrin, and ceruloplasmin, and a negative correlation with UCR.Metabolic characteristics analysis showed that on ICU Days 1 and 7, fatty acid (FA) metabolism was predominantly affected in SIM patients. The relative abundance of 29 metabolites decreased progressively from the Control group to SIM Day 1 and SIM Day 7 groups. The most significantly altered metabolites were docosahexaenoic acid (DHA) and arachidonic acid (AA). Conclusions GLCM detected muscle damage earlier than ultrasound morphological assessment in patients with sepsis and was associated with clinical markers of lipid, glucose, and protein metabolism. During the acute phase of SIM, the FA metabolic pathway was primarily affected, with DHA and AA being the most significantly altered metabolites.