Psoas muscle volume as a diagnostic indicator for sarcopenia: criteria development and comparison with traditional diagnostic approaches

BACKGROUND: Sarcopenia significantly impacts quality of life and increases the risk for various health issues. This study aims to establish a new, effective diagnostic criterion for sarcopenia based on psoas muscle volume (PV) using computed tomography (CT). AIMS: We analyzed the population distribution of psoas muscle volume (PV), assessed its correlation with ASM indices, and developed CT-based diagnostic criteria for sarcopenia. METHODS: A total of 3,999 adults (2,085 men, 1,914 women; aged 22–89) who underwent abdominal CT and bioimpedance analysis (BIA) were included. Psoas muscle volume was automatically segmented using a deep-learning algorithm. Correlations with ASM indices were evaluated, and diagnostic criteria were established using (1) linear regression, (2) ROC analysis, and (3) T-score analysis referencing young, non-sarcopenic adults. RESULTS: The distribution of PV indices peaked in the 30s and declined with age, more sharply in men. PV showed strong correlations with ASM indices, particularly the PV/BMI index, which demonstrated the highest diagnostic accuracy. T-score adjustment to -2.0 better matched known prevalence rates. DISCUSSION: This study proposes CT-based diagnostic criteria for sarcopenia using psoas muscle volume, demonstrating strong correlation with established indices. These findings support opportunistic screening via CT, offering a practical, population-wide tool for early sarcopenia detection. CONCLUSIONS: This study uncovers the distribution of PV across age groups, noting a significant decline from the 30s to the 70s. This advancement in the objective diagnosis of sarcopenia via imaging positions abdomen CT scans as a potential diagnostic screening tool for low muscle mass compatible with sarcopenia.