Psoas cross-sectional area as a predictor of mortality and a diagnostic tool for sarcopenia in hip fracture patients

This study aimed to determine: (1) the association between psoas cross-sectional area (PCA) and mortality in hip fracture patients, and (2) the usefulness of PCA as a diagnostic tool for sarcopenia. A total of 373 female and 121 male hip fracture patients aged 50 years or more who had surgical repair of their hip fracture between 2011 and 2017 were analyzed. PCA was measured at L4-L5 disc level using CT. PCA of gender-specific 20th percentile determined from this study cohort was used as a cutoff value. The effect of decreased PCA on mortality was analyzed. The association between PCA and appendicular lean mass (ALM) or/and grip strength was analyzed. In survival time of both genders, a significant difference was found between patients with the lowest quintile and upper 4 quintiles (p < 0.001 for females, p = 0.040 for males). The lowest quintile of PCA was associated with mortality, with hazard ratio (HR) of 2.33 (95% CI 1.44-3.47, p < 0.001) in females and 2.01 (95% CI 1.01-3.98, p = 0.046) in males. After adjustment of age, American Society of Anesthesiologists classification, body mass index, dementia, and a grip strength, the lowest quintile of PCA was significantly associated with mortality only in females, with HR of 1.76 (95% CI 1.05-2.70, p = 0.017). A moderate association between PCA and ALM was found in both genders (r = 0.358 for females, r = 0.455 for males). In conclusion, measurement of PCA has potential as a prognostic predictor and diagnostic tool for sarcopenia.