Chronological changes in total body composition and the role of nutritional status in healthy donors post-hepatectomy: an observational cohort study

Background: Sarcopenia and adiposity are important prognostic factors in hepatectomy patients, but physiological changes in healthy donors post-hepatectomy remain unclear. This study evaluates chronological changes in total body composition (TBC) and the role of nutritional status in liver donors. Methods: This prospective cohort study included 100 healthy donors who underwent partial hepatectomy. TBC parameters – including abdominal, psoas, paraspinal muscles, subcutaneous adipose tissue (SAT), and visceral adipose tissue (VAT) – were measured using non-contrast CT at baseline, 3 months, 6 months, and 12 months. Nutritional status was assessed using the prognostic nutritional index (PNI). Generalized estimating equations and linear regression models were used to assess trends and associations. Results: In the TBC analyses, the abdominal muscle index significantly declined (−4.15%, P < 0.001) at 3 months but returned to baseline at 6 months. Muscle density significantly decreased at both 3 months (−4.91%, P < 0.001) and 12 months (−5.14%, P = 0.003). At 12 months, SAT density showed a significant reduction (−16.96%, P = 0.017), whereas VAT density increased by 19.0% ( P = 0.014). Moreover, PNI dropped significantly at 3 months (−5.07%, P < 0.001), with partial recovery by 6 months. In addition, the change in PNI was significantly associated with changes in abdominal, psoas, and paraspinal muscle indices at 6 months. Conclusion: This study provides a reference for post-hepatectomy TBC changes in healthy donors, showing transient muscle loss, persistent SAT reduction, and VAT gain. Nutritional status was positively associated with muscle regeneration, emphasizing the role of nutrition in supporting recovery.