The Impact of Preoperative Nutritional Intervention on Muscle Mass Preserve in Older Adult Undergoing Elective Surgery: A Prospective Cohort Study (SiPAP Trail) Study

Sarcopenia-the progressive loss of muscle mass and strength-is a major clinical issue, especially in surgical patients with malignancy. It's strongly linked to poor postoperative outcomes like increased complications, longer hospital stays, and higher mortality. Surgical stress (trauma, fasting, immobilization) significantly worsens this muscle catabolism. Consequently, early identification and targeted preoperative intervention are essential. Preoperative nutrition, part of a prehabilitation program, is a key strategy known to attenuate muscle loss and improve recovery. The Skeletal Muscle Index (SMI) is an objective metric used for risk stratification. The Siriraj Integrated Preoperative and Prehabilitation Center (SiPAP) uses a multidisciplinary model with nutritional counseling, but lacks routine sarcopenia screening or objective SMI measurement. Therefore, the impact of their specific nutritional interventions on preserving muscle mass remains unevaluated. Hypothesis: The structured, individualized preoperative nutritional intervention delivered by SiPAP to intraabdominal oncology patients will result in a net preservation or positive change in the Skeletal Muscle Index (SMI) over the preoperative period.