Effect of total gastrectomy on weight and body composition: A retrospective study

Patients undergoing total gastrectomy (TG) for gastric cancer experience significant weight loss and are at risk for nutritional deficiencies. This study aimed to assess body composition changes following TG, focusing on contribution of skeletal muscle mass loss versus adipose loss.

This retrospective analysis examines patients who underwent TG at a major cancer center (2014-2021). Longitudinal analysis with regression identified factors associated with rate of body mass index (BMI) change. Cross-sectional CT scan imaging quantified body mass loss, including skeletal muscle area (SMA), skeletal muscle index (SMI), subcutaneous fat area (SFA), and visceral fat area (VFA).

Fifty-two TG patients were identified (median age 63 y; 54% male). Higher preoperative BMI predicted greater postoperative weight loss, with BMI > 30 losing more than BMI < 30 (P < 0.001). Weight loss was non-linear, peaking at 6 months (-17%), stabilizing by 12 months, then gradually increasing (P = 0.039). SMA and SMI decreased by 11% at 6 months for both, respectively, with gradual recovery after 12 months. SFA and VFA decreased significantly over 3 years, with peak fat loss evident at 12 months post-surgery, SFA decreased 64% from baseline and VFA decreased 95% from baseline, with minimal recovery thereafter. Skeletal muscle loss peaked 12 months post-TG, including 66% of males and 77% of females, with slight decreases in low skeletal muscle rates at 24 months.

Weight loss post-TG follows a non-linear pattern, with peak loss at 6 months and stabilization at 12 months. Most weight loss is due to loss of visceral and subcutaneous adipose with substantially less muscle loss. Nevertheless, ongoing monitoring for sarcopenia is warranted in both sexes post-TG.