Impact of gastrectomy on body composition within 1 month in patients with gastric cancer

Purpose The present study examined the changes in and risk factors for body composition (BC) during the first postoperative month when dynamic biological reactions occur. Methods We retrospectively assessed 202 patients who underwent gastrectomy. The BC was assessed using a bioelectrical impedance analysis and evaluated within 1 month preoperatively, 1 week postoperatively, and 1 month postoperatively. Multiple regression analyses were performed to identify predictive factors for BC change. Results The mean reduction rate in BC at 1 month postoperatively was - 6.0, - 10.5, - 5.6, - 1.1, - 10.1, and + 1.2% for body weight, body fat, skeletal muscle, bone mineral, extracellular water/total body water, and the whole-body phase angle, respectively. A multiple regression analysis revealed that independent risk factors for weight loss were complications, operative time, and type of gastrectomy (P = 0.004, 0.011, 0.015, respectively), and those for skeletal muscle loss were complications and gastrectomy type (P = 0.002, 0.010, respectively). A segmental lean mass analysis revealed that the lower limbs were markedly reduced at 1 week postoperatively (- 8.0%), and these independent risk factors were the female sex and Stage II/III disease (P = 0.008, 0.036, respectively). Conclusion Detailed analyses of BC might help elucidate the mechanisms underlying postoperative physical changes, which might be useful for perioperative management.