Table 2.

Hazard ratios of perioperative BMI and BMI loss

No. at riskNo. of eventsUnadjusted HR (95% CI)Multivariable-adjusted HR (95% CI)a
Overall survival
Preoperative BMI (n = 2,063)
 <18.582211.23 (0.78–1.94)0.82 (0.51–1.30)
 18.5 to <23.07611681 [Reference]
 23.0 to <25.0539760.60 (0.46–0.79)0.62 (0.47–0.81)
 25.0 to <27.5456520.48 (0.35–0.66)0.59 (0.43–0.80)
 ≥27.5225300.59 (0.40–0.87)0.72 (0.48–1.06)
Postoperative BMI (n = 1,845)
 <18.5208551.82 (1.34–2.46)1.71 (1.25–2.35)
 18.5 to <23.01,0811751 [Reference]
 23.0 to <25.0364320.51 (0.35–0.75)0.65 (0.44–0.96)
 25.0 to <27.5145120.49 (0.27–0.88)0.64 (0.35–1.16)
 ≥27.54730.39 (0.12–1.22)0.82 (0.26–2.60)
BMI lossb (n = 1,845)
 ≤4.51,6572261 [Reference]
 >4.5188512.27 (1.68–3.08)1.79 (1.28–2.49)
Cancer-specific survival
Preoperative BMI
 <18.58291.08 (0.54–2.15)0.57 (0.28–1.16)
 18.5 to <23.0761811 [Reference]
 23.0 to <25.0539360.60 (0.40–0.89)0.67 (0.45–1.01)
 25.0 to <27.5456290.56 (0.37–0.86)0.79 (0.51–1.22)
 ≥27.5225150.60 (0.35–1.05)0.86 (0.49–1.51)
Postoperative BMI
 <18.5208301.65 (1.10–2.47)1.47 (0.96–2.25)
 18.5 to <23.01,0811031 [Reference]
 23.0 to <25.0364140.39 (0.22–0.67)0.53 (0.30–0.94)
 25.0 to <27.514560.42 (0.18–0.95)0.90 (0.37–2.20)
 ≥27.54710.22 (0.03–1.56)1.08 (0.15–7.95)
BMI lossb
 ≤4.516571191 [Reference]
 >4.5188352.89 (1.98–4.22)1.99 (1.30–3.04)
  • aCox regression models adjusted for age at diagnosis in years, sex (male [reference] or female), ASAs classification (I [reference], II, or ≥III), smoking status (never [reference], past, or current), T-stage (1 [reference], 2, 3, or 4), N-stage (0 [reference], 1, 2, or 3), venous invasion (no [reference], yes), perineural invasion (no [reference], yes), histology (differentiated [reference], undifferentiated, or mixed), chemotherapy (no [reference], yes), and extent of gastric resection (distal gastrectomy [reference], total gastrectomy, proximal gastrectomy, or pylorus-preserving gastrectomy).

  • bBMI loss was calculated as preoperative BMI minus postoperative BMI.