Table 1.

Baseline Characteristics

	Normal weight	Underweight	Overweight	Obese	p value
	BMI 18.5–25(kg/m2)	BMI < 18.5(kg/m2)	BMI 25–30(kg/m2)	BMI > 30(kg/m2)
	(N = 1815)	(N = 100)	(N = 1635)	(N = 743)
Demographics
Age, years (mean ± SD)	53.7 (±18.9)	51.6 (±21.6)	57.0 (±15.5)a	55.5 (±14.9)a	<0.001
BMI (mean ± SD)	22.6 (±1.7)	17.3 (±1.1)	27.2 (±1.4)	33.5 (±3.4)	<0.001
Male sex (%)	893 (49.2 %)	39 (39.0 %)a	970 (59.3 %)a	315 (42.5 %)a	<0.001
ASA classification (%)		a	a	a	<0.001
I	727 (40.1 %)	31 (31.3 %)	535 (32.8 %)	135 (18.2 %)
II	553 (30.5 %)	20 (20.2 %)	636 (39.0 %)	362 (48.8 %)
III	460 (25.4 %)	39 (39.4 %)	412 (25.3 %)	223 (30.1 %)
IV	72 (4.0 %)	8 (8.1 %)	47 (2.9 %)	21 (2.8 %)
V	1 (<1 %)	1 (<1 %)	0 (0.0 %)	1 (<1 %)
Medical history (%)
Diabetes mellitus	86 (4.7 %)	6 (6.1 %)	162 (9.9 %)a	134 (18.1 %)a	<0.001
Hypertension	257 (14.2 %)	14 (14.1 %)	360 (22.1 %)a	225 (30.3 %)a	<0.001
Cerebrovascular disease	123 (6.8 %)	8 (8.1 %)	118 (7.2 %)	54 (7.3 %)	0.919
Malignant disease	451 (24.9 %)	25 (25.3 %)	362 (22.2 %)a	172 (23.2 %)	0.308
Pathological cardiac history	302 (16.7 %)	18 (18.2 %)	316 (19.4 %)a	158 (21.3 %)a	0.033
Pathological pulmonary history	261 (14.4 %)	15 (15.2 %)	205 (12.6 %)	138 (18.6 %)a	0.002
Current smokingb	490 (35.4 %)	39 (48.8 %)a	374 (30.4 %)a	163 (26.9 %)a	<0.001
Surgery risk (%)		a		a	<0.001
Low	1078 (59.4 %)	33 (33.0 %)	969 (59.3 %)	365 (49.1 %)
Intermediate	643 (34.4 %)	52 (52.0 %)	577 (35.3 %)	350 (47.1 %)
High	94 (5.2 %)	15 (15.0 %)	89 (5.4 %)	28 (3.8 %)
Type of anesthesia (%)
General	1499 (82.8 %)	93 (93.9 %)a	1376 (84.3 %)	684 (92.2 %)a	<0.001
Surgical setting (%)
Outpatient surgery	690 (38.0 %)	22 (22.0 %)a	607 (37.1 %)	216 (29.1 %)a	<0.001

^aSignificantly different (p < .05) compared to normal weight

^bData was available in 76.9 % of patients