Low preoperative skeletal muscle index increases the risk of mortality among resectable pancreatic cancer patients: A retrospective study

Table 1 Patient and tumor characteristics comparing low and high skeletal muscle index or radiodensity

Characteristics	Total (n = 115)	Low SMI (n = 38)	High SMI (n = 77)	P value	Low SMD (n = 26)	High SMD (n = 89)	P value
Age	65.1 (9.0)	68.8 (9.3)	63.3 (8.4)	0.002b	70.8 (7.0)	63.5 (8.9)	< 0.001c
Male sex	71 (61.7)	29 (76.3)	42 (54.5)	0.024a	13 (50.0)	58 (65.2)	0.162
BMI in kg/m2	22.7 (3.3)	20.9 (3.1)	23.6 (3.0)	< 0.001c	24.0 (4.0)	22.3 (2.9)	0.016a
< 20.0	21(18.3)	14 (36.8)	7 (9.1)		5 (19.2)	16 (18.0)
20.0-24.9	69 (60.0)	20 (52.6)	49 (63.6)		10 (38.5)	59 (66.3)
≥ 25.0	25 (21.7)	4 (10.5)	21 (27.3)	0.001b	11 (42.3)	14 (15.7)	0.01a
Albumin in g/dL	42.5 (5.6)	40.6 (4.1)	43.5 (6.1)	0.01a	41.7 (7.7)	42.8 (4.9)	0.393
Tumor location
Head	67 (58.3)	29 (76.3)	38 (49.4)		18 (69.2)	49 (55.1)
Body + tail	48 (41.7)	9 (23.7)	39 (50.6)	0.006b	8 (30.8)	40 (44.9)	0.197
Tumor size in cm	3.6 (1.4)	3.7 (1.7)	3.3 (1.2)	0.942	3.3 (1.3)	3.6 (1.4)	0.602
Differentiation
Well	5 (4.3)	1 (2.7)	4 (5.3)		3 (12.0)	4 (4.6)
Moderate	100 (87.0)	31 (83.8)	69 (92.0)		19 (76.0)	81 (93.1)
Poor	7 (6.1)	5 (13.5)	2 (2.7)	0.04a	3 (12.0)	2 (2.3)	0.774
Nodal metastases	64 (55.7)	20 (52.6)	44 (57.1)	0.647	12 (46.2)	52 (58.4)	0.268
Perineural invasion1	81 (86.2)	27 (87.1)	54 (85.7)	0.855	25 (100)	56 (81.2)	0.046a
R1 resection	13 (11.3)	3 (7.9)	10 (13.2)	0.602	3 (11.5)	10 (11.4)	1.000
Adjuvant therapy	84 (73.0)	24 (63.2)	60 (77.9)	0.093	18 (69.2)	66 (74.2)	0.618
TNM stage
I	43 (37.4)	14 (36.8)	29 (37.7)		14 (53.8)	29 (32.6)
II	57 (49.6)	19 (50.0)	38 (49.4)		10 (38.5)	47 (52.8)
III	15 (13.0)	5 (13.1)	10 (13.0)	0.996	2 (7.6)	13 (14.6)	0.135
CA19-9 > 200 KU/L	71 (61.7)	24 (66.7)	47 (63.5)	0.746	21 (84.0)	50 (58.8)	0.021a
SMA in cm2	123.0 (30.6)	108.4 (19.9)	130.2 (32.4)	< 0.001c	113.2 (28.4)	125.9 (30.7)	0.056
SMD in HU	39.4 (8.6)	38.5 (10.0)	39.8 (7.8)	0.462	28.5 (5.1)	42.6 (6.5)	< 0.001c
SMI in cm2/m2	44.6 (9.8)	38.1 (5.3)	47.7 (10.0)	< 0.001c	41.1 (9.0)	45.6 (9.9)	0.033a
VAT in cm2	113.4 (66.5)	89 (50.2)	125.4 (70.5)	< 0.001c	151.0 (60.2)	102.4 (64.5)	0.001b
SAT in cm2	121.4 (64.6)	100.5 (45.4)	131.7 (70.2)	0.014a	160.0 (89.3)	110.1 (50.7)	< 0.001c
NLR > 2.6	44 (38.3)	16 (42.1)	28 (36.4)	0.551	13 (50.0)	31 (34.8)	0.162
PLR > 108	77 (67.0)	27 (71.1)	50 (64.9)	0.512	21 (80.8)	56 (62.9)	0.089
SIII > 400	68 (59.1)	24 (63.2)	44 (57.1)	0.537	17 (65.4)	51 (57.3)	0.461

¹Data were available for 94 patients. Statistics are presented as the means (standard deviations) for age, body mass index, albumin, tumor size, and body composition parameters and n (%) for the other parameters.

^aP < 0.05.

^bP < 0.01.

^cP < 0.001.

SMA: Skeletal muscle area; SMD: Skeletal muscle radiodensity; HU: Hounsfield units; SMI: Skeletal muscle index; VAT: Visceral adipose tissue; SAT: Subcutaneous adipose tissue; NLR: Neutrophil-to-lymphocyte ratio; PLR: Platelet-to-lymphocyte ratio; SIII: Systemic immune-inflammation index; BMI: Body mass index; CA19-9: Carbohydrate antigen 19-9.