Out of the 1160 patients with septic shock in the registry, 896 (77.2%) who underwent an abdominal CT at ED were included. The rate of 28-day mortality was 16.3% (n = 146) (Fig. 2).
The baseline characteristics of the study population are presented in Table 1. The median age was 67.0 (58.0–75.0) years with male predominance (58.8%). Non-survivors had higher proportions of chronic pulmonary disease (8.9% vs. 4.5%), malignancy (50.7% vs. 40.4%), hematologic disorder (11.6% vs. 5.5%), and liver cirrhosis (21.2% vs. 14.4%) than survivors. Except for unknown foci and the bloodstream, most sites of infection differed significantly between groups. Non-survivors showed more frequent pulmonary (24.0% vs. 14.9%) and intra-abdominal sources (22.6% vs. 14.4%), but less in the urinary tract (9.6% vs. 16.9%), hepato-biliary-pancreas sources (32.2% vs. 41.5%) than survivors. Also, the non-survivor group had significantly higher lactate levels, SOFA scores, and APACHE scores than the survivor group. Based on diagnosing with current cut-off values, low SMI (63.3%) and myosteatosis (81.7%) were common in the study population; however, there were no significant differences between the two groups. Separate demographics and clinical characteristics of each gender are presented in the supplementary tables (Supplementary Table S1, Supplementary Table S2).
Table 1
Baseline characteristics of septic shock according to 28-day mortality
Characteristics | Total (n = 896) | Survivor (n = 750) | Non-survivor (n = 146) | P-value |
Age | 67.0 (58.0–75.0) | 69.0 (60.0–76.0) | 63.5 (53.8–69.0) | 0.11 |
Male | 527 (58.8) | 433 (57.7) | 94 (64.4) | 0.14 |
Past illness | | | | |
HTN | 299 (33.4) | 253 (33.7) | 46 (31.5) | 0.60 |
DM | 230 (25.7) | 195 (26.0) | 35 (24.0) | 0.61 |
CAD | 77 (8.6) | 69 (9.2) | 8 (5.5) | 0.14 |
Chronic pulmonary disease | 47 (5.2) | 34 (4.5) | 13 (8.9) | 0.03 |
Malignancy | 377 (42.1) | 303 (40.4) | 74 (50.7) | 0.02 |
Hematologic disorder | 58 (6.5) | 41 (5.5) | 17 (11.6) | < 0.01 |
CKD | 51 (5.7) | 45 (6.0) | 6 (4.1) | 0.37 |
LC | 139 (15.5) | 108 (14.4) | 31 (21.2) | 0.04 |
Site of infection | | | | |
Unknown | 82 (9.2) | 67 (8.9) | 15 (10.3) | 0.61 |
Lung | 147 (16.4) | 112 (14.9) | 35 (24.0) | < 0.01 |
Urinary tract | 141 (15.7) | 127 (16.9) | 14 (9.6) | 0.03 |
Intra-abdomen | 141 (15.7) | 108 (14.4) | 33 (22.6) | 0.01 |
Hepato-biliary-pancreas | 358 (40.0) | 311 (41.5) | 47 (32.2) | 0.04 |
Blood stream | 66 (7.4) | 51 (6.8) | 15 (10.3) | 0.20 |
Lactate level | 3.6 (1.9–5.8) | 3.2 (1.7–5.4) | 5.4 (2.6–9.2) | < 0.01 |
SOFA score | 7.0 (5.0–10.0) | 7.0 (5.0–9.0) | 10.0 (6.0–13.0) | < 0.01 |
APACHE score | 15.0 (11.0–20.0) | 13.0 (11.0–23.0) | 17.0 (11.0–23.0) | < 0.01 |
Low SMI | 567 (63.3) | 474 (63.2) | 93 (63.7) | 0.91 |
Myosteatosis | 732 (81.7) | 607 (80.9) | 125 (85.6) | 0.19 |
Data are presented as n (%) or median (interquartile range). |
Abbreviations: HTN, hypertension; DM, diabetes mellitus; CAD, coronary artery disease; CKD, chronic kidney disease; LC, liver cirrhosis; SOFA, sequential organ failure assessment; APACHE, acute physiology and chronic health evaluation; SMI, skeletal muscle index. |
The baseline characteristics and body composition of the study population according to the presence of abnormal myosteatosis are summarized in Supplementary Table S3. Patients with abnormal myosteatosis were older (68.0 vs. 61.0 years), had fewer males (57.2% vs. 65.9%), more frequent hypertension (37.6% vs. 14.6%), diabetes mellitus (27.0% vs. 19.5%), coronary artery disease (9.6% vs. 4.3%), urinary tract infection (17.1% vs. 9.8%), higher lactate level (4.0 vs. 2.6 mmol/L), SOFA score (7.0 vs. 6.0), APACHE score (16.0% vs. 13.0), BMI (23.0 vs. 19.3 kg/m2), SFA (119.0 vs. 57.9 cm2), VFA (117.8 vs. 33.9 cm2), intramuscular adipose tissue area (18.3 vs. 6.1 cm2), low-attenuation MA (53.5 vs. 28.0 cm2), total abdominal MA (126.5 vs. 110.6 cm2), myosteatosis area (72.8 vs. 35.0 cm2), and myosteatosis percentage (58.1% vs. 29.2%). Normal-attenuation MA (51.4 vs. 80.4 cm2) was significantly lower in the abnormal myosteatosis patient group.
Figure 3 illustrates the median myosteatosis area and percentage according to age groups for male and female patients. Trends in myosteatosis area and percentage according to age groups showed differed significantly between males and females. The detailed body morphometry in all patients and by sex is presented in Table 2. Compared with females, the body compositions of males tended to differ significantly between the survivor and non-survivor groups. Male non-survivors had smaller SMA (114.4 vs. 120.3 cm2), smaller normal-attenuation MA (60.3 vs. 73.3 cm2), smaller total abdominal MA (128.8 vs. 138.4 cm2), larger low-attenuation MA (53.8 vs. 49.0 cm2), and larger myosteatosis percentage (51.8% vs. 46.1%). However, these differences were not observed in female patients, except low-attenuation MA (54.3 vs. 46.5 cm2) and myosteatosis percentage (69.1% vs. 60.9%).
Table 2
Body composition of the study population
Body composition | Total (n = 896) | Survivors (n = 750) | Non-survivors (n = 146) | P-value |
Total | | | | |
BMI, kg/m2 | 22.2 (19.7–24.6) | 22.3 (19.7–24.6) | 21.9 (19.7–24.9) | 0.64 |
SFA, cm2 | 107.3 (65.7–157.0) | 110.0 (66.6–157.2) | 94.9 (56.6–150.5) | 0.07 |
VFA, cm2 | 101.0 (57.7–158.9) | 102.3 (57.4–160.4) | 90.9 (59.0–147.7) | 0.20 |
SMA, cm2 | 106.2 (90.6–125.6) | 106.1 (89.8–126.7) | 106.7 (93.8–119.6) | 0.76 |
✢SMI, cm2/m2 | 40.6 (36.3–46.0) | 40.6 (36.3–46.4) | 41.0 (36.0–44.6) | 0.67 |
Normal-attenuation MA, cm2 | 56.8 (37.8–78.4) | 57.4 (39.6–79.7) | 52.8 (32.8–69.6) | < 0.01 |
Intramuscular adipose tissue area, cm2 | 16.0 (9.6–23.2) | 16.3 (9.7–23.3) | 14.9 (9.2–22.6) | 0.42 |
Low-attenuation MA, cm2 | 49.2 (36.8–60.9) | 47.6 (36.0–59.5) | 54.1 (42.7–66.4) | < 0.01 |
✢Total abdominal MA, cm2 | 123.5 (109.2–142.1) | 123.2 (109.0–143.3) | 124.9 (109.9–136.2) | 0.59 |
✢✢Myosteatosis area, cm2 | 66.6 (47.5–84.1) | 65.9 (46.6–83.3) | 70.7 (55.2–90.5) | 0.03 |
✢✢✢Myosteatosis percentage, % | 0.53 (0.40–0.67) | 0.53 (0.39–0.66) | 0.57 (0.44–0.71) | < 0.01 |
Male | | | | |
BMI, kg/m2 | 22.0 (19.7–24.4) | 22.1 (19.7–24.4) | 21.6 (20.0–24.4) | 0.63 |
SFA, cm2 | 87.7 (52.6–131.1) | 88.8 (55.8–131.3) | 83.9 (49.6–123.8) | 0.26 |
VFA, cm2 | 110.1 (60.4–170.2) | 113.1 (59.0–171.7) | 97.2 (65.4–158.0) | 0.30 |
SMA, cm2 | 118.9 (105.3–137.2) | 120.3 (106.2–138.3) | 114.4 (101.0–125.9) | < 0.01 |
✢SMI, cm2/m2 | 42.7 (38.5–49.3) | 42.8 (38.6–49.6) | 42.1 (37.4–46.0) | 0.07 |
Normal-attenuation MA, cm2 | 70.2 (52.0–89.3) | 73.3 (54.3–92.2) | 60.3 (45.5–73.0) | < 0.01 |
Intramuscular adipose tissue area, cm2 | 14.9 (8.6–21.1) | 14.9 (8.7–21.1) | 14.0 (7.5–21.7) | 0.57 |
Low-attenuation MA, cm2 | 50.0 (36.6–62.8) | 49.0 (35.3–62.6) | 53.8 (44.8–65.0) | 0.02 |
✢Total abdominal MA, cm2 | 135.2 (120.4–152.6) | 138.4 (121.3–154.6) | 128.8 (115.1–144.7) | < 0.01 |
✢✢Myosteatosis area, cm2 | 65.9 (46.3–84.1) | 65.5 (45.7–83.5) | 67.0 (55.2–86.4) | 0.13 |
✢✢✢Myosteatosis percentage, % | 47.7 (35.1–60.2) | 46.1 (33.7–59.4) | 51.8 (40.5–66.2) | < 0.01 |
Female | | | | |
BMI, kg/m2 | 22.6 (19.7–24.9) | 22.6 (19.7–24.8) | 22.4 (19.6–25.8) | 0.96 |
SFA, cm2 | 137.8 (93.8–181.4) | 138.4 (95.6–181.4) | 124.9 (81.0–186.6) | 0.53 |
VFA, cm2 | 91.1 (53.8–133.0) | 91.7 (55.6–136.4) | 85.4 (33.3–130.1) | 0.27 |
SMA, cm2 | 90.6 (80.0–100.8) | 90.9 (80.3–100.4) | 89.3 (79.1–104.0) | 0.51 |
✢SMI, cm2/m2 | 37.9 (34.1–41.7) | 37.8 (33.9–41.5) | 37.9 (34.1–43.6) | 0.60 |
Normal-attenuation AMA, cm2 | 41.0 (28.2–55.9) | 42.4 (28.6–56.0) | 33.7 (23.5–53.3) | 0.08 |
Intramuscular adipose tissue area, cm2 | 17.9 (12.0–25.7) | 18.0 (11.9–25.5) | 16.8 (12.6–27.0) | 0.71 |
Low-attenuation MA, cm2 | 48.0 (36.9–58.7) | 46.5 (36.6–57.8) | 54.3 (40.6–66.6) | < 0.01 |
✢Total abdominal MA, cm2 | 109.8 (98.8–121.7) | 109.3 (98.7–120.9) | 114.8 (99.1–127.7) | 0.29 |
✢✢Myosteatosis area, cm2 | 67.3 (49.4–84.3) | 66.8 (48.7–83.0) | 75.2 (54.0–95.2) | 0.13 |
✢✢✢Myosteatosis percentage, % | 61.5 (47.8–75.1) | 60.9 (47.3–74.6) | 69.1 (53.1–77.7) | 0.05 |
✢Total abdominal MA was derived by adding the Normal-attenuation MA, Intramuscular adipose tissue area, and Low-attenuation MA. |
✢✢Myosteatosis area was derived by adding the Low-attenuation MA and Intramuscular adipose tissue area. |
✢✢✢Myosteatosis proportion was defined as myostatosis divided by Total abdominal MA. |
Data are presented as median (interquartile range). |
Abbreviations: BMI, body mass index; SFA, subcutaneous fat area; VFA, visceral fat area; SMA, skeletal muscle area; SMI, skeletal muscle area index; MA, muscle area. |
Table 3
Multivariate analysis of septic shock patients for its association with 28-day mortality
Variables | Univariate analysis | Multivariate analysis |
OR | 95% CI | P-value | Adjusted OR | 95% CI | P-value |
Male | | | | | | |
CAD | 0.44 | 0.16–1.26 | 0.13 | 0.44 | 0.16–1.25 | 0.12 |
Hematologic disorder | 1.09 | 0.44–2.73 | 0.85 | | | |
CKD | 0.24 | 0.05–1.20 | 0.08 | 0.22 | 0.04–1.06 | 0.06 |
Chronic liver disease | 1.45 | 0.76–2.78 | 0.26 | | | |
Urinary tract infection | 0.40 | 0.13–1.28 | 0.12 | 0.33 | 0.11–0.99 | 0.05 |
Intra-abdominal infection | 1.39 | 0.69–2.81 | 0.36 | | | |
Hepato-biliary-pancreas infection | 0.52 | 0.28–0.97 | 0.04 | 0.45 | 0.26–0.77 | < 0.01 |
Blood stream infection | 2.46 | 0.77–7.88 | 0.13 | | | |
Lactate | 1.18 | 1.09–1.28 | < 0.01 | 1.19 | 1.10–1.29 | < 0.01 |
SOFA | 1.11 | 1.02–1.21 | 0.02 | 1.13 | 1.05–1.21 | < 0.01 |
APACHE | 1.01 | 0.97–1.05 | 0.68 | | | |
SMI | 0.97 | 0.94–1.00 | 0.07 | 0.97 | 0.94–0.99 | 0.05 |
Myosteatosis percentage | 1.02 | 1.01–1.03 | 0.04 | 1.02 | 1.01–1.03 | 0.04 |
Female | | | | | | |
Hematologic disorder | 0.65 | 0.13–3.34 | 0.61 | | | |
Malignancy | 2.59 | 1.25–5.37 | 0.01 | 2.77 | 1.35–5.67 | < 0.01 |
Lung infection | 2.00 | 0.82–4.88 | 0.13 | | | |
Blood stream infection | 3.32 | 0.87–12.63 | 0.08 | 2.97 | 0.87–10.11 | 0.08 |
Lactate | 1.07 | 0.96–1.19 | 0.22 | | | |
SOFA | 1.15 | 1.01–1.31 | 0.04 | 1.19 | 1.05–1.34 | < 0.01 |
APACHE | 1.08 | 1.01–1.14 | 0.02 | 1.08 | 1.02–1.14 | 0.01 |
Myosteatosis percentage | 1.01 | 0.11–8.98 | 0.99 | | | |
Abbreviations: OR, odds ratio; CI, confidence interval; CAD, coronary artery disease; CKD, chronic kidney disease; SOFA, sequential organ failure assessment; APACHE, acute physiology and chronic health evaluation. |
In the univariate analysis, the following covariates were associated with 28-day mortality: coronary artery disease, hematologic disorder, chronic kidney disease, chronic liver disease, urinary tract infection, intra-abdominal infection, hepato-biliary-pancreas infection, bloodstream infection, initial lactate level, SOFA, APACHE, SMI, and myosteatosis percentage for males; hematologic disorders, malignancy, lung infection, bloodstream infection, initial lactate level, SOFA, APACHE, and myosteatosis percentage for females (Supplementary Table 1 and Supplementary Table 2). Multivariable logistic regression analyses for male patients showed that the lower SMI (adjusted OR 0.97; 95% CI 0.94–0.99; P = 0.05) and higher myosteatosis percentage (adjusted OR 1.02; 95% CI 1.01–1.03; P = 0.04) were independently associated with a lower 28-day mortality. Meanwhile, neither SMI nor myosteatosis percentage was significantly associated with 28-day mortality in females.