Table 1.
Baseline characteristics of participants according to BMI category (N = 15174).
| Characteristic | BMI (kg/m2) | P value | |||
|---|---|---|---|---|---|
| Underweight <18.5 |
Normal ≥18.5, <25 |
Overweight ≥25, <30 |
Obese ≥30 |
||
| Clinical parameters (n) | 378 | 4683 | 5084 | 5029 | |
| BMI (kg/m2) | 17.63 ± 0.58 | 22.46 ± 1.73 | 27.38 ± 1.41 | 35.91 ± 5.60 | <0.001 |
| Age (years) | 87.05 ± 71.09 | 81.42 ± 61.16 | 74.72 ± 47.22 | 66.80 ± 31.95 | <0.001 |
| Gender, n (%) | <0.001 | ||||
| Female | 225 (59.52) | 2000 (42.71) | 1672 (32.89) | 2056 (40.88) | |
| Male | 153 (40.48) | 2683 (57.29) | 3412 (67.11) | 2973 (59.12) | |
| Ethnicity, n (%) | 0.023 | ||||
| White | 260 (68.78) | 3296 (70.38) | 3658 (71.95) | 3622 (72.02) | |
| Black | 46 (12.17) | 414 (8.84) | 405 (7.97) | 452 (8.99) | |
| Other | 72 (19.05) | 973 (20.78) | 1021 (20.08) | 955 (18.99) | |
| SBP (mmHg) | 116 ± 17 | 116 ± 17 | 116 ± 16 | 116 ± 16 | 0.501 |
| DBP (mmHg) | 59 ± 11 | 59 ± 11 | 59 ± 10 | 59 ± 19 | 0.001 |
| MBP (mmHg) | 76 ± 11 | 77 ± 11 | 77 ± 11 | 76 ± 10 | 0.245 |
| Heart rate (beats/minute) | 87 ± 16 | 86 ± 15 | 86 ± 15 | 87 ± 16 | 0.006 |
| Respiratory rate (beats/minute) | 19 ± 4 | 19 ± 4 | 18 ± 4 | 19 ± 4 | <0.001 |
| Temperature (°C) | 36.7 ± 0.6 | 36.8 ± 0.7 | 36.8 ± 0.7 | 36.9 ± 0.7 | <0.001 |
| SPO2 | 98 ± 2.7 | 98 ± 2.3 | 97 ± 2.2 | 97 ± 2.3 | <0.001 |
| Comorbidities, n (%) | |||||
| Congestive heart failure | 71 (18.78) | 816 (17.42) | 766 (15.07) | 868 (17.26) | 0.003 |
| Cardiac arrhythmias | 65 (17.20) | 891 (19.03) | 824 (16.21) | 917 (18.23) | 0.002 |
| Valvular disease | 28 (7.41) | 332 (7.09) | 241 (4.74) | 263 (5.23) | <0.001 |
| Hypertension | 55 (14.55) | 749 (15.99) | 815 (16.03) | 824 (16.38) | 0.794 |
| Renal disease | 75 (19.84) | 907 (19.37) | 977 (19.22) | 973 (19.35) | 0.994 |
| Liver disease | 29 (7.67) | 352 (7.52) | 349 (6.86) | 410 (8.15) | 0.109 |
| Uncomplicated diabetes | 38 (10.05) | 784 (16.74) | 1084 (21.32) | 1556 (30.94) | <0.001 |
| Complicated diabetes | 27 (7.14) | 303 (6.47) | 397 (7.81) | 569 (11.31) | <0.001 |
| Metastatic cancer | 20 (5.29) | 189 (4.04) | 179 (3.52) | 127 (2.53) | <0.001 |
| Coagulopathy | 68 (17.99) | 711 (15.18) | 740 (14.56) | 712 (14.16) | 0.145 |
| Laboratory parameters | |||||
| Anion gap (mmol/L) | 12.94 ± 3.52 | 12.95 ± 3.47 | 12.90 ± 3.39 | 13.13 ± 3.29 | <0.001 |
| Bicarbonate (mmol/L) | 21.48 ± 5.64 | 21.61 ± 4.91 | 21.67 ± 4.48 | 22.20 ± 4.91 | <0.001 |
| Creatinine (mEq/L) | 1.38 ± 1.38 | 1.50 ± 1.66 | 1.49 ± 1.57 | 1.56 ± 1.54 | <0.001 |
| Chloride (mmol/L) | 101.98 ± 7.75 | 102.15 ± 6.51 | 102.61 ± 6.17 | 102.03 ± 6.04 | 0.079 |
| Glucose (mg/dL) | 132.99 ± 40.54 | 136.06 ± 40.48 | 141.39 ± 42.31 | 148.23 ± 45.24 | <0.001 |
| Hematocrit | 27.93 ± 6.11 | 27.69 ± 6.17 | 28.09 ± 6.18 | 28.68 ± 6.25 | <0.001 |
| Hemoglobin (g/dL) | 9.35 ± 2.01 | 9.37 ± 2.12 | 9.52 ± 2.14 | 9.67 ± 2.14 | <0.001 |
| Platelet (109/L) | 211.58 ± 127.66 | 188.25 ± 112.69 | 181.20 ± 101.84 | 188.18 ± 101.33 | <0.001 |
| Sodium (mmol/L) | 136.16 ± 6.05 | 135.72 ± 5.07 | 135.77 ± 4.56 | 135.96 ± 4.84 | 0.005 |
| Potassium (mmol/L) | 3.72 ± 0.60 | 3.71 ± 0.56 | 3.73 ± 0.55 | 3.79 ± 0.57 | <0.001 |
| Lactate (mmol/L) | 1.74 ± 0.95 | 1.76 ± 1.29 | 1.73 ± 1.27 | 1.76 ± 1.19 | 0.130 |
| BUN (mg/dL) | 26.59 ± 21.97 | 26.39 ± 21.27 | 26.03 ± 20.38 | 28.21 ± 21.77 | <0.001 |
| WBC (109/L) | 10.29 ± 6.38 | 10.40 ± 6.73 | 10.77 ± 11.30 | 11.00 ± 6.50 | <0.001 |
| PT (seconds) | 14.89 ± 3.98 | 14.94 ± 4.54 | 14.97 ± 4.79 | 15.14 ± 4.82 | 0.002 |
| APTT (seconds) | 33.71 ± 13.12 | 33.56 ± 12.80 | 32.90 ± 12.48 | 31.67 ± 10.99 | <0.001 |
| INR | 1.37 ± 0.54 | 1.38 ± 0.63 | 1.38 ± 0.61 | 1.40 ± 0.65 | 0.009 |
| Scoring systems | |||||
| SOFA | 4.92 ± 2.96 | 5.17 ± 3.19 | 5.31 ± 3.23 | 5.57 ± 3.34 | <0.001 |
| SAPSII | 40.85 ± 13.49 | 39.71 ± 13.94 | 38.87 ± 13.80 | 38.71 ± 14.22 | <0.001 |
| Alcohol abuse | 15 (3.97) | 277 (5.92) | 307 (6.04) | 317 (6.30) | 0.307 |
| Drug abuse | 11 (2.91) | 166 (3.54) | 136 (2.68) | 119 (2.37) | 0.005 |
| ICU LOS (day) | 5.79 ± 6.59 | 5.96 ± 7.70 | 6.07 ± 8.14 | 6.65 ± 8.31 | <0.001 |
| AKI stage | <0.001 | ||||
| I | 98 (25.93) | 1079 (23.04) | 1119 (22.01) | 920 (18.29) | |
| II | 81 (21.43) | 786 (16.78) | 749 (14.73) | 811 (16.13) | |
| III | 199 (52.65) | 2818 (60.18) | 3216 (63.26) | 3298 (65.58) | |
| 30-day mortality, n (%) | 71 (18.78) | 812 (17.34) | 687 (13.51) | 667 (13.26) | <0.001 |
| 90-day mortality, n (%) | 123 (32.54) | 1155 (24.66) | 982 (19.32) | 923 (18.35) | <0.001 |
| 365-day mortality, n (%) | 177 (46.83) | 1632 (34.85) | 1363 (26.81) | 1260 (25.05) | <0.001 |
BMI: body mass index; SBP: systolic blood pressure; DBP: diastolic blood pressure; MBP: mean blood pressure; BUN: blood urea nitrogen; WBC: white blood cell; PT: prothrombin time; APTT: activated partial thromboplastin time; INR: international normalized ratio; SOFA: sequential organ failure assessment; SAPSII: simplified acute physiology score II; ICU: intensive care unit; LOS: length of stay; AKI: acute kidney injury.