Table 2 Background characteristics and clinical variables: severe COVID-19 patients as a function of urinary cadmium/creatinine quartiles
Variables | First Quartile | Second Quartile | Third Quartile | Fourth Quartile | p value |
|---|---|---|---|---|---|
(U-CdCr < 2.2 μg/g) | (2.2 ≤ U-CdCr < 3.8 μg/g) | (3.8 ≤ U-CdCr < 8.8 μg/g) | (U-CdCr ≥ 8.8 μg/g) |  | |
(n = 63) | (n = 63) | (n = 63) | (n = 63) |  | |
Age (years) | 64.8 ± 16.8 | 71.8 ± 14.9 | 73.5 ± 13.4 | 73.3 ± 12.4 | 0.002 |
Male (gender) | 46 (73%) | 41 (65.1%) | 42 (66.7%) | 38 (60.3%) | 0.425 |
Body mass index (kg/m2) | 25.0 ± 5.9 | 24.9 ± 4.6 | 22.7 ± 4.5 | 22.2 ± 4.1 | 0.001 |
Smoking history | |||||
 Current | 9 (14.3%) | 7 (11.1%) | 7 (11.1%) | 4 (6.3%) | 0.870 |
 Former | 7 (11.1%) | 7 (11.1%) | 7 (11.1%) | 6 (9.5%) |  |
Never | 47 (74.6%) | 49 (77.8%) | 49 (77.8%) | 53 (84.1%) | Â |
Cerebrovascular accident | 7 (11.1%) | 8 (12.7%) | 12 (19%) | 10 (15.9%) | 0.640 |
Hypertension | 33 (52.4%) | 35 (55.6%) | 30 (47.6%) | 27 (42.9%) | 0.465 |
Diabetes mellitus | 27 (42.9%) | 27 (42.9%) | 25 (39.7%) | 26 (41.3%) | 0.958 |
Chronic heart disease | 23 (36.5%) | 13 (20.6%) | 13 (20.6%) | 16 (25.4%) | 0.110 |
Chronic lung disease | 6 (9.5%) | 9 (14.3%) | 7 (11.1%) | 12 (19%) | 0.418 |
Chronic liver disease | 11 (17.5%) | 7 (11.1%) | 7 (11.1%) | 3 (4.8%) | 0.149 |
Chronic kidney disease | 14 (22.2%) | 13 (20.6%) | 14 (22.2%) | 11 (17.5%) | 0.898 |
Immunocompromised status | 20 (31.7%) | 12 (19%) | 19 (30.2%) | 24 (38.1%) | 0.125 |
APACHE II at diagnosis | 14.7 ± 7.8 | 15 ± 5.6 | 17.5 ± 5.9 | 18.9 ± 6.3 | 0.001 |
SOFA score at diagnosis | 4.8 ± 3.5 | 5.1 ± 3.3 | 5.8 ± 3.7 | 6.4 ± 4.0 | 0.026 |
WBC (103/µL) | 10 ± 5 | 11.8 ± 13.1 | 10.9 ± 6.1 | 12.3 ± 9.6 | 0.489 |
Neutrophil (%) | 79.8 ± 13 | 80.9 ± 13.1 | 79.2 ± 19.4 | 81.9 ± 15.4 | 0.759 |
Lymphocyte (%) | 11 ± 7.5 | 11.5 ± 12 | 10.4 ± 9.2 | 10.8 ± 12.4 | 0.943 |
Neutrophil/lymphocyte ratio | 9.5 (5–16) | 9.8 (5.8–15.8) | 10.3 (4.7–19.5) | 12.8 (6.8–26.7) | 0.02 |
Hemoglobin (g/dL) | 11.6 ± 2.7 | 12 ± 2.4 | 10.9 ± 2.5 | 11.3 ± 2.6 | 0.098 |
Platelets (103/µL) | 203.6 ± 92.4 | 215.8 ± 105.5 | 187.9 ± 105.8 | 230.7 ± 128 | 0.155 |
Serum creatinine (mg/dL) | 1.3 (0.8–1.9) | 1.1 (0.7–1.5) | 1.1 (0.7–1.9) | 1 (0.6–1.6) | 0.252 |
Ferritin (ng/mL) | 707 (352.5–1026) | 680 (403–976.5) | 985 (650.8–1221.3) | 1119 (526–1881) | 0.007 |
LDH (U/L) | 262 (203.5–334) | 271 (215–354) | 320 (248.3–392.5) | 343 (263.8–431.3) | 0.548 |
CRP (mg/L) | 54 (13.3–169.5) | 108.5 (38.9–155.3) | 123.2 (52.6–157.9) | 126.2 (60.9–175.6) | 0.139 |
IL-6 (pg/mL) | 6 (18.3–56.7) | 15.1 (6.5–42.1) | 48 (19–97.7) | 59.8 (23.2–196.5) | 0.324 |
Blood cadmium (μg/L) | 0.7 ± 0.3 | 0.9 ± 0.4 | 1.0 ± 0.6 | 1.3 ± 0.8 |  < 0.001 |
Blood nickel (μg/L) | 1.5 ± 0.1 | 1.6 ± 0.6 | 1.5 ± 0.1 | 1.5 ± 0.1 | 0.446 |
Urine cadmium/creatinine (μg/g) | |||||
 mean ± SD | 1.2 ± 0.6 | 2.9 ± 0.4 | 6 ± 1.5 | 31.9 ± 50.9 |  < 0.001 |
 median (IQR) | 1.3 (0.7–1.7) | 2.9 (2.6–3.3) | 6 (4.8–6.8) | 16.5 (11.7–27.4) |  < 0.001 |
Urine nickel (μg/L) | |||||
 mean ± SD | 2.7 ± 2.5 | 3.9 ± 8.4 | 4.2 ± 7.6 | 3.6 ± 5.0 | 0.661 |
 median (IQR) | 1.5 (1.4–2.7) | 1.7 (1.4–3.0) | 2.1 (1.4–3.1) | 1.9 (1.4–2.9) | 0.661 |
PaO2/FiO2 (mm Hg) | 220.8 (136–287.7) | 149 (103.8–240.2) | 147.2 (97.8–203.7) | 134 (103.8–204.3) | 0.032 |
Type of respiratory support | |||||
 Nasal cannula | 23 (36.5%) | 18 (28.6%) | 5 (7.9%) | 5 (7.9%) |  < 0.001 |
 Simple mask | 5 (7.9%) | 8 (12.7%) | 10 (15.9%) | 4 (6.3%) | 0.310 |
 High-flow nasal cannula | 4 (6.3%) | 4 (6.3%) | 5 (7.9%) | 1 (1.6%) | 0.443 |
 Nonrebreathing mask | 2 (3.2%) | 2 (3.2%) | 5 (7.9%) | 2 (3.2%) | 0.486 |
 Invasive mechanical ventilation | 29 (46%) | 31 (49.2%) | 38 (60.3%) | 51 (81%) |  < 0.001 |