Table 2.
Variables associating with individual GDF15 concentrations in multivariable linear regression analysis
| Model with variables explaining serum GDF15 concentrations upon ICU admission | Scaled estimate (95%CI) | p value |
|---|---|---|
| ICU-independent variables | ||
| Age | 353 (− 528; 1234) | 0.43 |
| BMI | − 674 (− 2057; 709) | 0.33 |
| History of diabetes mellitus | 731 (314; 1147) | 0.0006 |
| History of malignancy | 485 (60; 909) | 0.02 |
| NRS score of ≥ 5 vs < 5 | 424 (− 24; 872) | 0.06 |
| ICU-related variables | ||
| Admission diagnosis | ||
| Cardiac surgery | 16 (− 761; 793) | 0.96 |
| Elective other surgery | 1566 (445; 2687) | 0.006 |
| Emergency other surgery | − 1256 (− 2013; − 499) | 0.001 |
| Medical disease | − 326 (− 1477; 824) | 0.57 |
| APACHE-II score | 4454 (3211; 5697) | < 0.0001 |
| Sepsis upon admission | 2232 (594; 3869) | 0.007 |
| Infection upon admission | − 1412 (− 3059; 234) | 0.09 |
| Mechanical ventilation on ICU day 1 | 296 (− 452; 1044) | 0.43 |
| Steroids on ICU day 1 | 703 (212; 1194) | 0.005 |
| Laboratory parameters | ||
| Blood glucose upon ICU admission | − 1975 (− 4405; 455) | 0.11 |
| Plasma creatinine on ICU day 1 | 22,102 (19,679; 24,526) | < 0.0001 |
| Plasma total bilirubin on ICU day 1 | 13,569 (10,097; 17,041) | < 0.0001 |
| Plasma CRP on ICU day 1 | − 1605 (− 3132; − 78) | 0.03 |
Scaled estimates are shown for all variables included in the linear regression model built to explain individual GDF15 concentrations upon ICU admission. Age, BMI, APACHE-II score, and the laboratory parameters were added as continuous variables; all other variables were added as categorical variables. The R2 of the model was 0.23. A sensitivity analysis using BMI (< 18.5 kg/m2, 18.5–25 kg/m2, > 25 kg/m2) and age (18– < 30 years, 30– < 50 years, 50– < 70 years, 70– < 90 years, > 90 years) as categorical variables was performed to rule out non-significant associations in case of non-linear relationships, which also yielded insignificant associations for all categories (data not shown)
Abbreviations: GDF15 growth-differentiation factor-15, ICU intensive care unit, BMI body mass index, NRS nutritional risk screening, APACHE acute physiology and chronic health evaluation, CRP C-reactive protein