Table 3.
Significant predictors of ADMA serum level and Raw determined with simple and multiple (for Raw only) linear regression for the whole population of COPD patients (n=74)
| Parameters | Coefficient (95% CI) | P-value |
|---|---|---|
| Simple linear regression of ADMA (log transformed) | ||
| Smoker | 0.13 (0.006, 0.26) | 0.039 |
| Log SDMA | 1.28 (0.93, 1.63) | <0.001 |
| Fibrinogen | 0.11 (0.034, 0.19) | 0.006 |
| Log Raw | 0.13 (0.012, 0.24) | 0.030 |
| Simple linear regression of Raw (log transformed) | ||
| Age | 0.019 (0.0076, 0.031) | 0.002 |
| Height | −1.72 (−2.97, −0.47) | 0.008 |
| Uric acid | 0.0017 (0.00050, 0.0029) | 0.006 |
| Fibrinogen | 0.18 (0.014, 0.34) | 0.034 |
| CRP (normal/high) | 0.61 (0.35, 0.87) | <0.001 |
| Log ADMA | 0.51 (0.049, 0.96) | 0.030 |
| SDMA | 0.94 (0.032, 1.85) | 0.043 |
| FVC | −0.32 (−0.44, −0.19) | <0.001 |
| FVC% pred | −0.0087 (−0.015, −0.0020) | 0.012 |
| FEV1 | −0.42 (−0.56, −0.28) | <0.001 |
| FEV1 % pred | −0.011 (−0.016, −0.0051) | <0.001 |
| FEV1/FVC | −0.015 (−0.024, −0.0059) | 0.002 |
| FEF25–75% | −0.38 (−0.50, −0.25) | <0.001 |
| Log FEF25–75% % pred | −0.49 (−0.68, −0.31) | <0.001 |
| RV/TLC% | 0.024 (0.013, 0.035) | <0.001 |
| RV/TLC% pred | 0.0080 (0.0025, 0.013) | 0.005 |
| IC/TLC | −2.22 (−3.45, −0.98) | 0.001 |
| Corticosteroid use | 0.31 (0.023, 0.60) | 0.035 |
| SGRQ Symptoms score | 0.0042 (−0.000083, 0.0086) | 0.054 |
| SGRQ Activity score | 0.0063 (0.0014, 0.011) | 0.012 |
| SGRQ Impacts score | 0.0055 (−0.00023, 0.011) | 0.060 |
| SGRQ Total score | 0.0060 (0.00033, 0.012) | 0.038 |
| Multiple linear regression of Raw (log transformed) | ||
| Log ADMA | 0.42 (0.062–0.771) | 0.022 |
| Log FEF25–75% % pred | −0.336 (−0.517, −0.154) | <0.001 |
| CRP (normal/high) | 0.489 (0.266, 0.713) | <0.001 |
Notes: The Symptoms and Impacts scores are also included, although these are on the verge of significance. Regression coefficient values are presented with their 95% CIs. The initial model for the multiple regression analysis consisted of the significant parameters provided by the simple regression and the relevant a priori identified parameters (the latter ones were omitted from the present table as they did not contribute significantly to the final model). Bold represents statistically significant values.
Abbreviations: ADMA, asymmetric dimethylarginine; Raw, airway resistance; CI, confidence interval; SDMA, symmetric dimethylarginine; CRP, C-reactive protein; FVC, forced vital capacity; FEV1, forced expiratory volume in 1 s; FEF25–75%, forced expiratory flow between 25% and 75% of FVC; RV, residual volume; TLC, total lung capacity; IC, inspiratory capacity; SGRQ, St George’s Respiratory Questionnaire.