Plasma adrenomedullin levels in asthmatic patients

Adrenomedullin (ADM) is a newly discovered endogenous vasorelaxing peptide isolated from phenochromocytoma. Some experimental studies suggest that ADM plays a role in asthma. The purposes of the present study were to assess t he plasma ADM levels in adults with mild to severe asthma and controls and to correlate those with the findings on lung function test results and othe r clinical indices. We recruited 16 mild 10 moderate, and 11 severely asthm atic patients and 12 healthy controls. We measured the plasma concentration s of ADM in patients with asthma and in healthy subjects using RIA. We asse ssed FEV1, FEV1 predicted %, FEV1/FVC, symptom score, IgE, ECP, and morning and evening peak expiratory flow measurements. There was no significant di fference between the asthmatic and the control group ADM levels, which were 26.3 +/- 24.2 pg/mL and 22.9 +/- 17.6 pg/tnl, respectively Furthermore, pl asma ADM levels increased as the severity of the disease increased in asthm atic patients (20.7 +/- 14.4 pg/mL in mild, 25.2 +/- 23.3 pg/mL in moderate , and 35.5 +/- 33.6 pg/mL in severe asthmatics), although they did nos resu lt in arty statistical significance. However the plasma ADM levels correlat ed negatively with the FEV1 levels in the asthmatic group (p < 0.02, r = -0 .37). Peripheral blood eosinophilia, IgE, and ECP levels did not correlate with plasma ADM levels. These results suggest that the measurement of ADM c oncentration in plasma will not be of diagnostic rise in asthma, but may be a reflection of the severity of asthma.