Patients with Legionnaires ' disease more frequently had low sodium levels ( Na < 130mmol/L ) ( 44.4 % vs 8.2 % , p < 0.01 ) , but similar mean CT-ProVasopressin levels ( pmol/l ) ( 39.4 [ 7 ] vs 51.2 [ 2.7 ] , p = 0.43 ) as compared to patients with pneumonia of other etiologies .