Plasma Creatinine Level Does Not Predict Respiratory Function in Amyotrophic Lateral Sclerosis

In amyotrophic lateral sclerosis (ALS) lower plasma creatinine level has been associated with shorter survival and faster functional decline. It has not been clear if creatinine is associated with respiratory outcome. We analyzed retrospectively a population of unselected ALS patients. Multiple-regression and Cox-regression analyses were performed. We included 233 patients, mean age 62.8, mean disease duration of 18.6 months. At baseline, creatinine was significantly associated with ALSFRS-R, but not with its decline rate. No predictive value was disclosed for FVC, its decline rate, or with survival. We did not confirm that creatinine is a marker of respiratory outcome.