The aim of this study is to evaluate the association between changes in routinely prescribed laboratory tests and tracheostomy-free survival in amyotrophic lateral sclerosis (ALS). Two hundred seventy-five ALS patients were retrospectively studied. BMI, forced vital capacity, hemoglobin, hematocrit, lymphocytes, cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides, proteins, albumin, creatine-phosphokinase, iron, ferritin, transferrin, glucose, urea, uric acid, and creatinine were measured every 6 months from baseline to 24 months, death or study end, together with the probability of death or tracheostomy. Missing data were handled using multiple imputation chained equations. Hemoglobin (OR = 1.71, 95%CI 1.24-2.36 for IQR increase), hematocrit (OR = 1.87, 95%CI 1.34-2.63 for IQR increase), urea (OR = 1.51, 95%CI 1.21-1.89 for IQR increase), and uric acid (OR = 1.98, 95%CI 1.23-3.20 for IQR increase) were directly associated, while triglycerides (OR = 0.69, 0.51 to 0.93 for IQR increase) were inversely associated with the odds of death or tracheostomy. In our cohort, an increase of hemoglobin, hematocrit, urea, and uric acid was directly associated, and an increase of triglycerides was inversely associated with the odds of death or tracheostomy. Should these findings be replicated in an external cohort, they might help to discriminate ALS progression and patients' decisions about procedures and end of life.
Keywords: Amyotrophic lateral sclerosis; Hematocrit; Hemoglobin; Routine laboratory tests; Urea; Uric acid.