Blood glycated hemoglobin level is not associated with disease progression in amyotrophic lateral sclerosis

Abstract

Objective: A high glycemic index and high glycemic load diet has been associated with slower progression of amyotrophic lateral sclerosis (ALS), suggesting a benefit from high blood glucose levels. We examined the association between average blood glucose level and ALS progression in two independent cohorts. Methods: Sporadic ALS patients enrolled in the ALS Multicenter Cohort Study of Oxidative Stress (ALS COSMOS) who completed a 3-month follow-up visit and had available blood samples were included. Hemoglobin A1c (HbA1c) was measured from whole blood collected at the 3-month follow-up. From the Pooled Resource Open-Access ALS Clinical Trials (PRO-ACT) database, we included ALS patients with one or more HbA1c measurements at enrollment and available death information. Associations between HbA1c with revised ALS functional rating scale (ALSFRS-R)/ALSFRS total score change, and tracheostomy-free survival/survival were examined in these cohorts using linear regression, linear mixed-effects models, and Cox proportional hazard models, adjusted for covariates. Results: In the ALS COSMOS cohort (n = 193), HbA1c level was not significantly associated with the change in the ALSFRS-R total score from baseline to the 3-month follow-up (p = 0.8) nor baseline to the 6-month follow-up (p = 0.4). No significant association was found between HbA1c level and tracheostomy-free survival (p = 0.8). In the PRO-ACT cohort (n = 928), no significant association was found between HbA1c level and the rate of ALSFRS decline in the first 200 days (p = 0.81 for interaction) nor between HbA1c level and survival (p = 0.45). Interpretation: We did not find convincing evidence that mean blood glucose level is associated with disease progression among ALS patients.