The prevalence of type 2 diabetes mellitus among people with amyotrophic lateral sclerosis is increasing in the United States

Background: Type 2 diabetes mellitus (T2DM) has been associated with lower risk of ALS and prevalence of comorbid T2DM has been reported to be lower among people with ALS (PALS) compared to general population. We examined the trend of comorbid DM prevalence among PALS in comparison to overall population from 2011 to 2021 in the United States (US). Methods: We used multi-center electronic health records (EHRs) data within the GPC Reusable Observable Unified Study Environment (GROUSE) and validated algorithms to identify PALS with T2DM. Prevalence was defined by number of cases per population in each year. The trend of changes in prevalences from 2011 to 2021 was examined using mixed linear models, adjusted for age and sex. Results: A total of 25,676,029 unique persons included in the EHRs from 2011 to 2021 were identified. Among them, 1,720,524 (6.7%) had T2DM, 12,388 (0.05%) had ALS, and 1,498 (0.006%) had both ALS/T2DM. Among PALS, prevalence of T2DM increased from 5.2% in 2011 to 12.1% in 2021, 132.7% relative increase in this period. In the overall population, T2DM prevalence increased from 5.9% in 2011 to 7.6% in 2021, a relative increase of 29% in the same period. In the overall population, ALS prevalence increased from 30.2 per 100,000 in 2011 to 33.0 per 100,000 in 2021, a 9.3% increase. In contrast, ALS prevalence increased dramatically among T2DM by 118.7% from 14.4 per 100,000 in 2011 to 31.5 per 100,000 in 2021. Discussion: Prevalence of ALS among T2DM have increased significantly over the past decade, out pacing the trend among general population. Etiologies behind this trend need to be further investigated.