Comparator supplement patterns qualify the clinical interpretation of an EHR-derived glucosamine signal in Alzheimer's disease.

Electronic health records linked documented glucosamine use to faster progression from mild cognitive impairment (MCI) to Alzheimer's disease (AD) and poorer survival after dementia. We examined these associations in the National Alzheimer's Coordinating Center cohort and compared glucosamine with other supplement records captured in the same medication fields. The estimate for progression to primary AD dementia was in the same risk direction as the original finding, but similar estimates were observed for multivitamin/broad vitamin and calcium/vitamin D records. Among participants with dementia, glucosamine records were not associated with higher adjusted mortality, although death-data limitations reduce certainty. These findings do not address the experimental mechanism, but show that a glucosamine record alone does not establish a glucosamine-specific clinical effect.