Abstract

Type 2 diabetes is a major risk factor for fragility fractures, yet the contributors to skeletal fragility remain unclear. Through integrated clinical metabolomics, in vivo , and in vitro analyses, we identify maltol—a widely used food additive—as a previously unrecognized risk factor for hyperglycemia-associated bone fragility. Metabolomic profiling of femoral neck tissue from individuals with fragility fractures showed diabetes-associated maltol accumulation, and elevated circulating maltol levels correlated with increased fracture incidence. Mechanistically, maltol inhibits osteoblast differentiation via Wnt/β-catenin and promotes osteoclast maturation through nuclear factor κB (NF-κB) signaling, disrupting bone remodeling. These effects are amplified under hyperglycemia, while insulin reversal of glucose levels mitigates maltol-induced skeletal deterioration in mouse models. Given the widespread use of maltol in processed foods, these findings suggest that food additive safety should consider metabolic context and call for disease-specific dietary exposure guidelines to reduce fracture risk in diabetes.