Diabetic bone fragility through advanced glycation end product-collagen axis: Mechanisms and therapy of sodium glucose cotransporter 2 inhibitors

Abstract

Type 2 diabetes markedly elevates fracture risk despite normal or high bone mineral density, a paradox reflecting qualitative skeletal deficits rather than loss of mass. Chronic hyperglycemia fosters the accumulation of advanced glycation end products in bone; their nonenzymatic crosslinks stiffen type I collagen, impair mineralization, and erode mechanical strength. By engaging the receptor for advanced glycation end products, these adducts activate nuclear factorκB and mitogen-activated protein kinase cascades, amplifying oxidative stress, inflammation, osteoblast dysfunction, and osteoclastogenesis. This review synthesizes epidemiological data from type 1 and type 2 diabetes, highlights the limits of densitybased skeletal assessment, and details the molecular pathology of the glycation-collagen axis. It also appraises antiglycation therapies, including formation inhibitors, crosslink breakers and receptor antagonists, with a particular focus on sodium-glucose cotransporter 2 inhibitors that couple glycemic control with modulation of the glycation pathway. By integrating recent basic and clinical advances, we propose a mechanistic framework for diabetic bone disease and outline strategies to mitigate glycationdriven skeletal fragility.

Keywords: Advanced glycation end products; Bone mineralization and microstructural heterogeneity; Bone mineral density; Diabetic bone fragility; High-resolution peripheral quantitative computed tomography; Nonenzymatic collagen cross-linking; Oxidative stress; Sodium-glucose cotransporter 2 inhibitors; Type I collagen

Core Tip: This review highlights how advanced glycation end products (AGEs) exacerbate bone fragility in type 2 diabetes by cross-linking type I collagen and disrupting bone mineralization. These findings elucidate the AGE-type I collagen axis as a key pathogenic mechanism underlying the diabetic bone paradox. Emerging evidence suggests that sodium-glucose cotransporter 2 inhibitors may mitigate AGE-related bone damage beyond glycemic control. Targeting AGE formation, cross-linking, and receptor-mediated signaling offers novel therapeutic strategies to improve bone quality in diabetic patients.