Weak bones in diabetes mellitus – an update on pharmaceutical treatment options

Abstract

Objectives: Diabetes mellitus is often associated with a number of complications such as nephropathy, neuropathy, retinopathy and foot ulcers. However, weak bone is a diabetic complication that is often overlooked. Although the exact mechanism for weak bones within diabetes mellitus is unclear, studies have shown that the mechanism does differ in both type I (T1DM) and type II diabetes (T2DM). This review, however, investigates the application of mesenchymal stem cells, recombinant human bone morphogenetic protein-2, teriparatide, insulin administration and the effectiveness of a peroxisome proliferator-activated receptor-ϒ modulator, netoglitazone in the context of diabetic weak bones. Key findings: In T1DM, weak bones may be the result of defective osteoblast activity, the absence of insulin's anabolic effects on bone, the deregulation of the bone–pancreas negative feedback loop and advanced glycation end product (AGE) aggregation within the bone matrix as a result of hyperglycaemia. Interestingly, T2DM patients placed on insulin administration, thiazolidinediones, SGLT2 inhibitors and sulfonylureas have an associated increased fracture risk. T2DM patients are also observed to have high sclerostin levels that impair osteoblast gene transcription, AGE aggregation within bone, which compromises bone strength and a decrease in esRAGE concentration resulting in a negative association with vertebral fractures. Summary: Effective treatment options for weak bones in the context of diabetes are currently lacking. There is certainly scope for discovery and development of novel agents that could alleviate this complication in diabetes patients.