Adults with type 1 diabetes and an HbA1c of at least 8% were more likely to sustain a low-trauma fracture in the 4 years after diabetes diagnosis than similar adults with an HbA1c of less than 7%, according to findings from a case-control study .
In an analysis of more than 47,000 adults, researchers did not observe the same fracture association for adults with type 2 diabetes; however, the risk for fracture was elevated in adults with type 2 diabetes prescribed rosiglitazone (Avandia, GlaxoSmithKline) or pioglitazone, independent of glycemic control.
“In patients diagnosed with [type 1 diabetes] during adolescence and early adulthood, deficiencies in insulin and insulin-like growth factor I seem to impair osteoblast function leading to lower bone mass, smaller bone size and alterations in bone microstructure,” Janina Vavanikunnel, MD, a research fellow in the division of endocrinology, diabetes and metabolism at University Hospital Basel, Switzerland, and colleagues wrote in the study background. “In contrast, patients with [type 2 diabetes], who usually suffer from obesity-related insulin resistance and hyperinsulinemia, present[ed] with normal to increased bone mass and preserved or even increased trabecular bone volume, but with increased cortical porosity. This pattern is found particularly in patients with fractures and microvascular complications.”