Sitagliptin's effects on bone tissue and osseointegration in diabetic rats.

OBJECTIVE

To investigate the effects of sitagliptin, a dipeptidyl peptidase 4 inhibitor used to treat type II diabetes, on bone tissue and on implant osseointegration in diabetic rats.

DESIGN

Thirty-two male rats were divided into four groups: 1) Diabetic animals (GD); 2) Diabetic animals that received sitagliptin (GDS); 3) Normoglycemic animals (GN); and 4) Normoglycemic animals that received sitagliptin (GNS). All animals received titanium implants in the right tibia. Sitagliptin or water were administered for 4 weeks. Glycemia, HOMA-IR, insulinemia, microtomographic parameters of the left tibia and implant bone area fraction occupancy (BAFO) of the right tibia were evaluated.

RESULTS

The model used to induce diabetes led to hyperglycemia. However, HOMA-IR results showed no insulin resistance, and insulinemia was lower in diabetic animals, demonstrating the development of type I diabetes. Sitagliptin administration did not influence glycemic control. The diabetic animals showed a lower BAFO and bone volume fraction, as well as a lower trabecular number and thickness, revealing the deleterious effect of diabetes on bone metabolism and osseointegration.

CONCLUSION

In this model, sitagliptin administration did not reverse the negative effects of type I diabetes on bone, suggesting that sitagliptin has no direct action on bone tissue and has no protective bone action in decompensated diabetic animals.