Sodium-Glucose Co-Transporter 2 Inhibitors Increase Serum Level of Total Procollagen Type 1 Amino-Terminal Propeptide and Bone Strength in Japanese Patients With Type 2 Diabetes Mellitus

Background: Diabetes mellitus is known to be associated with an increased risk of bone fracture. We investigated the effects of sodium-glucose co-transporter 2 (SGLT2) inhibitors on bone strength and density in type 2 diabetic patients. Methods: Nineteen Japanese patients with type 2 diabetes mellitus were administered 2.5 mg/day of luseogliflozin or 5 mg/day of dapagliflozin for 6 months. Serum levels of tartrate-resistant acid phosphatase 5b (TRACP-5b), an osteoclastic marker, and total procollagen type 1 amino-terminal propeptide (P1NP), a bone formation marker, were measured and compared with those before the treatment. Bone strength was measured by quantitative ultrasound (QUS), and bone density was evaluated by dual-energy X-ray absorptiometry (DEXA). Results: SGLT2 inhibitors significantly increased the calcaneal bone strength as measured by QUS compared to that in young adult mean. However, there was no effect in the lumbar spine density as measured by DEXA after administration. The drug treatment had no effect on serum TRACP-5b, but significantly increased serum P1NP. Conclusions: The results imply that the SGLT2 inhibitors improve bone strength while the inhibitors had no effect on bone density. These results suggest that the increase in bone strength was due to improved bone quality through an increase in serum P1NP level. J Endocrinol Metab. 2020;10(3-4):89-93 doi: https://doi.org/10.14740/jem683