Serum dipentidyl peptidase-4 is associated with multiple vertebral fractures in type 2 diabetes mellitus

Objective: Patients with type 2 diabetes mellitus (T2DM) have a high risk of fracture although they have slightly higher bone mineral density (BMD). There is no evidence that dipeptidyl peptidase-4 (DPP-4) is involved in the bone fragility of the patients. The aim of this study was to investigate the association between serum DPP-4 levels and vertebral fractures (VFs) in men with T2DM.

Design: We conducted a cross-sectional study and investigated the relationships between serum DPP-4 levels vs BMD at lumbar spine, femoral neck and radius, bone turnover markers and presence of VFs in 204 Japanese male patients.

Results: Multiple regression analyses adjusted for confounders such as age, duration of diabetes, body mass index, serum creatinine, HbA1c, serum albumin, log(alanine transaminase), and log(C-reactive protein) showed that serum DPP-4 was positively associated with bone formation markers (bone-specific alkaline phosphatase and osteocalcin) as well as a bone resorption marker [tartrate-resistant acid phosphatase 5b (TRACP-5b)] (β = 0・25, P < 0・01; β = 0・17, P < 0・05; and β = 0・30, P < 0・01, respectively), but not BMD at each site. Multivariate logistic regression analyses adjusted for the confounders described above revealed that serum DPP-4 levels were associated with the presence of multiple VFs (odds ratio 1・61, 95% confidential interval 1・05-2・49 per SD increase, P < 0・05). This association was still significant after additional adjustment for any sites of BMD or bone turnover markers except for TRACP-5b.

Conclusions: We firstly showed that high level of serum DPP-4 is associated with prevalent multiple VFs independently of BMD and bone formation in men with T2DM.