| Objective To evaluate the effects of sitagliptin and metformin on biomarkers of bone turnover and bone mineral density (BMD) in patients with type 2 diabetes (T2DM) and osteoporosis (OP). Methods Ninety-five patients diagnosed with T2DM and OP at our hospital from January 2015 to January 2016 were randomly assigned into three groups, and were treated with metformin + acarbose (M+A group, n=32), sitagliptin+ acarbose (S+A group, n=31), or metformin + sitagliptin + acarbose (M+S+A group, n=32) for 48 weeks. Body mass index (BMI), serum fasting plasma glucose (FPG), 2-hour postprandial plasma glucose (2h PG), glycated hemoglobin A1c (HbA1c), 25-hydroxyvitamin D [25(OH)D], bone-specific alkaline phosphatase (b-ALP), osteocalcin (OC) and β-c-terminal cross-linked telpeptide (β-CTX) were measured at baseline and at the end of the study. Bone mineral density (BMD) of lumbar spine (L2-4) and femoral neck were measured by dual energy X-ray absorptiometry (DXA) at baseline and at the end of the study. Results Ninety patients completed the treatment, with 30 patients in each group. The mean values of BMI, FPG, 2hPG and HbA1c were not significantly different among the three groups at baseline (all P>0.05). The mean values of BMI, FPG, 2hPG and HbA1c were significantly lower at the end of the study compared with the baseline values in the three groups (all P<0.05). The mean values of BMI, FPG, 2hPG and HbA1c were significantly lower in M+S+A group at the end of the study compared with M+A group and S+A group (all P<0.05). The mean values of BMI, FPG, 2hPG and HbA1c were not significantly different between M+A group and S+A group at the end of the study (all P>0.05). The mean values of b-ALP, OC, β-CTX and BMD were not significantly different among the three groups at baseline (all P>0.05). The mean values of b-ALP, OC and BMD were significantly higher and β-CTX were significantly lower at the end of the study compared with the baseline values in the three groups (all P<0.05). The mean values of b-ALP, OC and BMD were significantly higher and β-CTX were significantly lower in M+S+A group at the end of study compared with M+A group and S+A group (all P<0.05). The mean values of b-ALP, OC, β-CTX and BMD were not significant different between M+A group and S+A group at the end of the study (all P>0.05). The mean values of 25(OH)D at the end of study were not significantly different from that at baseline in the three groups (all P>0.05). Conclusion Sitagliptin and metformin could promote bone formation and inhibit bone absorption, and thus increase BMD in patients with T2DM and OP. Combination of sitagliptin and metformin has the additive effect on bone metabolism in patients with T2DM and OP . |