Dapagliflozin has no effect on markers of bone formation and resorption or bone mineral density in patients with inadequately controlled type 2 diabetes mellitus on metformin

Aims Dapagliflozin, a selective sodium-glucose cotransporter 2 (SGLT2) inhibitor, reduces hyperglycaemia in patients with type 2 diabetes (T2DM) by increasing urinary glucose excretion. Owing to its mechanism of action, dapagliflozin could potentially affect the renal tubular transportation of bone minerals. Therefore, markers of bone formation and resorption and bone mineral density (BMD) were evaluated in patients with T2DM after 50?weeks of dapagliflozin treatment. Methods This international, multi-centre, randomized, parallel-group, double-blind, placebo-controlled study (ClinicalTrials.gov NCT00855166) enrolled patients with T2DM (women 5575?years and men 3075?years; HbA1c 6.58.5%; BMI?=?25?kg/m2; body weight?=?120?kg) whose T2DM was inadequately controlled on metformin. One hundred and eighty-two patients were randomly assigned 1:1 to receive dapagliflozin 10?mg/day or placebo added to open-label metformin for a 24-week double-blind treatment period followed by a 78-week site- and patient-blinded extension period. At week 50, serum markers of bone formation (procollagen type 1 N-terminal propeptide; P1NP) and resorption (C-terminal cross-linking telopeptides of type I collagen; CTX), bone mineral density (BMD) as assessed by standardized Dual-Energy X-ray Absorptiometry (DXA) measurements and adverse events of fracture were evaluated as safety objectives. Results One hundred and sixty-five patients (90.7%) completed the first 50 weeks. Compared with placebo, no significant changes from baseline in P1NP, CTX or BMD were identified over 50 weeks of dapagliflozin treatment, with no significant treatment-by-gender interactions. No fractures were reported. Conclusions Dapagliflozin had no effect on markers of bone formation and resorption or BMD after 50 weeks of treatment in both male and post-menopausal female patients whose T2DM was inadequately controlled on metformin.